CBSE

In this page, you can find CBSE Class 10 Science Chapter 14 Extra Questions and Answers Sources of Energy Pdf free download, NCERT Extra Questions for Class 10 Science will make your practice complete.

Class 10 Science Chapter 14 Extra Questions and Answers Sources of Energy

Extra Questions for Class 10 Science Chapter 14 Sources of Energy with Answers Solutions

Sources of Energy Extra Questions Very Short Answer Type

Question 1.
What type of reactions occur inside the Sun which produces solar energy?
Answer:
The nuclear fusion reactions taking place inside the Sun produce solar energy.

Question 2.
Which of the following are renewable and which are non-renewable sources of energy?
Coal, wind, tides, sum, petrol, biomass, CNG, hydro energy.
Answer:
Renewable sources: wind, tides, SuN, biomass, hydro energy
Non-renewable sources: coal, petrol, CNG

Question 3.
Which part of Sun’s energy is responsible for drying clothes and exposure to which part could be a health hazard?
Answer:
Infra-red (IR) radiations are responsible for drying clothes and ultraviolet (UV) radiations could be a health hazard.

Question 4.
What type of energy is possessed by wind?
Answer:
Kinetic energy.

Question 5.
Though a hot iron emits radiations, yet it is not visible in the dark, why?
Answer:
Hot iron emits infrared rays. These rays are invisible to the eyes.

Question 6.
What is bagasse?
Answer:
Bagasse is the remaining part of the sugarcane from which juice has been extracted.

Question 7.
Define anaerobic degradation.
Answer:
The decomposition which takes place in the absence of oxygen by anaerobic bacteria is called anaerobic degradation.

Question 8.
Name the main constituent of biogas.
Answer:
The main constituent of biogas is methane (75%).

Question 9.
What is the minimum wind velocity required for obtaining useful energy with a windmill?
Answer:
Minimum velocity required for obtaining useful energy with a windmill is about 15 km/h.

Question 10.
Name two forms of energy in which solar energy manifests itself in oceAnswer:
Answer:
(i) Tidal energy, and (ii) Ocean thermal energy.

Question 11.
Name any two materials that are used for making solar cells.
Answer:
(i) Silicon, and (ii) Gallium or selenium.

Question 12.
What is the range of wavelength of electromagnetic waves that constitute visible radiation?
Answer:
The range of electromagnetic waves is about 4000 Å to 7000 Å, which constitute visible radiation.

Question 13.
What steps would you suggest to help minimise environmental pollution caused by burning of fossil fuels?
Answer:

1. Use of smokeless appliances
2. Afforestation.

Question 14.
State the two forms of energy in which energy is mainly utilised at our homes.
Answer:

1.  Heat energy, and
2. light energy.

Question 15.
What are the different types of nuclear reactions?
Answer:
There are two types of nuclear reactions:

1. Nuclear fission,
2. Nuclear fusion.

Question 16.
Why does acid rain happen?
Answer:
Acid rain happens because of burning of fossil fuels which release oxides of carbon, nitrogen and sulphur in the atmosphere.

Question 17.
What energy transformations occur in a hydro powr plant?
Answer:
In a hydro power plant potential energy possessed by stored water is converted into electrical energy

Question 18.
What is a chain reaction?
Answer:
A reaction in which the particle which initiates (starts) the reaction is also produced during the reaction to carry on the reaction further and further is called a chain reaction.

Sources of Energy Extra Questions Short Answer Type

Question 1.
What is the use of the black painted surface in solar heating devices?
Answer:
Black colour is a very good absorber of heat but a very poor reflector. So, it is used to absorb the maximum amount of heat from the sunlight. It is used in solar heating devices to maximise the absorption of heat and to minimise heat loss due to reflection.

Question 2.
Give an example of indirect harnessing of solar energy.
Answer:
All green plants prepare carbohydrates from carbon dioxide and water in the presence of sunlight by the process of photosynthesis. All non-green plants and animals directly or indirectly consume food from the green plants (producers) and store this food in their bodies in the form of chemical energy. In other words, solar energy is transformed into chemical energy.

Question 3.
State the important uses of wind energy.
Answer:
The wind energy is used:

1. To generate electricity.
2. To grind the wheat in flour mills.
3. To run a pump to draw water from the ground.

Question 4.
Write two advantages of classifying energy soruces as renewable and non renewable.
Answer:
(i) The classification helps us to decide which of the available energy sources need to be conserved to ensure their availability for future generations.
(ii) The classification helps us to look for alternative sources of energy like solar and wind energy. It has, therefore, accelerated the pace of development of technologies suitable for harnessing new sources of energy.

Question 5.
Why is tidal energy not likely to be a potential source of energy?
Answer:
The tidal energy is not likely to be a potential source of energy because:

1. Only few sites are available around the world which are suitable for building field barrages, and
2. The rise and fall of sea water during high and low tides is not enough to generate electricity on a large scale.

Question 6.
Why is it not possible to make use of solar cells to meet all our energy needs? State at least two reasons to support your answer.
Answer:

1. In the solar cells, the energy is obtained only during the day, when the Sun shines.
2. In the solar cells, the solar panel convert solar energy into electricity, which is stored in storage battery.

The storage battery give the direct current but all the appliancesd are working by the alternating current, so first of all direct current is converted into alternating current by any suitable appliances before it can be used to run various devices. So, it increases the cost of using solar panels as the source of energy.
So, the solar cell is not used to meet all our energy needs.

Question 7.
How is nuclear energy generated during nuclear fusion?
Answer:
During fusion, two nuclei of light element combine to form a heavy nucleus with the release of tremendous amount of energy. There is some loss of mass during fusion process which is transformed into tremendous amount of energy.

Question 8.
Firewood is a conventional fuel. List any four reasons for replacing it with alternate sources of energy.
Answer:

1. Wood has low colorific value as compared to other sources of fuel.
2. It causes air pollution on burning.
3. Cutting down of trees causes depletion of forest leading to inbalance in nature.
4. Only 8-10% energy of burning firewood is utilised and the remaining is wasted.

Question 9.
State two advantages and two disadvantages of geothermal energy.
Answer:
Advantages:

• The use of geothermal energy does not cause any pollution.
• The use of geothermal energy is quite economical.

Disadvantages:

• It is not available everywhere.
• Deep drilling in the Earth to obtain geothermal energy is very difficult.

Question 10.
What is biogas? Why is biogas considered an ideal fuel for domestic use?
Answer:
Biogas isa combustible mixture of methane (about 75%), carbon dioxide, hydrogen and hydrogen sulphide gas. It is obtained by anaerobic decomposition of human and animal excreta and agricultural and urban waste materials.
Biogas is considered an ideal fuel for domestic use because of the following reasons:

1. It has high calorific value.
2. It does not produce smoke.

Question 11.
Why is biogas a better fuel than animal dung cakes?
Answer:
Biogas is a better fuel than animal dung cakes because:

1. Burning of animal dung cake causes lot of pollution whereas biogas is a smokeless fuel.
2. The calorific value of animal dung cake is much lower than that of biogas.
3. Animal dung cakes leave residue after burning whereas biogas leaves no residue.

Question 12.
What causes the wind to blow?
Answer:
The Sun rays fall on the equatorial region more intensively than on any other part of the Earth. Thus, the hot air of equatorial region, being lighter, rises upwards and cooler air from polar region starts blowing towards the equator to fill the space vacated by hot air. This moving air is called wind. Therefore, Sun’s energy causes winds on the Earth.

Question 13.
Give some uses and advantages of solar energy.
Answer:
Uses:

1. For cooking food in a solar cooker.
2. For heating water in solar geysers.
3. For generating electricity in space satellites, calculators, watches, etc., by solar cells.
4. For generating electricity on a large scale by a solar power plant.
5. To melt metals in solar furnaces.

Advantages:

• It does not cause any pollution.
• It is a renewable source of energy.
• It is free of cost.

Question 14.
State the important uses of solar cells.
Answer:
Solar cells are used:

1. for providing electricity in artificial satellites.
2. for lighting the street lights, traffic signals, running television sets and radio sets in remote areas.
3. for providing electricity in lighthouses.
4. for operating electronic watches and calculators.

Question 15.
Explain solar cell panel.
Answer:
A solar cell is a device which converts solar energy directly into electricity. A group of solar cells is called a solar cell panel. It consists of a large number of solar cells joined together in a definite pattern. It provides a lot of electric energy required by artificial satellites, water pumps, street lighting, etc. For joining the various solar cells in a solar panel, silver wires are used because silver metal is the best conductor of electricity having a very low resistance and which also increases efficiency.

Question 16.
Explain why only a small part of the solar energy that strikes the upper regions of atmosphere reaches the surface of the Earth.
Answer:
When the solar energy falls on the top surface of the atmosphere then the following happens:
(i) Some solar energy is reflected back into the space by the atmosphere, and
(ii) The atmosphere also absorbs a lot of solar energy; for example, most of the ultraviolet rays are absorbed by the ozone layer.
So, the solar energy which reaches us through the Earth’s atmosphere are mainly in the form of heat rays (infra red rays) and visible light, which is a small part of the solar energy.

Question 17.
Why is charcoal considered a better fuel than wood? What are the disadvantages of converting wood into charcoal?
Answer:
Charcoal is considered a better fuel than wood because:

• It has high calorific value.
• It does not produce any smoke.

Disadvantages:

• 1 kg of wood on destructive distillation produces only 0.25 kg of charcoal making it an expensive fuel.
• For production of charcoal, more and more trees would have to be cut down which causes deforestation and disturbs the ecological balance of the Earth.

Question 18.
Explain how the energy of flowing water is related to solar energy.
Answer:
When solar energy falls on the water surface then evaporation of water from water surfaces like oceans, rivers and other water bodies takes place to form clouds. The clouds are then taken to distant places by air currents, and ultimately water comes back to the surface in the form of rain and snow. During evaporation, a part of solar energy gets converted into potential energy of water molecules. The potential energy of water molecules gets converted into kinetic energy during rain and snowfall.

Thus, energy of water flowing in a river is considered to be an indirect form of solar energy.

Question 19.
Mention any two advantages and two disadvantages of producing hydroelectricity by building dams on rivers..
Answer:
Advantages:

• The generation of electricity from water does not produce any environmental pollution.
• Water energy is a renewable source of electric energy which will never get exhausted.

Disadvantages:

• A vast variety of flora and fauna (plants and animals) get affected.
• Dams can be constructed only at a limited number of places.

Question 20.
What is the importance of hydro power plants in India? Describe how electric energy is generated in such plants.
Answer:
Importance: Hydro power plants are of prime importance as about 25 per cent of our energy requirement in India is met by hydro power plants.
(i) A high rise dam is constructed at a suitable place on the river to obstruct the flow of water and thereby, collect water in larger reservoirs. Due to rise in water level the kinetic energy of flowing water is transformed into potential energy of stored water.
(ii) The water from the high level in the dam is carried through sluice gates and pipes to the turbine of electric generator, which is fitted at the bottom of the dam. Due to flowing water, turbine is rotated at a fast rate and hydel electricity is produced.
(iii) A hydro power plant converts the potential energy of falling/stored water into electricity.

Question 21.
(i) Name the device used to convert
(a) solar energy into heat, and (b) solar energy into electricity
(ii) Explain the principle of working of a windmill.
Answer:
(i) (a) Solar energy into heat: Solar cooker.
(b) Solar energy into electricity: Solar cell.
(ii) The wind rotates the blades of the windmill.

This, in turn, rotates the connecting rod (shaft) and the crank (u-bend) moves up and down. Since the pump rod is connected to the crank, the pump rod of the water pump also moves up and down and lifts the water from the well or flooded mine. Thus, the rotational movement of the blades of the windmill is used to drive a large number of machines.

Question 22.
Describe the steps involved in obtaining biogas and explain what is meant by anaerobic decomposition.
Answer:
Following steps are involved in obtaining biogas:

1. Mixing (slurry of cattle-dung and water).
2. Digesting (cattle-dung undergoing decomposition by anaerobic bacteria).
3. Formation of biogas (mixture of methane, CO₂, H₂ and H₂S).
4. Spent slurry (residue left after the formation of biogas).

The process by which the biomass changes into biogas in the absence of air due to an anaerobic microorganisms is termed as an anaerobic decomposition.

Question 23.
Write short on Bio-mass.
Answer:
Bio-mass: The waste material of living things such as cattle dung and dead parts of plants and animals which are used as a source of energy is called biomass. Wood and cow dung are popular biomass used in India. These fuels do not produce much heat on hunting and produce lot of smoke.

Sources of Energy Extra Questions Long Answer Type

Question 1.
Give the construction and working of a solar cooker.
Answer:
A device that utilises solar energy for cooking purposes is called a solar cooker. The most commonly used form of solar cooker is known as box-type solar cooker. A box-type solar cooker is shown in the figure.

Construction of a box-type solar cooker: A box-type solar cooker consists of the following components:
(i) Box (B): This is an insulated metal or a wooden box. It is painted black from inside because black surface absorbs more heat. The box may be provided with four roll-wheels. There is a thermocol layer between the wooden box and the inner metal box.

(ii) Glass cover (G): A cover made of two sheets of toughened glass held together in an aluminum frame is used as a cover of the box B.

(iii) Plane mirror reflector (R): A plane mirror reflector fixed in a frame is fixed to the box B with the help of hinges. The mirror reflector can be positioned at any desired angle to the box. The mirror is positioned so as to allow the reflected sunlight fall on the glass cover of the box.

(iv) Cooking containers (C): A set of containers made of aluminum and blackened from outside are kept in the box B. These containers are also painted black because black surface absorbs more heat.

Working: The food is cooked in a shallow vessel of the container. The box has a transparent covering of glass sheet over it. The solar cooker is placed in sunlight and reflector (plane mirror) is adjusted in such a way that a strong beam of sunlight enters the box through the glass sheet. The blackened metal surfaces in the wooden box absorb infra-red radiations from the beam of sunlight and heat produced raises the temperature of blackened metal surface to about 100°C.

The food absorbs heat from the black surface and gets cooked. The thick glass sheet does not allow the heat produced to escape and thus, helps in raising the temperature in the box to a sufficiently high degree to cook the food. The thermocol layer also does not allow the heat to escape and thus the temperature inside is maintained.

Question 2.
(a) Distinguish between renewable and non-renewable sources of energy.
(b) Choose the renewable sources of energy from the following list.
Coal, biogas, Sun, natural gas
Answer:

(b) Sun and biogas.

Question 3.
What is biogas? Describe the working of a biogas plant with the help of a labelled diagram.
Answer:

Biogas is a mixture of methane, carbon dioxide, hydrogen and hydrogen sulphide. The major constituent of biogas is methane. Biogas is produced by the anaerobic degradation of animal wastes like cow-dung or plant wastes in the presence of water.

The biogas plant has a dome-like structure built with bricks.A slurry of cow-dung and water is made in the mixing tank from where it is fed into the digester. The digester is a sealed chamber in which there is no oxygen. Anaerobic micro organisms that do not require oxygen, decompose or break down complex compounds of the cow dung slurry. It takes a few days for the decomposition process to be complete and generate gases. The biogas is stored in the gas tank above the digester from which they are drawn through pipes for use.

Question 4.
What are the environmental consequences of using fossil fuels? Suggest the steps to minimise the pollution caused by various sources of energy including non conventional sources of energry.
Answer:
Fossil fuels have the following environmental effects:
(i) Air pollution: Burning of fossil fuels release oxides and sulphides in the air and many other harmful gases like carbon monoxide, sulphur dioxide, etc. These cause various health problems and also lead to acid rain which further affects water and soil resources.

(ii) Greenhouse effect: On burning fossil fuels, a large amount of carbon dioxide is released into the atmosphere. This is a greenhouse gas and does not allow the sun rays reflected from the earth surface to escape into the atmosphere. Thus, increasing the temperature of the atmosphere. This is called greenhouse effect which results in global warming.
Following steps can be taken to minimise pollution:

1. Use of smokeless appliances.
2. Use of refined technology to increase the efficiency of combustion process and to reduce escape of harmful gases into the atmosphere.
3. Judicious use of energy.

Question 5.
Differentiate between box-type solar cooker and spherical reflector type solar cooker.
Answer:

In this page, you can find CBSE Class 10 Science Chapter 11 Extra Questions and Answers Human Eye and Colourful World Pdf free download, NCERT Extra Questions for Class 10 Science will make your practice complete.

Class 10 Science Chapter 11 Extra Questions and Answers Human Eye and Colourful World

Extra Questions for Class 10 Science Chapter 11 Human Eye and Colourful World with Answers Solutions

Human Eye and Colourful World Extra Questions Very Short Answer Type

Question 1.
The ciliary muscles of a normal eye are in their
(i) most relaxed
(ii) most contracted state.
In which of the two cases is the focal length of the eye-lens more?
Answer:
In most relaxed state.

Question 2.
Write in one word or at the most in one sentence about the following:
(i) Mirrors used by dentists to examine teeth.
(ii) The smallest distance, at which the eye can see objects clearly without strain.
Answer:
(i) Concave mirror
(ii) Near point or 25 cm.

Question 3.
Which defect of the eye can be corrected by using a cylindrical lens?
Answer:
Astigmatism.

Question 4.
A person is advised to wear spectacles with concave lenses. What type of defect of vision is he suffering from?
Answer:
Near-sightedness/Short-sightedness/Myopia.

Question 5.
A person is advised to wear spectacles with convex lenses. What type of defect of vision is he suffering from?
Answer:
Far-sightedness/Long-sightedness/Hypermetropia.

Question 6.
What is colour blindness?
Answer:
Colour blindness is that defect of the eye due to which a person is unable to distinguish certain colours, sometimes even the primary colours.

Question 7.
When a monochromatic light having only one wavelength, passes through a prism, will it show dispersion?
Answer:
No, it will not show dispersion. It will only show deviation.

Question 8.
What do you understand by spectrum of white light?
Answer:
The band of seven colours formed on white screen when a beam of white light (or sunlight) is passed through a glass prism is called spectrum of white light.

Question 9.
The sun can be seen about two minutes before actual sunrise. Give reason.
Answer:
The sun can be seen about two minutes before actual sunrise because of atmospheric refraction.

Question 10.
Name the component of white light that deviates the least and the component that deviates the most while passing through a glass prism.
Answer:
Least deviated component: Red
Most deviated component: Violet

Question 11.
Why does the sky appear dark to astronauts?
Answer:
For scattering of light, particles are required. Since there are no particle in space, the sky appear dark to astronauts.

Human Eye and Colourful World Extra Questions Short Answer Type

Question 1.
What do you mean by power of accommodation of an eye?
Answer:
Power of Accommodation: The ability of an eye to focus the distant objects as well as the near by objects on the retina by changing the focal length is called power of accommodation.

Question 2.
What is colour-blindness? What kind of retinal cells are lacking in person suffering from this defect?
Answer:
The defect of the eye due to which a person is unable to distinguish between certain colours, is known as colour blindness. Cone-shaped retinal cells are responsible for making a person differentiate between colours. The colour blind persons do not possess cone cells that respond to certain colours.

Question 3.
Why there is no dispersion of light refracted through a rectangular glass slab?:
Answer:
After refraction at two parallel faces of a glass slab, a ray of light emerges in a direction parallel to the direction of incidence of white light. As rays of all colours emerge in the same direction, i.e., the direction of the incidence of white light, there is no dispersion. However, there is lateral displacement.

Question 4.
Why are ‘danger’ signal lights red in colour?
Answer:
Danger signal lights are red in colour because the red coloured light having longer wavelength is scattered the least by fog or smoke. Therefore, it can be seen clearly from a distance.

Question 5.
What is meant by dispersion of white light? Name the various colours of spectrum of white light in proper sequence.
Answer:
The splitting of white light into its component colours is called dispersion of light. The band of the coloured components formed due to dispersion of white light is called ‘spectrum’. Seven colours of spectrum are violet, indigo, blue, green, yellow, orange and red also known as ‘VIBGYOR’.

Question 6.
What is the cause of dispersion?
Answer:
All colours of light travel at the same speed in a vacuum. When these enter a transparent substance like prism, all slow down by different amounts depending on their wavelength. As these slow down by different amounts, different colours are refracted through different angles which causes dispersion.

Question 7.
Why do different rays deviate differently in the prism?
Answer:
Different wavelengths deviate differently in the prism because the angle of refraction for different colours having different wavelengths is different while passing through the glass prism.

Question 8.
How will you use two identical prisms so that a narrow beam of white light incident on one prism emerges out of the second prism as white light?
Answer:
By using two identical prism, one placed inverted with respect to the other we get a narrow beam of white lgiht incident on one prism emerges out of the second prism as white light.

Question 9.
What is presbyopia? What causes presbyopia? How is presbyopia corrected?
Answer:
The power of accommodation of the eye decreases with ageing. For most people, the near point gradually recedes and the far point comes closer. This defect is called presbyopia. It arises due to the gradual weakening of the ciliary muscles and diminishing flexibility of the eye lens. Such a person may suffer from myopia and hypermetropia.

This defect is then corrected by using bi-focal lenses of suitable focal lengths. The upper part of the lens is a concave lens which corrects myopia to see the distant objects clearly, while the lower part of the lens has convex lens which corrects the hypermetropia to see the nearby objects clearly.

Question 10.
What is astigmatism? What causes astigmatism? How is astigmatism corrected?
Answer:
In this defect, a person cannot focus on both horizontal as well as vertical lines at the same time. So he can see the objects clearly only in one plane.

This defect is mainly due to the cornea that is not perfectly spherical. As a result, the cornea has different curvatures in different directions of the horizontal and vertical planes. This defect can be corrected by using cylindrical lenses of suitable focal length and suitable axis in the spectacles.

Question 11.
What is meant by ‘persistence of vision’? We are able to see the movie picture in a cinema hall. How does this happen?
Answer:
The ability of the human eye to continue to see the image of an object for very short duration even after the removal of that object is called persistence of vision. In fact the sensation produced by the image of an object lasts for nearly 1/16th of a second on retina.

It is due to persistence of vision that we are able to see movie pictures in a cinema hall. The pictures in the form of a long film are projected on the screen at a rate of about 24 pictures per second. Under these conditions, the image of one picture persists on the retina of the eye till the image of the next picture falls on the screen, and so on. Due to this, the slightly different images of the successive pictures present on the film merge smoothly with one another and give us the feeling of continuity and moving images.

Question 12.
What is meant by scattering of light? Use this phenomenon to explain why the clear sky appears blue or the sun appears reddish at sunrise.
Answer:
The phenomenon in which a part of the light incident on a particle is redirected in different directions is called the scattering of light.

The blue colour of the sky is due to the scattering of sunlight by the molecules of the atmosphere. The light of shorter wavelength (blue) of the visible spectrum is scattered more than the light of longer wavelength by the atmospheric particles. When we look at the sky, the scattered light enters our eyes which majorly contains blue, colour and hence the sky appears blue.

At the time of sunrise and sunset, when the Sun is near the horizon, sunlight travels a greater distance through the atmosphere to reach us. During this, most of the shorter wavelengths present in it are scattered away from our line of sight by the molecules of air and other fine particles in the atmosphere. So, light reaching us directly from the rising or setting Sun consists mainly of the longer wavelength red colour because of which the Sun appears red.

Question 13.
Using the phenomenon of scattering of light, explain why there is a difference in the colour of the sun as it appears during sunrise and at noon.
Answer:
At sunrise, light from the sun near the horizon passes through thicker layers of air and larger distance in the earth’s atmosphere before reaching our eye. Hence shorter waves are scattered .. away and longer (red) waves reach our eye. Hence sun appears red.

However, at noon sunlight would travel relatively shorter distance only a little blue and violet colours are reflected and it is nearly the white light which reaches our eye.

Question 14.
Why does it take some time to see objects in a dim room when you enter the room from bright sunlight outside?
Answer:
In the bright sunlight, iris causes the pupil to become smaller so that only a small portion of light enters the eye and rods of the retina are also adjusted in the same way. But, when a person enters into a dimly lighted room, each iris takes some time to increase the diameter of the pupil, so that more amount of light can enter the eyes to see the object clearly and rod cells of the retina also take some time to adjust themselves to get the object in the dim light.

Question 15.
Explain giving a reason why the sky appears blue to an observer from the surface of the Earth. What should the appearance of the sky be during the day for an astronaut staying in the international space station orbiting the Earth? State reason to justify your answer.
Answer:
The fine particles in the atmosphere scatter light of shorter wavelength (blue colour) more strongly than the light of longer wavelength (red colour). Therefore, the sky appears blue from the surface of the Earth. For an astronaut, the sky would appear dark because in space there is no atmosphere to scatter light.

Question 16.
Why is the colour of sky blue?
Answer:
The molecules of air and other fine particles in the atmosphere have size smaller than the wavelength of visible light. These are more effective in scattering light of shorter wavelengths at the blue end than light of longer wavelengths at the red end. When sunlight passes through the atmosphere, the fine particles in air scatter the blue colour more strongly than red. The scattered blue light enters our eyes. Since we see the blue light from everywhere overhead, the sky appears blue.

Question 17.
What is Tyndall effect? Explain with an example.
Answer:
The scattering of light by particles in its path is called Tyndall effect. When a beam of light enters a smoke-filled dark room through a small hole, then its path becomes visible to us. The tiny dust particles present in the air of room scatter the beam of light all around the room. Thus, scattering of light makes the particles visible. Tyndall effect can also be observed when sunlight passes through a canopy of a dense forest. Here, tiny water droplets in the mist scatter light.

Question 18.
Describe the formation of rainbow in the sky with the help of a diagram.
Answer:

A rainbow is a natural spectrum appearing in the sky Raindrop after a rain. It is produced by dispersion of sunlight by tiny water droplets, present in the atmosphere. The water droplets act like small prisms. When a ray of light falls on water drop (or raindrop) it undergoes refraction and dispersion to form a spectrum. This spectrum undegoes internal reflection (inside the raindrop) and finally refracted again when it comes out of the raindrop. After the dispersion of light and internal reflections, the band of colours reaches observer’s eye in the form of a rainbow.
A rainbow is always formed in the direction opposite to that of the sun.

Question 19.
How does atmospheric refraction affect sunrise and sunset?
Or
What is meant by advance sunrise and delayed sunset. Draw a labelled diagram to explain.
Answer:

The layers of air nearer to earth are denser than those above it. At sunrise and sunset when the sun is below the horizon, the light rays starting from sun are incident on these layers. They pass through successively denser layers and thus get bent more and more towards the normal until they fall upon the eye of the observer O.

To the observer O these rays appear to come from B which is above horizon. It is for this reason that the sun is visible to us a little before it rises above the horizon and so also till a little later it sets below the horizon. The difference of time is about 2 minutes each for early rise and late setting of the Sun.

Question 20.
How does refraction of light take place in the atmosphere? Explain the reason why stars appear to twinkle and the planets do not twinkle.
Answer:
Since the atmosphere consists of varying densities the apparent position of the object, as seen through the hot air fluctuates. This wavering of light is an effect of atmospheric refraction.
The twinkling of a star is due to atmospheric refraction of starlight. The atmospheric refraction of light occurs in a medium of gradually changing refractive index.

The planets are much closer to the earth and are thus seen as extended sources. A planet is considered as a collection of large number of point sized sources of light, the total variation in the amount of light entering our eye from all individual point sized sources will average out to zero, thereby nullifying the twinkling effect.

Question 21.
A person needs a lens of power -4.5 D for correction of her vision.
(a) What kind of defect in vision is she suffering from?
(b) What is the focal length of the corrective lens?
(c) What is the nature of the corrective lens?
Answer:
(a) Myopia
(b)

(c) Concave lens

Question 22.
Write about power of accommodation of human eye. Explain why the image distance in the eye does not change when we change the distance of an object from the eye?
Answer:
Ability of the eye lens to focus nearby as well as distant objects on the retina by changing the curvature or focal length of the eye lens is known as power of accommodation.
lamge distance in the eye is the distance between the eye lens and the retina and it is fixed. As the object approaches from infinity towards the eye, the focal length of the eye lens decreases (or vice-versa) so as to maintain the same image distance.

Question 23.
How are we able to see nearby and also the distant objects clearly?
Answer:
This is due to the ability of the eye lens to adjust its focal length which is known as accommodation. When the cilary muscles are relaxed, the lens becoems thin. Thus, its focal length increases. This enables us to see distant objects clearly. When we are looking at objects closer to the eye, the ciliary muscles contract. This increases the curvature of the eye lens. The eye lens becomes thicker. The focal length of the eye lens decreases. This enables us to see nearby objects clearly.

Question 24.
Due to gradual weakening of ciliary muscles and diminishing flexibility of the eye lens a certain defect of vision arises. Write the name of this defect. Name the type of lens required by such persons to improve the vision. Explain the structure and function of such a lens.
Answer:
The name of the defect is Presbyopia. Bifocal lens is required to improve the vision.
In bifocal lens, upper portion is of concave or diverging lens to view far off objects and lower part is of convex or converging lens to view nearby objects.

Question 25.
With the help of ciliary muscles the human eye can change its curvature and thus alter the focal length of its lens. State the changes that occur in the curvature and focal length of the eye lens while viewing (a) a distance object, (b) nearby objects.
Explain, why a normal eye is not able to see distinctly the objects placed closer than 25 cm. without putting any strain on the eye.
Answer:
(a) Lens becomes thin
Curvature decreases.
Focal length increases.

(b) Curvature increrases.
Focal length decreases.
This is because focal length of the lens of a normal human eye cannot be decreased below certain limit i.e., 25 cm.

Human Eye and Colourful World Extra Questions Long Answer Type

Question 1.
State the functions of each of the following parts of the human eye:
(i) Cornea
(ii) Iris
(iii) Pupil
(iv) Retina
Millions of people of the developing countries are suffering from corneal blindness. This disease can be cured by replacing the defective cornea with the cornea of a donated eye. Your school has organised a campaign in the school and its neighbourhood in order to creat awareness about this fact and motivate people to donate their eyes after death. How can you along with your classmates contribute in this noble cause? State the objectives of organising such campaigns in schools.
Answer:

1. Cornea: Refraction of the light rays falling on the eye.
2. Iris: To control the size of the pupil.
3. Pupil: To regulate and control the amount of light entering the eye.
4. Retina: To act as a screen to obtain the image of object and generate electrical signals which are sent to the brain via optic nerves.

We can contribute by participating in different ways of motivating people for the noble cause of eye donation such as, street play, banners, poster, door to door campaign, etc.
Objectives of organising such campaigns:

1. To develop the habit of group work
2. To work for a common cause
3. To understand social issues and problems.

Question 2.
What is hypermetropia (far-sightedness)? Write two causes for development of this defect. Describe with a ray diagram how this defect of vision can be corrected by using spectacles.
Answer:
Hypermetropia (Long-sightedness): A person can see distant objects distinctly but cannot see nearby objects so clearly in this case, the image is formed behind the retina. This defect of the eye is hypermetropia.

Causes of hypermetropia: This defect arises because either:

1. the focal length of the eye lens is too long, or
2. the eyeball becomes too short, so that light rays from the nearby object, say at point N, cannot be brought to focus on the retina to give a distinct image.

Hypermetropia can be corrected by using convex lens of suitable focal length in spectacles.

Question 3.
(a) What is myopia? State the two causes of myopia. With the help of labelled ray diagrams show
(i) the eye defect myopia
(ii) correction of myopia using a lens.
(b)Why is the normal eye unable to focus on an object placed within 10 cm from the eye?
Answer:
(a) Myopia is the defect of the eye vision due to which a person can see the nearly objects clearly but cannot see the far objects so distinctly.
Causes of myopia: Myopia is caused:

• due to the elongation of the eyeball.
• due to decrease in the focal length of the eye lens.

Myopia can be corrected by using a concave lens of suitable focal length in the spectacles of such a person.

(b) The ability of the eye lens to adjust its focal length is called automatic accommodation. However, the focal length of the eye lens cannot be decreased below a certain limit. The maximum accommodation of a normal eye is reached when the object is at a distance of 25 cm from the eyes. Thus, the normal eye is unable to focus an object placed within 10 cm from the eye because it is beyond its power of accommodation.

Question 4.
(a) What is dispersion of white light? State its cause. Draw a ray diagram to show the dispersion of white light by a glass prism.
(b) A glass prism is able to produce a spectrum when white light passes through it but a glass slab does not produce any spectrum. Explain why it is so.
Or
State the cause of dispersion of white light by a glass prism. How did Newton, using two identical glass prisms, show that white light is made of seven colours? Draw a ray diagram to show the path of a narrow beam of white light, through a combination of two identical prisms arranged together in inverted position with respect to each other, when it is allowed to fall obliquely on one of the faces of the first prism of the combination.
Answer:
(a) The splitting up of white light into its constituent colours on passing through a refracting medium like a glass prism is called dispersion of light.
The dispersion of white light occurs because different colours of light bend through different angles with respect to the incident ray, as they pass through a prism. The red light bends the least while the violet the most as shown below.

(b) A glass slab acts as a combination of two identical glass prisms.

The second prism can be considered to be placed in an inverted position with respect to the first. The first prism splits the white light into its seven colour components. When these colour components fall on the second prism, it recombines them to form white light.

Human Eye and Colourful World Extra Questions Numerical Type

Question 1.
A person cannot see objects nearer than 75 cm from his eyes while a person with normal vision can see objects upto 25 cm from his eyes. Find the nature, the focal length and the power of the correcting lens used for the defective vision.
Solution:
The defect of the vision is hypermetropia.
Given, that u = – 25 cm and y = –75 cm,

The + sign with for the power indicates a convergent lens.

Question 2.
A person cannot see objects beyond 80 cm from his eye while a person with normal eyesight can see object easily placed upto 160 cm from the eye. Find the nature, the focal length and the power of the correcting lens.
Solution:
The defect of vision is myopia.

The -ve sign with f indicates the concave lens.

Question 3.
A person can see clearly only up to 3 metres. Prescribe a lens for spectacles so that he can see clearly up to 12 metres.
Solution:
Here, v= -3 m, u = -12 m, f = ?

A concave lens of focal length 4 m should be used.

Question 4.
A man with spectacles can read a book placed at 25 cm. The lens used in the spectacles has power – 2.0 D. The man without spectacles can read the book placed at which distance?
Solution:
Given: = -25 cm

In this page, you can find CBSE Class 10 Science Chapter 9 Extra Questions and Answers Heredity and Evolution Pdf free download, NCERT Extra Questions for Class 10 Science will make your practice complete.

Class 10 Science Chapter 9 Extra Questions and Answers Heredity and Evolution

Extra Questions for Class 10 Science Chapter 9 Heredity and Evolution with Answers Solutions

Heredity and Evolution Extra Questions Very Short Answer Type

Question 1.
What is meant by characteristics?
Answer:
It is the detail of appearance or behaviour; in other words, a particular form or a particular functions.
Example: Four limbs of human beings is a characteristic and that plant can perform photosynthesis is also a characteristic.

Question 2.
Who is known as the father of genetics?
Answer:
Gregor Johann Mendel is known as the father of genetics.

Question 3.
Define chromosome.
Answer:
Chromosome is a thread-like structure that bears genes and are enclosed within a nucleus. It is composed of DNA and protein.

Question 4.
Name the plant which was selected by Mendel for his experiments why he selected these plants?
Answer:
Mendel opted garden pea (Pisum satirum) to conduct his experiment.
Advantages of Selecting pea plant:

1. It is annual with short life cycle. So, several generations can be studied in short period.
2. It contains bisexual flowers, which are self pollinating.
3. It is easy to cross pollinate it.

Question 5.
Define a gene.
Answer:
Gene is a segment of a DNA molecule which carries the code for the synthesis of a specific protein.

Question 6.
Define alleles.
Answer:
Genes which code for a pair of contrasting traits are known as alleles, i.e., they are the different forms of the same gene.

Question 7.
Write the expanded form of DNA.
Answer:
Deoxyribonucleic acid.

Question 8.
Where is DNA found in a cell?
Answer:
DNA is found in genes or chromosomes.

Question 9.
What is the function of a gene?
Answer:
Gene is the carrier of the genetic information from one generation to the next.

Question 10.
Who proposed the theory of natural selection?
Answer:
Charles Darwin proposed the theory of natural selection.

Question 11.
Which of the following traits are recessive in pea plant? Dwarfness, violet flower, wrinkled seed.
Answer:
Dwarfness and wrinkled seeds are the recessive characters.

Question 12.
How many pairs of chromosomes are found in human beings?
Answer:
23 pairs of chromosomes are found in human beings.

Question 13.
In humans, the gene for black hair colour is B and gene for brown hair colour is b. What will be the hair colour of person having the genetic constitution?
(a) BB
(b) bb
(c) Bb
Answer:
(a) Black hair
(b) Brown hair
(c) Black hair (Heterozygous)

Question 14.
Write the names of two types of chromosomes found in an organism.
Answer:
Autosomes and sex chromosomes.

Question 15.
How many chromosomes are present in a sperm and an ovum?
Answer:
Sperm and ovum have 23 chromosomes each.

Question 16.
What is a sex chromosome?
Answer:
The chromosomes which are associated with sex determination of an organism are called sex chromosomes.

Question 17.
Which sex chromosomes are found in male and female human beings?
Answer:
Males have one X and one Y-chromosomes, whereas females have two X-chromosomes.

Question 18.
Who gave the theory of inheritance of acquired characters?
Answer:
Lamarck.

Question 19.
Define mutation.
Answer:
Sudden changes in the genetic form of an organism which are passed on to the next generation are called mutations. Mutations lead to variations in an organism.

Question 20.
What are fossils?
Answer:
Fossils are the remains or impressions of the dead animals and plants that lived in the past.

Question 21.
What is the significance of Archaeopteryx in evolution?
Answer:
Archaeopteryx provides evidence of evolution of birds from reptiles and its study shows that:

1. birds and reptiles had a common ancestor.
2. birds have evolved from reptiles.

Question 22.
Why are acquired characters not inheritable?
Answer:
Acquired characters are not inherited because they affect the somatic cells and these changes are not incorporated in the chromosomes of cells that will form germ cells.

Question 23.
What is genetic drift?
Answer:
The elimination of the genes of certain traits when a section of a species population migrates or dies due to natural calamity. It alters the gene frequency of the remaining population.

Question 24.
How do we know how old a fossil is?
Answer:
Age of fossils can be estimated by the depth of the layer of rocks in which they are found. Age of fossils can also be detected from the ratio of isotopes in the fossils containing rocks.

Question 25.
What is organic evolution?
Answer:
Evolution is the sequence of gradual changes of the living organisms, which takes place in the primitive organisms over millions of years resulting in the formation of new species.

Question 26.
What are the basic events in evolution?
Answer:
A gradual genetic change in a group of living beings to produce new forms brought about by changes in DNA during reproduction are the basic events in evolution.

Question 27.
When a cell reproduces, what happens to its DNA?
Answer:
When a cell reproduces, copy of DNA is created.

Question 28.
Newly formed DNA copies may not be identical at times. Give one reason.
Answer:
Newly formed DNA copies may not be identical at times if there is error or inaccuracies in DNA copying.

Question 29.
Why is variation important for a species?
Answer:
Variation is important for species to survive.

Heredity and Evolution Extra Questions Short Answer Type

Question 1.
Why offsprings differ from parents in certain characters?
Answer:
It is due to biparental percentage. The genes on chromosomes which pass over to the next generation is partly derived from both the parents (mother and father). During fertilisation of egg by the sperm, new combination of chromosomes enter the zygote, due to which certain variations occur in the offsprings. Thus, brothers and sisters show variations in their complexion habits and behaviour.

Question 2.
What are the causes of variations?
Answer:
Following are the causes of variations:

1. Dual percentage: Offsprings inherit some features from mother and some from father hence no offspring will exactly resemble to either of the parents or each other.
2. Mutation in gene or chromosomal pattern also causes variations.

Question 3.
Give the pair of contrasting traits of the following characters in pea plant and mention which is dominant and recessive
(i) yellow seed,
(ii) round seed
Answer:
(i). yellow – dominant
green – recessive
(ii) round – dominant
wrinkled – recessive

Question 4.
What is the contribution of Mendel to genetics?
Answer:
Mendel observed the occurrence of contrasting characters of garden pea in various generations. On this basis, he interpreted that these contrasting characters are controlled by factors. He considered each and every character as a unit, which is controlled by a ‘factor’. Factors are carriers of hereditary information. Now, factors are known as genes…

Question 5.
Do genetic combination of mothers play a significant role in determining the sex of a newborn?
Answer:
No, because mothers have a pair of X-chromosomes. All children will inherit an ‘X’ chromosome from their mother regardless of whether they are boys or girls.

Question 6.
How does use and disuse of an organ help in evolution of a new species?
Answer:
According to Lamarck, those organs which are used regularly become strong and more developed. On the other hand, those organs which are not used regularly become weak and degenerate. Such characters are inherited to the offsprings and so on. In the due course of time, such characters become permanent in later generations and become quite different from their ancestors, resulting in the formation of a new species.

Question 7.
A very small population of a species faces a greater threat of extinction than a larger population. Provide a suitable genetic explanation.
Answer:
Fewer individuals in a species impose extensive inbreeding among them. This limits the appearance of variations and puts the species at a disadvantage it there are changes in the environment. Since the individuals fail to cope up with the environmental changes, they may become extinct.

Question 8.
Does the occurrence of diversity of animals on earth suggest their diverse ancestry also? Discuss this point in the light of evolution.
Answer:
Though animals have a vast diversity in structures they probably do not have a common ancestry, because common ancestry may greatly limit the extent of diversity. As many of these diverse animals are inhabiting the same habitat, their evolution by geographical isolation and speciation is also not likely. Thus, a common ancestry for all the animals is not the likely theory.

Question 9.
All the human races like Africans, Asians, Europeans, Americans and others might have evolved from a common ancestor. Provide a few evidences in support of this view.
Answer:
All human races have evolved from a common ancestor because everybody has:

1. Common body design, structure, physiology and metabolism.
2. Constant chromosome number.
3. Common genetic blue print.
4. Freely inter-breeding species.

Question 10.
A change in DNA that is useful for one property to start with, can become useful later for a different function. Explain.
Answer:
A change/feature/property of an organism that may have helped in to adopt to an environmental condition can also become useful for a completely different function in the future. For example, feathers in birds, a character developed and selected during natural selection for providing insulation in cold weather, became useful in later stages for flight.
Some dinosaurs had feathers, but they could not fly. Birds later adapted the feathers to fly.

Question 11.
List two differences in tabular form between dominant trait and recessive trait. What percentage/proportion of the plants in the F, generation/progeny were round, in Mendel’s cross between round and wrinkled pea plants ?
Answer:

75% of the plants were with round seeds.

Question 12.
How many pairs of chromosomes are present in human beings? Out of these how many are sex chromosomes? How many types of sex chromosomes are found in human beings?
Answer:
23 pairs of chromosomes are present in human beings. One pair of these are sex chromosomes.
Two types of sex chromosomes are there:
XX and XY.

Question 13.
What is DNA copying? State its importance.
Answer:
A process where a DNA molecule produces two similar copies of itself in a reproducing cell is called DNA copying
Its importance are:

• It makes the transmission of characters from parents to the next generation possible.
• It causes variation in the population.

Question 14.
“We cannot pass on to our progeny the experiences and qualifications earned during our life time.” Justify the statement giving reason and examples.
Or With the help of two suitable examples, explain why certain experiences and traits earned by people during their lifetime are not passed on to their next generations. When can such traits be passed on?
Answer:
We acquire knowledge and skills in our lifetime such as learing dance, music, physical fitness, etc. But these skills cannot be passed to our progenies because:

1. Such characters or experiences acquired during one’s lifetime do not bring any change in the DNA of the germ cell.
2. Only germ cells are responsible for passing on the characters from the parents to the progemy. These traits can be passed to the next generation when the changes are in the DNA of the germ cell.

Question 15.
‘Different species use different strategies to determine sex of a newborn individual. It can be environmental cues or genetically determined’. Explain the statement by giving example for each strategy.
Answer:
Environmental cure: In some animals, the temperature at which fertilised eggs are kept determines whether the developing animal in egg is male or female. In some animals like snail, individual can change sex.
Genetic củe: A child who inherits an X chromosome from the father will be a girl and one who inherits a Y chromosome from the father will be a boy.:

Question 16.
List the two types of reproduction. Which one of the two is responsible for bringing in more variations in its progeny and how?
Answer:
The two types of reproduction are sexual reproduction and asexual reproduction. Sexual reproduction is responsible for bringing in more variations because of the process of DNA copying which may result in some error in it. Also, it involves fusion of male and female gametes from two different parents.

Question 17.
How do variations occur in an offspring?
Answer:
Dissimilarities between members of the same species is called variations. Two offsprings of the same parents show certain variations. Variations occur due to sex chromosomes. Variations arising in germplasm (genes) of the organism are heritable. Mother and father contribute to the gene pattern of the offsprings through their chromosomes, in which recombination occurs at the time of gametogenesis. In zygote formation, gene pattern of both parents come together, that causes some variations between parents and offsprings and amongst offsprings also.

Question 18.
Why is variation beneficial to the species but not necessary for the individual?
Answer:
The importance of variation in organism introduced during reproduction is that it helps the species of various organisms to survive and flourish even in adverse environment. If all the organisms of a population living in that habitat are exactly identical, then there is a danger that all of them may die and no one would survive under those conditions.

This will eliminate the species from the habitat completely. However, if some variations are present in some individual organism to tolerate excessive heat or cold, then ther is a chance for them to survive and flourish even in adverse excessive heat or cold. Thus, variation is useful for the survival of a species over time.

Question 19.
What is speciation ? List four factors responsible for speciation.
Answer:
Speciation is the formation of new species from the pre-existing population. Factors responsible for speciation:

1. Genetic drift
2. Natural selection
3. Geographical isolation
4. Mutation

Question 20.
List in tabular form, two distinguishing features between the acquired traits and the inherited traits with one example of each.
Or
List three distinguishing features, in tabular form, between acquired traits and the inherited traits.
Or
Distinguish between the acquired traits and the inherited traits in tabular form, giving one example for each
Or
Differentiate between inherited and acquired characters. Give one example for each type.
Answer:

Question 21.
In one of his experiments with pea plants Mendel observed that when a pure tall pea plant is crossed with a pure dwarf pea plant, in the first generation, F, only tall plants appear.
(a) What happens to the traits of the dwarf plants in this case ?
(b) When the F, generation plants were self-fertilised, he observed that in the plants of second generation, F, both tall plants and dwarf plants were present. Why it happened ? Explain briefly.
Answer:
(a) The dwarf traits of the plants is not expressed in the presence of the dominant tall trait.
(b) In the F, generation, both the tall and dwarf traits are present in the ratio of 3 : 1. This showed that the traits for tallness and dwarfness are present in the F, generation, but the dwarfness, being the recessive trait does not express itself in the presence of tallness, the dominant trait.

Question 22.
What do you mean by sex chromosomes ? Explain the process of sex-deter mination in man.
Answer:
Sex-Determination: A Person can have either a male sex or female sex, The process by which sex of a new born individual is determined is called sex-determination.

In human beings, there are 23 pairs of chromosomes, out of which 22 pairs are auto somes and one pair is Sex Chromosomes. A male has one x and one y chromosome and female has two X-chromosomes.

Question 23.
Mention the total number of chromosomes along with th sex chromosomes that are present in a human female and a human male. Explain how is sexually producing organisms the number of chromosomes in the progeny remains the same as that of the parents.
Answer:
Human male has 22 pairs of chromosomes along with XY sex chromosome. Human female has 22 pairs of chromosomes along with XX sex chromosomes.

The original number of chromosomes (the amount of DNA) becomes half during gamete formation. When the gametes fuse, the original number of chromosomes (the amount of DNA) is restored in the progeny.

Question 24.
“Two areas of study namely ‘evolution’ and ‘classification’ are interlinked”. Justify this statement.
Or
“Evolution and classification of organisms are interlinked.” Give reasons to justify this statement.
Answer:
Different forms of organisms have evolved during the course of evolution. Classification deals with grouping of these organisms into groups and subgroups based on their similarities and differences. The more characteristics any two species have in common more closely they are related. In other words, they will have a more recent ancestor.

Thus, classification helps is tracing the evolutionary relationships between the two organisms. Hence classification and evolution are interlinked.

Question 25.
Explain the following:
(a) Speciation,
(b) Natural Selection.
Answer:
(a) The process by which new species develop from the existing species is known as speciation. The factors which could lead to speciation are:
(i) Geographical isolation of population caused by various types of barriers such as mountain ranges, rivers and seas. This leads to reproductive isolation because of which there is no flow of genes between separated groups of the population.
(ii) Genetic drift caused by drastic changes in the frequencies of particular genes by chance. alone.
(iii) Variation caused in individuals because of natural selection.

(b) According to Darwin’s theory of natural selection, the individuals who are most suitable and fit are successful in struggle for existence for food, space, mate, etc. Their offsprings are also better developed and adapted to the environment. Whereas one who are less adapted to the environment may die. Thus, nature selects better-adapted organisms. This is called natural selection of the well-adapted, better-developed individuals of species.

Question 26.
“Natural selection and speciation leads to evolution.” Justify this statement.
Answer:
Natural selection is defined as the change in frequency of some genes in a population, which gives survival advantage to a species. Whereas speciation is the development of a new species from pre-existing ones.
This leads to a sequence of gradual change in the primitive organisms over millions of years, to form newer species which are very different from older ones. This is called evolution.

Question 27.
“Fossils are related to evolution”, justify this statement. Give the two ways by which age of the fossils can be estimated?
Answer:
Fossils are the remains of the organisms that once existed on earth, i.e., they are the preserved traces of living organisms. They provide evidence of evolution by revealing the characteristics of the past organisms and the changes that have occurred in these organisms to give rise to the present organisms.
Two ways of determining age of fossils are:

• Relative method – fossils closer to the surface are more recent.
• Datting-finding the ratio of different isotopes of the same element.

Question 28.
(i) “Planaria, insects, octopus and vertebrates all have eyes. Can we group eyes of these animals together to establish a common evolutionary origin? Justify your answer.
(ii) “Birds have evolved from reptiles”. State evidence to prove the statement.
Answer:
(i) No we can not group them together because the structure of the eye in each of the organisms is different.

(ii) Fossils of certain dinosaurs and reptiles show imprints of feathers along with their bones but they could not fly presumably, using the feathers for insulation only. Later they evolved and adapted feathers for flights, thus becoming the ancestors of present-day birds.

Question 29.
Mention three important features of fossils which help in the study of evolution.
Answer:

1. Fossils represent modes of preservation of ancient species.
2. Fossils help in establishing evolutionary traits among organisms and their ancestors.
3. Fossils help in establishing the time period in which organisms lived.

Question 30.
Explain analogous organs and homologous organs. Identify the analogous and homologous organs amongst the following:
Wings of an insect, wings of a bat, forelimbs of frog, forelimbs of a human.
Answer:
Analogous organs are those organs which have different structural designs and origin but perform similar functions.
Homologous organs are those which have the same basic structural design and origin but perform different functions.
Analogous organs: Wings of an insect, wings of a bat. Homologous organs: Forelimbs of a frog, forelimbs of a human.

Question 31.
Explain with the help of an example each, how the following provide evidences in favour of evolution:
(a) Homologous organs
(b) Analogous organs
(c) Fossils
Answer:
(a) Homologous organs. The study of these organs suggests that these organisms with organs having same structure but performing different functions have evolved from a common ancestor, e.g., forelimbs of different vertebrates.

(b) Analogous organs. The study of these apparently similar organs suggests that the organisms with apparently similar organs do not share common ancestory. Similarity in these organs is superficial or design and the structure of these organs are very different, e.g., Wings of bird and wings of butterfly.

(c) Fossils. They provide the missing link between the species, e.g., Fossils of dinosaurs with feathers or fossils of prehistoric horse, etc.

Question 32.
Describe the contribution of Lamarck.
Answer:
The gradual unfolding of organisms from pre-existing organisms through changes since the beginning of life is called evolution. The theory proposed by J. B. Lamarck is known as the theory of inheritance of acquired characters. According to this theory, the use and disuse of an organ leads to acquiring of change in that organ. These changes or variations can be passed on from one generation to the next but this idea of inheritance of acquired characters was soon discarded.

Question 33.
“It is possible that a trait is inherited but may not be expressed.” Give a suitable example to justify this statement.
Or
With the help of an example justify the following statement: “A trait may be inherited, but may not be expressed”.
Or
How did Mendel explain that it is possible that a trait is inherited but not expressed in an organism?
Answer:
Yes, it is possible that a trait is inherited but may not be expressed. For example, when pure tall pea plants are crossed with pure dwarf pea plants, only tall pea plants are obtained in F, generation. denle of F, but it did not express.

On selfing will plants of F, both tall and dwarf plants are obtained in F, generation in the ratio 3 : 1. Reappearance of the dwarf character, a recessive trait in F, generation shows that the dwarf trait was present in individuals of F, but it did not express.

Question 34.
How did Mendel’s experiments show that different traits are inherited independently? Explain.
Answer:
Mendel conducted a dihybrid cross; and observed that thought he started with two types of parents, he obtained four types of individuals in F. The appearance of new recombination in F, generations along with parental type characters show that traits are inherited undependently of each other.

Question 35.
Name two homologous structures in vertebrates. Why are they so called ? How do such organs help in understanding an evolutionary relationship?
Answer:
Two homologous structures in vetebrates are:

• limbs of birds and reptiles
• limbs of reptiles and amphibians.

These are called so because the organs have similar structure to perform different functions in various vertebrates.
The homologous characteristics of such organs indicate common ancestory. Thus these exist an evolutionary relationship.

Question 36.
List three factors that provide evidences in favour of evolution in organisms and state the role of each in brief.
Answer:
Three factors that provide evidences are:

1. Analogous organs-organisms with similar looking organs may have different origin.
2. Homologous organs-organisms with apparently different looking organs may have similar origin.
3. Fossils-allow us to make estimates of how far back evolutionary relationship go. Fossils when chronologically arranged help in tracing the evolutionary history of an organism.

Question 37.
Does geographical isolation of individuals of a species lead to formation of a new species. Provide a suitable explanation.
Answer:
Yes, geographical isolation gradually leads to genetic drift. This may impose limitations to sexual reproduction of the separated population. Slowly the separated individuals will reproduce among themselves and generate new variations. Continuous accumulation of those new variations through a few generations may ultimately lead to the formation of a new species.

Question 38.
What is an organic evolution ? It cannot be equated with progress. Explain with the help of a suitable example.
Answer:
Organic evolution is a sequence of gradual changes which take place in the organism over millions of years resulting in the formation of new organisms or species.

Evolution is not the progress from lower form of life to higher. It has given rise to more complex body design even while simpler body designs continue to flourish. For example, human beings who have not evolved from chimpanzees, but have common ancestors.

Question 39.
Give an example of the characteristics being used to determine how close two species are in evolutionary terms.
Answer:
Study of homologous organs such as forelimbs of mammals, birds, reptiles and amphibian shows that though they perform different functions but they have similar basic or internal structure. This is because they have evolved from common ancestor and help us in determining the closeness between two species in evolutionary terms.

Heredity and Evolution Extra Questions Long Answer Type

Question 1.
Explain with reason why giraffe has long neck.
Answer:
According to Lamarck’s theory of use and disuse, giraffes had to stretch their necks and forelimbs for feeding on leaves of tall trees because of which these organs were elongated. But this theory has been completely discarded. It is now proposed that, the giraffe’s neck evolved with time because of ‘necking’ battle with time and natural selection. Only giraffes with long necks survived.

Question 2.
Give the basic features of the mechanism of inheritance.
Answer:

1. Characteristics are controlled by genes.
2. Each gene controls one character.
3. There may be two or more forms of gene.
4. One form may be dominant over the other.
5. Genes are present on chromosomes.
6. An individual has to forms of gene whether similar or dissimilar.
7. The two forms separate from each other at the time of gamete formation.
8. The two forms are brought together in the zygote.

Question 3.
(i) Mention any two points of difference between acquired and inherited traits.
(ii) If the tail of a mouse is cut for twenty one generations, will the tail occur in the twenty second generation of that mouse ? Give reason to support your answer.
(iii) Define the term-natural selection,
Answer:
(i)

(ii) The mouse will continue to have information for presence of tail in its DNA. So, it will continue to have tail because absence of tail is an acquired trait and not an inherited trait.
(iii) Natural selection means that nature selects the best trait in a species, leading to survival of fittest and evolution of species.

Question 4.
In the following crosses write the characteristics of the progeny.

Answer:
(i) Round, yellow
(ii) Round, yellow
Round, green
Wrinkled, yellow
Wrinkled, green
(iii) Wrinkled, green
(iv) Round, yellow

Question 5.
How do Mendel’s experiments show that the
(i) traits may be dominant or recessive
(ii) traits are inherited independently?
Or
How do Mendel’s experiments show that
(a) traits may be dominant or recessive ?
(b) inheritance of two traits is independent of each other?
Answer:
(i) When Mendel cross-pollinated pure tall pea plants with pure dwarf pea plants, only tall plants were obtained in F generation. On self pollinating the F, progeny, both tall and dwarf plants appeared in F, generation in the ratio 3 : 1.

Appearance of tall character in both the F, and F, shows that it is a dominant character. The absence of dwarf character in F, generation and its reappearance in F, shows dwarfness is the recessive character.

(ii) When Mendel first crossed pure-breed pea plants having round-yellow seeds with pure breed pea plants having wrinkled-green seeds, he found that only round-yellow seeds were produced in the first-generation. No wrinkled-green seeds were obtained in the generation. From this, it was concluded that round shape and yellow colour of the seeds were dominant traits over the wrinkled shape and green colour of the seeds.

When the F, generation pea plants having round-yellow seeds were cross-bred by self-pollination, then four types of seeds having different combinations of shape and colour were obtained in second generation (F2). These were round-yellow, round-green, wrinkled-yellow and wrinkled green seeds. Such a cross is known as dihybrid cross as two sets of corresponding characters are considered.

Mendel observed that along with round-yellow and wrinkled-green, two new combinations of characteristics, round-green and wrinkled-yellow, had appeared in the F, generation. On the basis of this observation, Mendel concluded that though the two pairs of original characteristics (seed colour and shape) combine in the F generation, they get separated and behave independently in the subsequent generation.

Question 6.
What are the various evidences in favour of evolution?
Or
Explain with an example for each, how the following provides evidences in favour of evolution in organisms:
(i) Homologous organs
(ii) Analogous organs
(iii) Fossils
Or
List three factors that provide evidences in favour of evolution in organisms and state the role of each in brief.
Or
Explain the terms analogous and homologous organs with examples
Answer:
The following are the various evidences in favour of evolution:
(i) Homologous organs: Organs with a common basic structural design but with different functions are said to be homologous organ. For example, forelimbs of a frog, lizard, bird and man.
The forelimbs of man are used for grasping of lizard for running of frog for propping up and bird for flying. They have different functions but have same structural pattern.

(ii) Analogous organs: The analogous organs have different basic structure but perform similar functions. For example, the wing of insects and the wing of birds, have a totally different anatomy and origin but they perform the same function of flying of flying in air.

(iii) Evidences from fossils: The fossils also provide evidences for evolution. For example, the fossil Archaeopteryx looks like a bird but it bears a number of other features, which are found in reptiles. This observation provides a clue that birds have evolved from reptiles.

Question 7.
Explain the ways in which evolutionary relationships can be traced.
Answer:
Evolutionary relationships can be traced in the following ways:
(i) Study of homologous organs: Some organs in different organisms are similar in structure and design because they are inherited from a common ancestor. For example, forelimbs of horse, wings of bird and arms of man may be functionally different, but because of their similarity in structure, origin and design, they indicate that horse, birds and man are closely linked and had a common ancestor.

(ii) Study of fossils: Fossils are the remains or impressions of organisms that existed in the past, allow us to study organ structure of organisms that are no longer alive. Comparing their organ structure with organ structure of present-day organisms also enable us to trace evolutionary relationships.

(iii) Comparing DNA of different species: This will give us a direct estimate of how much the DNA has changed during the formation of these species. This, too, can be used as a criterion to trace evolutionary relationships.

Question 8.
Describe briefly various theories related with evolution.
Answer:
(A) Darwin’s Theory:
(i) Over-production: Every organism has enormous potential to reproduce.

(ii) Struggle for existance: Population size of an organism is limited due to struggle between the members of same species as well as the members of different species. It is due to struggle for food, space and mate.

(iii) Variation: Due to struggle, the fit organisms possess some variations which are favourable and they can leave the progeny to continue the favourable variations.

(iv) Survival of the fittest: The fittest organism survive to continue the favourable variations.
(v) Formation of a new species: These variations when accumulated for a long time, leads to the origin of a new species.

(B) Lemarck’s Theory: Lemarck proposed that the evolution of life forms had occurred by the use and disuse of organs.
He gave the example of Giraffes, which initially did not had long necks. But, in order to reach the leaves on tall trees, they adapted by elongation of their necks. Bypassing this acquired character to succeeding generations over the years they came to acquire long necks.

Question 9.
What are fossils? How are they formed? Describe in brief two methods of determining the age of fossils. State any one role of fossils in the study of the process of evolution.
Or
What are fossils? How are they formed? List two methods of determining the age of fossils. Explain in brief the importance of fossils in deciding the evolutionary relationships.
Answer:
Fossils are dead remains of animals and plants from remote past.
Fossils are formed when dead organisms are not completely decomposed. The organisms may get trapped in resins of the tree, lava of volcanoes or hot mud, which when hardens retains the animal’s parts thus forming fossils. . Two methods of determining the age of fossils are:

1. Relative method: By estimating the age of the layer of earth’s crust where the fossils is found. Fossils near the surface are recent and those in the deeper layers are more ancient.
2. Radiocarbon dating method: By detecting the ratios of different isotopes of carbon in the fossils.

Fossils play the following roles:

1. By determining the age of fossils we come to know the type of earth strata present at that time.
2. We can also know the type of animals and plants present on the earth at that time.
3. They help in establishing evolutionary relationship by providing connecting links.

Question 10.
What is speciation? List four factors that could lead to speciation. Which of these cannot be a major factor in the speciation of a self-pollinating plant species? Explain. Give reason to justify your answer.
Answer:
Speciation is the formation of new species from the pre-existing population.
Factors responsible for speciation:

1. Genetic drift
2. Natural selection
3. Geographical isolation
4. Mutation

Geographical isolation cannot be a major factor in the speciation of a self-pollinating plant species because physical barrier cannot be created in self-pollinating plants.

Question 11.
How has the method of artificial selection’ by humans helped in the evolution of different vegetables?
Answer:
A wild variety of a plant may show different variations. Humans have selected some such variants and grown them for generations and during the course of time, they have become totally different species.
For example, variants in wild cabbage were selected on the basis of certain features to generate different vegetables.

1. Short distances between leaves, led to formation of green leaf buds-the common cabbage.
2. Arrested flower development has bred broccoli.
3. The variant with sterile flowers has made the cauliflower.
4. Variant with swollen leaf parts-kohlrabi.
5. Variant with larger leaves kale.

Question 12.
What are Mendel’s laws? Explain them with suitable diagram.
Answer:
Mendel’s Laws: The three major laws of inheritance proposed by Mendel are as follows:
(i) Law of Dominance (First Law): This law states that when two alternative forms of a trait or character (gene or alleles) are present in an organism only dominant trait expresses it self in F, progency. This law has its basis from the monohybrid Cross.

(ii) Law of Segregation or Law of Purity of Gametes (Second Law): This law states that when a pair of contrasting characters are brought together in hybrid union, the two charac ters stay together without mixing and separate or segregate from each other when the hybrid forms gametes. The gametes are always pure for a particular character because a gamete may carry either the dominat or the recessive character but not both because it is a haploid structure. So this law is also called ‘Law of purity of gametes’.

(iii) Law of Independent assortment (Third Law): This law states that, two factors of each character assort or separate out independent of the factors of other characters at the time of gamete formation and get randomly rearranged in the offsprings.

In this page, you can find CBSE Class 10 Science Chapter 7 Extra Questions and Answers Control and Coordination Pdf free download, NCERT Extra Questions for Class 10 Science will make your practice complete.

Class 10 Science Chapter 7 Extra Questions and Answers Control and Coordination

Extra Questions for Class 10 Science Chapter 7 Control and Coordination with Answers Solutions

Control and Coordination Extra Questions Very Short Answer Type

Question 1.
Mention the receptors for light and sound in animals.
Answer:
Sense organs are called receptors. The receptor of light in animals is calld photoreceptor. The receptor of sound in animals is called phonoreceptor.

Question 2.
Which hormone regulates the concentration of sugar in the blood?
Answer:
Insulin secreted by Islets of Langerhans of pancreas.

Question 3.
Define ‘reflex action.’
Answer:
Reflex action is a rapid, automatic response to a stimulus which is not under the voluntary control of the brain.

Question 4.
Name few involuntary actions controlled by the hindbrain.
Answer:
Involuntary actions controlled by hindbrain are vomiting, salivation and blood pressure.

Question 5.
What is an axon?
Answer:
It is a large, single, unbranched nerve fibre arising from the cyton. It carries impulses from cyton located in CNS to effectors.

Question 6.
Why are roots called positively geotropic?
Answer:
This is because the roots always grow towards the gravity of the Earth.

Question 7.
What is the number of cranial nerves and spinal nerves in human beings?
Answer:
There are 12 pairs of cranial nerves and 31 pairs of spinal nerves in human beings.

Question 8.
Name the largest cell present in the human body.’
Answer:
Neuron.

Question 9.
Which part of central nervous system controls reflexes?
Answer:
Spinal cord.

Question 10.
Name the part of neuron
(i) Where information is acquired.
(ii) Through which information travels as an electrical impulse.
Answer:
(i) Dendrite,
(ii) Axon.

Question 11.
What will happen if intake of iodine in our diet is low?
Answer:

• When iodine intake is low, release of thyroxine from thyroid gland will be less by which protein, carbohydrate and fat metabolisms will be affected.
• A person might suffer from goitre in case of iodine deficiency in the body.

Question 12.
Which hormone controls the metabolism of calcium and phosphorus in human beings?
Answer:
Parathyroid hormone (parathormone).

Question 13.
Name the hormone, the secretion of which is responsible for dramatic changes in appearance in girls and boys when they approach 10-12 years of age.
Answer:
Oestrogen from the ovaries of girls and testosterone from testes of boys.

Question 14.
Name two tissues that provide control and coordination in multicellular animals.
Answer:
The two tissues that provide control and coordination in multicellular animals are nervous tissue and muscular tissue.

Question 15.
Draw a well labelled diagram of Neuron cell.
Answer:
Neuron cell is shown in the following diagram.

Question 16.
What do you understand by the sleep movement of plant organs?
Answer:
Sleep movement in plants e.g., in flowers is to protect the reproductive organs from the cold. Hence, sepals and petals of saffron flower close at sunset and open up in the morning.

Question 17.
State the main function of abscistic acid in plants. Answer: Abscisic acid slows plant growth and inhibits division of cells.’ Question 18. What is spinal cord? Which body function is controlled by it? (U. P. 2018)
Answer:
Spinal cord is a long and cylindrical tube which is present in vertebral column. From its dorsal and ventral horn sensory and motor nerves originate which form spinal nerve. At the centre it contains neurocoel. Spinal cord is covered externally by three membranes. In this, H shaped grey matter is filled, which is surrounded by white matter. Lateral and dorsal sides have horns.
Spinal cord: It serves as principal centre for almost all the reflexes and involuntary activities. It provide conduction pathway for nerves to transmit stimuli to brain.

Control and Coordination Extra Questions Short Answer Type

Question 1.
Define a synapse.
Answer:
Synapse is a very fine gap between telodendria of axon of one neuron and dendrites of another neuron. These two structures do not unite with each other but remain separated by a fine gap.

Question 2.
Mention the functions of forebrain.
Answer:
The forebrain performs the following functions:

• It is responsible for intelligence, memory, consciousness, will power and voluntary actions.
• It has the centres for visual reception, hearing reception, touch, smell and temperature reception.

Question 3.
Answer the following:

1. Which hormone is responsible for the changes noticed in females at puberty?
2. Dwarfism results due to deficiency of which hormone?
3. Blood sugar level rises due to deficiency of which hormone?
4. Iodine is necessary for the synthesis of which hormone?

Answer:

1. Oestrogen
2. Growth hormone
3. Insulin
4. Thyroxine

Question 4.
Name the hormones responsible for regulation of

1. metabolism of carbohydrates, fats and proteins
2. balance of calcium and phosphate
3. blood pressure
4. water and electrolyte balance.

Answer:

1. Thyroxine
2. Parathormone
3. Adrenaline
4. Vasopressin.

Question 5.
What is a tropic movement? Explain with an example.
Answer:
The directional growth movement of plants due to external stimuli is called a tropic movement. It can be either towards the stimulus, or away from it. For example, in case of phototropic movement, shoots respond by bending towards light while roots respond by bending away from it.

Question 6.
Why Mimosa pudica (touch-me-not) leaves droop down when touched?
Answer:
It is due to turgor pressure difference between the upper and lower halves of the base of petiole (pulvinus). Lower half cells lose water and upper half cells of pulvinus become turgid due to transfer of water from lower cells. Thus, the entire leaf droops down when touched.

Question 7.
Why are the electrical-chemical signals not an efficient means of communication in plants?
Answer:
Unlike animals, where there is a nervous system for conduction of nerve impulses and circulatory system for conduction of hormones, there are no specialised tissues in plants. So, the electrical chemical signals are not an effective means of communication in plants.

Question 8.
If a ripened fruit is kept in a basket of raw fruits, then what will happen? What causes it?
Answer:
The ripened fruit will release ethylene (hormone) which causes ripening of other raw. fruits kept in a basket.

Question 9.
What is cerebrospinal fluid? What is its function? .
Answer:
Cerebrospinal fluid is the fluid found in the cavities of brain and central canal of spinal cord and in between arachnoid and pia mater.
Function: It prevents the brain and spinal cord from mechanical shocks.

Question 10.
Answer the following:

1. Name the endocrine gland associated with a brain.
2. Which gland secretes digestive enzymes as well as hormones?
3. Name the endocrine gland associated with kidneys.
4. Which endocrine gland is present in males but not in females?

Answer:

1. Pituitary
2. Pancreas
3. Adrenal
4. Testes.

Question 11.
Describe the advantage of division of human heart in right and left parts.
Answer:
The advantage of division of human heart in right and left parts is that it prevents mixing of oxygenated and deoxygenated blood.

Question 12.
How do animal muscles move?
Answer:
The nerve fibrés at the end of a neuron are attached to muscles. This area is called neuro-muscular junction. When nerve impulses are conducted to this area, the special proteins present in the muscle cells change their shape and arrangement in the cell in response to nervous electrical impulses. New arrangement of these proteins give the muscle cells a shorter form thus bringing about movement of muscles.

Question 13.
What is turgor movement?
Answer:
Turgor movement is the movement due to the difference of turgidity of the cells in the lower half and upper half of pulvinus (petiole of leaf). When leaf of touch-me-not plant (Mimosa pudica) is touched, the electrical signal send chemical signals from leaflets to pulvinus (petiole) of leaf. Cells in the lower half of pulvinus lose water and become flaccid, while cells in the upper half of pulvinus become turgid due to accumulation of more water. Hence, leaf droops down for a short time.

Question 14.
Why do tendrils coil around hard rough objects?
Answer:
The growth movement of tendril in response to unilateral stimulus of touch is called thigmotropism. Tendrils of louki, tori, karela, and sweet pea plants coil around hard objects when they come in their contact. It occurs due to unequal growth of two sides of a tendril. The growth of the surface which comes in contact of the support is retarded, while it remains normal or increased on the other side, due to which tendril coils around the support.

Question 15.
How are involuntary actions and reflex actions different from each other?
Answer:

Question 16.
Nervous and hormonal system together perform the function of control and coordination in human beings. Justify the statement.
Answer:
Nervous and hormonal system together perform the function of control and coordination in human beings. Let us take an example, in the case of any emergency, stimulus is being perceived by CNS (Central nervous system). The stimulus is analysed and the response is sent to the effectors. Simultaneously, sympathetic nerves stimulate adrenal gland to release adrenaline which regulates blood pressure, increases heartbeat, constricts blood vessels and dilates pupil, etc. So, both nervous and endocrine systems interact and overcome the crisis together.

Question 17.
How are the brain and spinal cord protected?
Answer:
(i) Brain: It is protected by the bony box called cranium. It is also called as skull. Also the membranes that surround the brain (meninges) are filled with cerebrospinal fluid that act as shock absorbers protecting the brain.
(ii) Spinal cord: The vertebral column, commonly called backbone, protects the spinal cord.

Question 18.
What are ductless glands?
Answer:
These ductless glands which form a group of tissues or cells in acting at distant sites of the body known as target organ or target cell.

Question 19.
Name the hormone secreted by thyroid gland and describe its main functions.
Answer:
The glands which secrete hormones directly into blood are called ductless or endocrine glands. They reach their target cells through blood only and not through any duct. Thyroid gland is a bilobed structure situated at posterior surface of larynx. Its structure resembles ‘H’. Its weight in humans is about 25-30 g.

It mainly releases thyroxine or thyroid hormone which is a product of iodine. This hormone regulates metabolic activities in body. Its functions are to control the BMR rate, protein synthesis, increase heartbeat rate, uses of glucose. Lack of thyroid causes slowing of heartbeat, weak immune system and brain damage.

Question 20.
What are hormones and enzymes? Mention any two differences between them.
Answer:
The differences between hormones and enzymes are as follows:

Control and Coordination Extra Questions Long Answer Type

Question 1.
Which hormone is released into the blood when its sugar level rises? Name the organ which produces the hormone and describe its effect on blood sugar level. Also name one digestive enzyme that this organ secretes and the function of this enzyme.
Answer:
Hormone: Hormones are released by stimulated cells are diffuse all around the original cell. Insulin hormone is released into the blood when its sugar level rises. Pancreas secretes the insulin hormone. The function of insulin hormone is to lower the blood sugar level.

Deficiency of insulin hormone in the body causes a disease known as diabetes. Diabetes is characterised by large quantities of sugar in the blood. The insulin hormone controls the metabolism of sugar. If due to some reason pancreas does not produce and secrete sufficient amount of insulin into blood.

then the sugar level in the blood rises. The high sugar level in the blood can cause many harmful effects to the body of person. The person having severe diabetes are treated by giving injection of insulin.

The pancreas secretes pancreatic juice which contains enzymes like trypsin for digesting proteins, lipase for breakdown of emulsified fats and amylase for breakdown of starch.

Question 2.
Differentiate between tropic and nastic movements in plants.
Answer:

Question 3.
(i) What are cranial and spinal nerves? Describe a spinal nerve. (ii) Draw a diagram of the human brain and label the following parts: (a) Cerebrum (b) Meninges (c) Medulla oblongata (d) Cerebellum
Answer:
(i) Cranial nerves are the nerves associated with the brain. These are 12 pairs in number and carries both sensory and motor nerves. Spinal nerves are the nerves connected with the spinal cord. These are 31 pairs in number. Spinal nerve arises in the form of dorsal root and ventral root and both unite in the neural canal to form a single branch. It comes out of the vertebral column through intervertebral canal and then divides into dorsal, ventral and visceral branches.

(ii)

Question 4.
Describe the central nervous system in human beings.
or
How many parts of brain are there? Sodden reactions like blood pressure, saliva secretion and vomating are controlled by which parts?
Answer:
The central nervous system in human beings consists of brain and spinal cord.
(i) Brain: Brain is the highest coordinating centre in the body. It is covered by meaninges, which is made up of three layers. It is protected by cranium. Brain is broadly divided into:

(a) Forebrain: The forebrain includes cerebrum and olfactory lobes. Cerebrum is the largest part of the brain. It consists of two cerebral hemispheres. Sensory and motor receptors are present in the brain. There are various regions for reception of vision (occipital lobe), reception of sound (temporal lobe), touch, smell, temperature (parietal lobe) and muscular activities (frontal lobe). Olfactory lobes are one in pair and receives olfactory nerves.

(b) Midbrain: It is the small portion of the brian that connects cerebrum with the other parts of the brain and spinal cord.

(c) Hindbrain: It consists of cerebellum, pons and medulla oblongata. Cerebellum is responsible for coordination and adjustment of movement and posture. Pons regulate respiration. Medulla oblongata regulates swallowing, coughing, sneezing and vomitting…

(ii) Spinal cord: Medulla oblongata extends downwards, enclosed in vertebral column to form a cylindrical structure known as spinal cord. It is also covered by meninges. It is the reflex centre of the body.

Question 5.
Give the various functions performed by the plant hormones.
Or
Name various plant hormones. Also give their physiological effects on plant growth and development.
Answer:
The various functions performed by the plant hormones are:
(i) Auxins promote cell enlargement and cell differentiation. They also promote growth.

(ii) Gibberellins promote cell enlargement and cell differentiation in the presence of auxin. It also help in breaking the dormancy in seeds and buds. It promote the growth in fruits.

(iii) Cytokinins promote cell division and help in breaking the dormancy of seeds and buds. It delay the ageing in leaves. It promotes the opening of stomata and also fruit growth.

(iv) Abscisic acid promotes the dormancy in seeds and buds. It promotes the closing of stomata and falling of leaves. It also inhibits growth, reverses the growth promoting effects of auxins and gibberellins. Its effects include wilting of leaves.

(v) Ethylene promotes the falling of leaves, ripening of fruits and helps in breaking bud dormancy.

Question 6.
What is reflex action? Explain with the help of examples.
Or
What are reflex actions? Give two examples. Explain a reflex are.
Answer:
A reflex action is defined as a spontaneous, automatic and mechanical response to a stimuli without the will of an individual. In such actions there is no involvement of the brain. All reflex actions are conveyed through the spinal cord by a path called reflex arc.
The reflex action travels in the following sequence:

The reflex arc consitute the following components:

1. A receptor to perceive the stimulus.
2. A sensory or afferent nerve which carries the message from the receptor to the spinal cord.
3. The neurons of spinal cord transmit the impulse from afferent neurons to efferent neurons.
4. The motor or efferent nerve carries messages from spinal cord to the muscles (effectors) that show the response.

Some examples of reflex actions are:

1. Blinking of eyes when a foreign particle gets in them.
2. Sneezing if an unwanted particle enters the nose.
3. Watering of mouth at the sight or smell of good food.
4. Withdrawl of foot if a nail comes in the way while walking and pricks the foot.
5. Immediate withdrawl of hand on touching some hot thing.

Question 7.
With the help of an activity demonstrate geotropism in plants.
Answer:

1. Soak some seeds of gram or moong in water for one day.
2. Pierce slightly big holes (2 mm diameter) at the bottom of the cup.
3. Fill it with 1 cm. thick layer of garden soil.
4. Sprinkle soaked seeds (moong / gram) over the soil. Water the seeds.
5. Put the cup on 2 pieces of wooden or stone slabs so that there is a little gap between the top of the table and bottom of the cup.
6. Cover the lower part of the set-up with black paper.
7. Water the seeds regularly with little water.
8. You will observe that the roots come out from the holes and grow towards the Earth showing positive geotropism.

Question 8.
Draw a well-labelled diagram of human brain and explain the functions of various parts.
Answer:
Structure and functions of human brain: It is the most important and delicate portion of the body. In an adult, its weight is 1300-1400 g. It remains enclosed in bony case called cranium. The brain is covered with three meninges. The outer meninx is called duramater and inner one is piamater.

In between these two arachnoid matter is present. A dense network of blood capillaries present in these meninges, which provide food and oxygen to the brain. In between the meninges, the space is filled with cerebrospinal fluid (80%) which protects the brain against external shocks and mechanical injury.

1. Forebrain: The brain is divided into three parts-olfactory lobes, cerebrum and diencephalon. Cerebrum is the largest part of the brain. It is highly folded and convoluted which increases the surface area. The outer part of cerebrum is made up of grey matter while inner is made up of white matter. Cerebrum controls various activities of the body.
Parts of Forebrain

• Olfactory lobes: These are concerned with sense of smell.
• Cerebrum: It is the centre of instinct thinking, memorising, reasoning, consciousness, learning, etc.
• Diencephalon: It is the centre of involuntary actions such as hunger, thirst, sleep, temperature, control, metabolism, etc.

2. Midbrain: It connect forebrain to hindbrains, many involuntary actions like change in size of pupil and auditory impulses are controlled by it.

3. Hindbrain: It consists of cerebellum, medulla oblongata and pons varolii.
(i) Pons varolii: It is situated just below of cerebral peduncles like a lobe of 2.5 cm long. It provides control of activities like mastication, salivation, lacrimation and movement of eyeballs, etc.
(ii) Cerebellum: It controls the body posture and equilibrium. It controls and coordinates the movement of voluntary muscles.
(iii) Medulla oblongata: It is the posterior’most part of the brain which is cylindrical in shape. It controls involuntary activities such as respiration, heartbeat, circulation etc.

Question 9.
What do you know about reflex action? Explain with the help of diagram. What is the importance of reflex actions?
Answer:
Reflex action The path followed by information or impulse in reflex action is called reflex arc. It is formed in the spinal cord and consists of two neurons:

• Sensory neurons containing dorsal horn.
• Motor neurons containing ventral horn.

Sensory nerves pick up impulses from sense organs and bring them to spinal cord. As a result of which motor nerves take the message from spinal cord to the concerned effector orgAnswer: This response is called reflex action and this pathway is called reflex arc.

Importance: Reflex actions are very important, which have the following importances:

• These are controlled by spinal cord and thus, minimise the burden on brain.
• These are very fast and accurate, wich minimise chances of mishappening.

Some examples of reflex actions:

• Sneezing: During this, the air from the lungs comes out forcefully.
• Coughing: When food particles enter the windpipe the air from the lungs comes out forcefully.

We have compiled NCERT MCQ Questions for Class 12 English Vistas Chapter 8 Memories of Childhood with Answers Pdf free download. MCQ Questions for Class 12 English with Answers were prepared according to the latest question paper pattern. Practicing these Memories of Childhood Class 12 English MCQs Questions with Answers really effective to improve your basics and learn all the key concepts.

MCQ Questions for Class 12 English Vistas Chapter 8 Memories of Childhood with Answers

Question 1.
Annan’s words for Bama had
(a) deep impression on her
(b) no effect on her
(c) made her laugh
(d) made her cry

Answer

Answer: (a) deep impression on her

---

Question 2.
Bama’s brother was asked by the landlord’s men
(a) his name and street
(b) his address only
(c) his parents’ names
(d) his caste

Answer

Answer: (a) his name and street

---

Question 3.
He used to get his books from
(a) neighbour’s house
(b) from his teacher
(c) from a library
(d) from the city

Answer

Answer: (c) from a library

---

Question 4.
The author on learning about the practice of Untouchability was
(a) amused
(b) terribly sad
(c) happy
(d) very guilty

Answer

Answer: (b) terribly sad

---

Question 5.
On reaching home, Bama narrated the incident to her
(a) elder sister
(b) cousin
(c) father
(d) elder brother

Answer

Answer: (d) elder brother

---

Question 6.
The elderly man, Bama saw, was carrying a small packet and this made her
(a) want to cry
(b) dance
(c) want to sing
(d) want to shriek with laughter

Answer

Answer: (d) want to shriek with laughter

---

Question 7.
Which tree had its fruit occasionally blown down by the wind?
(a) almond tree
(b) apple tree
(c) mango tree
(d) Jamun tree

Answer

Answer: (a) almond tree

---

Question 8.
The author enlists numerous things that pulled her to
(a) eat on the roadside
(b) a standstill
(c) take a side on the joy-riders
(d) watch the snake charmer only

Answer

Answer: (b) a standstill

---

Question 9.
The distance from school to her home usually took Bama
(a) ten minutes
(b) thirty minutes to an hour
(c) forty minutes
(d) one hour

Answer

Answer: (b) thirty minutes to an hour

---

Question 10.
Bama’s incident took place when she was in
(a) class two
(b) class three
(c) class five
(d) class nine

Answer

Answer: (b) class three

---

Question 11.
The author, when she heard that her hair was to be cut hid
(a) under the bed
(b) behind the door
(c) in the bathroom
(d) in the attic

Answer

Answer: (a) under the bed

---

Question 12.
Shingled hair was worn by
(a) cowards
(b) warriors
(c) young girls
(d) dancers

Answer

Answer: (a) cowards

---

Question 13.
The author’s mother had taught her that the hair of the following people were shingled by the enemy
(a) skilled guns men
(b) labourers
(c) unskilled warriors
(d) generals of the army

Answer

Answer: (c) unskilled warriors

---

Question 14.
Everyone present in the dining room started eating when the bell rang
(a) once
(b) twice
(c) thrice
(d) four times

Answer

Answer: (c) thrice

---

Question 15.
As the author pulled out her chair
(a) the other student snatched it
(b) she slipped into it from one side
(c) the others clapped
(d) the other pupils made fun of her

Answer

Answer: (b) she slipped into it from one side

---

Question 16.
The small girls wore
(a) shorts
(b) tunics
(c) frocks
(d) sleeved aprons

Answer

Answer: (d) sleeved aprons

---

Question 17.
The line of girls in which the author was placed, were marching into the
(a) study room
(b) playgrounds
(c) kitchen
(d) dining room

Answer

Answer: (d) dining room

---

Question 18.
Zitkala’s experience started with her being
(a) handcuffed
(b) tied to a chair
(c) tied with chains to a bedpost
(d) tied to a table

Answer

Answer: (b) tied to a chair

---

Question 19.
Zitkala-Sa’s real name was
(a) Pearl S. Buck
(b) Tishani Doshi
(c) Gertrude Simmons Bonnin
(d) Hillary

Answer

Answer: (c) Gertrude Simmons Bonnin

---

Question 20.
The first account is by an
(a) Irish woman
(b) Indian woman
(c) Australian woman
(d) American woman

Answer

Answer: (d) American woman

---

Question 21.
What had hurt Bama in the society?
(a) Political plays
(b) class students
(c) Road shows
(d) Practice of untouchability

Answer

Answer: (d) Practice of untouchability

---

Question 22.
What is Belfry?
(a) part of a bell tower
(b) part of a tower
(c) part of a music tower
(d) part of a silver tower

Answer

Answer: (a) part of a bell tower

---

Question 23.
What did the story showcase?
(a) Discrimination on the basis of casteism specially with Indians in western culture
(b) difference of Indian and Western culture
(c) views of minorities
(d) none

Answer

Answer: (a) Discrimination on the basis of casteism specially with Indians in western culture

---

Question 24.
How did the scene in the market change Bama’s life?
(a) because of that she decided to study hard and stand against discrimination
(b) she became fearful
(c) she became stubborn
(d) she was irritated

Answer

Answer: (a) because of that she decided to study hard and stand against discrimination

---

Question 25.
Why did Zitkala start crying at the dining table ?
(a) she didn’t like the food
(b) she was a stranger
(c) because of eating by formula
(d) all these

Answer

Answer: (c) because of eating by formula

---

Question 26.
Why was Zitkala in tears on her first day in the land of apples?
(a) because of new environment
(b) cultural differences
(c) eating by formula and cutting of her hair
(d) all these

Answer

Answer: (d) all these

---

Question 27.
How did Bama earn respect of the people of higher class?
(a) by shopping
(b) by spending money
(c) by studying hard and earning first position in her class
(d) all these

Answer

Answer: (c) by studying hard and earning first position in her class

---

Question 28.
“I felt like sinking to the floors” why did Zitkala feel so?
(a) because her blanket was stripped off from her shoulders and she felt uncomfortable
(b) because she didn’t like her short hair
(c) because she didn’t like her dress
(d) because she felt cold

Answer

Answer: (a) because her blanket was stripped off from her shoulders and she felt uncomfortable

---

Question 29.
When did Bama first come to know of social discrimination?
(a) in class 1
(b) when she was in class 3
(c) when she was in class 2
(d) when she was in class 4

Answer

Answer: (b) when she was in class 3

---

Question 30.
What attracted Bama in the street?
(a) monkeys
(b) the cyclist
(c) Pongal offerings
(d) all these

Answer

Answer: (d) all these

---

Question 31.
What is the meaning of untouchability?
(a) segregating a minority from the mainstream social group
(b) not to touch anyone
(c) keep distance from
(d) none

Answer

Answer: (a) segregating a minority from the mainstream social group

---

Question 32.
What comic incident did Bama mention to her brother?
(a) a man bringing vadas for his landlord by holding the vada packet by a string.
(b) a man bringing vadas in a basket
(c) a man bringing vadas in a tiffin
(d) all these

Answer

Answer: (a) a man bringing vadas for his landlord by holding the vada packet by a string.

---

Question 33.
Why did Zitkala not like her hair cut?
(a) because her mother told her that mourners and cowards keep such hair.
(b) she liked long hair
(c) she wanted different style
(d) she didn’t like anyone to touch her hair

Answer

Answer: (a) because her mother told her that mourners and cowards keep such hair.

---

Question 34.
What did Annan tell Bama?
(a) Education is the only way to break the chains of caste system
(b) running away is the only way out to solve the problem
(c) keeping quiet is the only way to solve the issue
(d) none

Answer

Answer: (a) Education is the only way to break the chains of caste system

---

Question 35.
What did Zitkala Sa feel when her long hair was cut?
(a) oppression and victimization
(b) happy and delighted
(c) relaxed
(d) None

Answer

Answer: (a) oppression and victimization

---

Question 36.
What is the meaning of childhood memories?
(a) memories with a child
(b) memories of the times spent with a child
(c) memories of olden times
(d) memories formed during childhood period

Answer

Answer: (d) memories formed during childhood period

---

Question 37.
Who is Bama’s brother?
(a) A boy
(b) A young boy
(c) Annan
(d) None

Answer

Answer: (c) Annan

---

Question 38.
What did Zitkala Sa find?
(a) discrimination against native American culture and women
(b) her dignity was in danger
(c) women were in danger
(d) all these

Answer

Answer: (a) discrimination against native American culture and women

Question 39.
What advice did Annan give to Bama?
(a) to go away from the place
(b) to leave the house
(c) to study hard and progress to rise above all shackels of indignity
(d) All

Answer

Answer: (c) to study hard and progress to rise above all shackels of indignity

---

Question 40.
What does the story present?
(a) An autobiography of the author
(b) An autobiography of a man
(c) An autobiographical episode from the lives of two women
(d) None

Answer

Answer: (c) An autobiographical episode from the lives of two women

---

We hope the given NCERT MCQ Questions for Class 12 English Vistas Chapter 8 Memories of Childhood with Answers Pdf free download will definitely yield fruitful results. If you have any queries related to CBSE Class 12 English Memories of Childhood MCQs Multiple Choice Questions with Answers, drop your questions below and will get back to you in no time.

We have compiled NCERT MCQ Questions for Class 12 English Vistas Chapter 3 Journey to the End of the Earth with Answers Pdf free download. MCQ Questions for Class 12 English with Answers were prepared according to the latest question paper pattern. Practicing these Journey to the End of the Earth Class 12 English MCQs Questions with Answers really effective to improve your basics and learn all the key concepts.

MCQ Questions for Class 12 English Vistas Chapter 3 Journey to the End of the Earth with Answers

Question 1.
Name the program which aimed to take high school students to the end of the world?
(a) The author’s delight
(b) Geoff Green’s ‘Students on Ice’ programme
(c) Teachers delight
(d) School program

Answer

Answer: (b) Geoff Green’s ‘Students on Ice’ programme

---

Question 2.
What is the aim of The Journey to, Antarctica?
(a) to know the geography more closely
(b) world tour
(c) to sensitize the young minds towards climatic change
(d) to see the beauty of the earth

Answer

Answer: (c) to sensitize the young minds towards climatic change

---

Question 3.
The lesson Journey to the end of the Earth revolve around_______
(a) children and their tour
(b) tourism
(c) It revolves around the world
(d) world’s most preserved place, Antarctica

Answer

Answer: (d) world’s most preserved place, Antarctica

---

Question 4.
The study of our past is possible in Antarctica through_________.
(a) Half-million-year-old carbon records trapped in its layers of ice
(b) Cordilleran folds
(c) pre-Cambrian granite shields
(d) All of the above

Answer

Answer: (d) All of the above

---

Question 5.
When do you know that the threat of global warming is very real?
(a) when you see the seals on ice floes
(b) when you see the austral light
(c) When you see glaciers retreating and ice shelves collapsing
(d) All of the above

Answer

Answer: (c) When you see glaciers retreating and ice shelves collapsing

---

Question 6.
What caused disturbance to the silence of the continent?
(a) the humans
(b) Avalanches
(c) The birds
(d) the animals

Answer

Answer: (b) Avalanches

---

Question 7.
‘And for humans, the prognosis isn’t good.’ This line means__________.
(a) The future of mankind is not promising.
(b) The future of mankind is secure.
(c) The prognosis isn’t good enough to be relied upon.
(d) The future of human kind is encouraging.

Answer

Answer: (a) The future of mankind is not promising.

---

Question 8.
What is the figure of speech used in the line, “It’s like walking into a giant ping-pong ball”?
(a) Metaphor
(b) Alliteration
(c) Pun
(d) Simile

Answer

Answer: (d) Simile

---

Question 9.
The author’s first emotion on facing Antarctica’s expansive white landscape was ____________.
(a) wonder
(b) relief
(c) shock
(d) disbelief

Answer

Answer: (b) relief

---

Question 10.
Antarctica has been described as ___________.
(a) coldest, driest, windiest
(b) hottest and inhabitable
(c) thriving with all sorts of life
(d) All of the above

Answer

Answer: (a) coldest, driest, windiest

---

Question 11.
If we want to know our earth, the human race and its past, present, and future where should we go?
(a) Northern Pole
(b) Southern Pole
(c) Gondwana
(d) Antarctica Continent

Answer

Answer: (d) Antarctica Continent

---

Question 12.
How does the geographical phenomena help us?
(a) how small changes cause big things to happen
(b) it makes us study
(c) it helps us to watch everything closely
(d) none

Answer

Answer: (a) how small changes cause big things to happen

---

Question 13.
Which program was a life changing program?
(a) Tour and Travels
(b) Know Antarctica
(c) Know your earth
(d) Students on Ice

Answer

Answer: (d) Students on Ice

---

Question 14.
Where is the world’s geological history trapped?
(a) on southern pole
(b) On Northern Pole
(c) on Asia Continent
(d) On Antarctica Continent

Answer

Answer: (d) On Antarctica Continent

---

Question 15.
Where does 90% of earth’s total ice exist?
(a) Pacific region
(b) Southern oceans
(c) Northern pole
(d) Antarctica Continent

Answer

Answer: (d) Antarctica Continent

---

Question 16.
How old are the records trapped in the layers of ice on Antarctica?
(a) 1 million year old
(b) 2 million years old
(c) half million-year-old carbon records
(d) All these

Answer

Answer: (c) half million-year-old carbon records

---

Question 17.
What are the reasons of increasing global temperatures?
(a) cutting of trees
(b) human activities
(c) increasing pollution
(d) All these

Answer

Answer: (d) All these

---

Question 18.
What does the author compare the running and stretching of crabs to?
(a) to melting glaciers
(b) to avalanches
(c) to stray dogs
(d) None

Answer

Answer: (c) to stray dogs

---

Question 19.
What is phytoplankton?
(a) Oceans
(b) Southern oceans
(c) Microscopic grasses
(d) None

Answer

Answer: (c) Microscopic grasses

---

Question 20.
Why was the programme ‘Students on Ice ‘ a great success?
(a) because of its arrangements
(b) good travel facilities
(c) good food arrangements
(d) because of the life changing exposure to the youngsters

Answer

Answer: (d) because of the life changing exposure to the youngsters

---

Question 21.
What were the writer’s feelings on reaching the continent?
(a) of relief and amazement
(b) tired and fatigued
(c) sad
(d) none

Answer

Answer: (a) of relief and amazement

---

Question 22.
What are the important indications of the future of human kind?
(a) melting glaciers
(b) depleting ozone layer
(c) increasing global warming
(d) All these

Answer

Answer: (d) All these

---

Question 23.
What wondered Tishani Doshi?
(a) Beauty of the place
(b) white expanse
(c) Beauty of balance on the earth
(d) None

Answer

Answer: (c) Beauty of balance on the earth

---

Question 24.
How many years back were India and Antarctica part of the same landmass?
(a) 100 million years back
(b) 300 million years ago
(c) 200 million years ago
(d) 400 million years ago

Answer

Answer: (b) 300 million years ago

---

Question 25.
Why is Antarctica a restricted place?
(a) because it’s too cold
(b) because of no life
(c) because of snow
(d) to protect the environment

Answer

Answer: (d) to protect the environment

---

Question 26.
Why did the author visit Antarctica?
(a) to have a better understanding of the planet
(b) to see the white expanse
(c) to enjoy the cold weather
(d) none

Answer

Answer: (a) to have a better understanding of the planet

---

Question 27.
Why did Geoff decide to take high school students on the journey?
(a) to make them tour the world
(b) to make them enjoy
(c) to make them feel relaxed
(d) to make them understand their planet and respect it.

Answer

Answer: (d) to make them understand their planet and respect it.

---

Question 28.
What is there in Antarctica?
(a) man’s history
(b) snow’s history
(c) geographical history
(d) Geological history

Answer

Answer: (d) Geological history

---

Question 29.
How will the geographical phenomena help us to know the history of mankind?
(a) by telling the age of existence of human beings on the earth
(b) by showing the global warming
(c) by showing the imapacts of global warming
(d) none

Answer

Answer: (a) by telling the age of existence of human beings on the earth

---

Question 30.
What does the lesson revolve around?
(a) It revolves around the world
(b) tourism
(c) children and their tour
(d) the world’s most preserved place, Antarctica

Answer

Answer: (d) the world’s most preserved place, Antarctica

---

We hope the given NCERT MCQ Questions for Class 12 English Vistas Chapter 3 Journey to the End of the Earth with Answers Pdf free download will definitely yield fruitful results. If you have any queries related to CBSE Class 12 English Journey to the End of the Earth MCQs Multiple Choice Questions with Answers, drop your questions below and will get back to you in no time.

We have compiled NCERT MCQ Questions for Class 12 English Flamingo Poem 5 A Roadside Stand with Answers Pdf free download. MCQ Questions for Class 12 English with Answers were prepared according to the latest question paper pattern. Practicing these A Roadside Stand Class 12 English MCQs Questions with Answers really effective to improve your basics and learn all the key concepts.

MCQ Questions for Class 12 English Flamingo Poem 5 A Roadside Stand with Answers

Question 1.
What is the open prayer from near the open window?
(a) For money to fall from the sky
(b) for more number of people to stop
(c) for getting money from the government
(d) for the sound of coming cars to stop at the road stand to help the owner to earn money from them

Answer

Answer: (d) for the sound of coming cars to stop at the road stand to help the owner to earn money from them

---

Question 2.
What does I stand for in the poem?
(a) owner of the stand
(b) city flower who stopped on the stand
(c) Poet of the poem-Robert Frost
(d) None

Answer

Answer: (c) Poet of the poem-Robert Frost

---

Question 3.
Who are the ‘pitiful kin’ in the poem?
(a) social agencies
(b) government officials
(c) city people with cars
(d) The poor rural folk and farmers

Answer

Answer: (d) The poor rural folk and farmers

---

Question 4.
Who went and waited in the lines?
(a) The rural folk to hear the government’s declaration
(b) The rural folk to talk to the social agencies
(c) The rural folk to have a word with the government officials
(d) The rural folk went to hear the sound of stopping cars

Answer

Answer: (d) The rural folk went to hear the sound of stopping cars

---

Question 5.
Who made roadside stand and where?
(a) The sarpanch made in the village
(b) The government made in the village
(c) social agencies made in the village
(d) The poor rural people made in the village

Answer

Answer: (d) The poor rural people made in the village

---

Question 6.
Who do selfish cars refer to?
(a) social agencies
(b) Government officials
(c) city people
(d) car owners who do not stop on the stand

Answer

Answer: (d) car owners who do not stop on the stand

---

Question 7.
Which word in the poem means fading?
(a) quarts
(b) relief
(c) relief
(d) withering

Answer

Answer: (d) withering

---

Question 8.
What is the importance of cash flow for city people?
(a) they love it
(b) they earn it with their hard work
(c) they earn by befooling others
(d) it runs their life so it is their life line

Answer

Answer: (d) it runs their life so it is their life line

---

Question 9.
What does ‘Out of their wit’ mean in the poem?
(a) by helping the poor people
(b) by showing rosy pictures to the poor people
(c) by fooling and exploiting the poor people to their own benefit
(d) all these

Answer

Answer: (c) by fooling and exploiting the poor people to their own benefit

---

Question 10.
What does polished traffic refer to?
(a) city people
(b) smartness of city people
(c) insensitive attitude of city people and their gentle appearance
(d) none

Answer

Answer: (c) insensitive attitude of city people and their gentle appearance

---

Question 11.
What promise was the government making to relocate the villagers?
(a) to give them all the luxuries
(b) to show them movies
(c) their all needs will be looked after
(d) all these

Answer

Answer: (c) their all needs will be looked after

---

Question 12.
How do city people harm the poor rural folk?
(a) by misguiding and depriving them of their sleep
(b) by attracting them
(c) by making false promises
(d) none

Answer

Answer: (a) by misguiding and depriving them of their sleep

---

Question 13.
Who are beasts of prey in the poem?
(a) the government officials
(b) Rural folk
(c) The city folk
(d) All these

Answer

Answer: (c) The city folk

---

Question 14.
Why are the city people called greedy?
(a) Because of their appearance
(b) because they did not stop at the stand
(c) because of their behavior
(d) because of their selfish interests

Answer

Answer: (d) because of their selfish interests

---

Question 15.
Which words in the poem show that the poet was feeling hurt over the poor plight of rural folk?
(a) sometimes I feel I can hardly bear
(b) The thought of so much childish longing in vain
(c) I can’t help owning the great relief it would be To put these people at one stroke out of their pain
(d) All these

Answer

Answer: (d) All these

---

Question 16.
What is the childish longing that the poet refers to?
(a) to travel the city malls
(b) to travel the city showrooms
(c) to interact with city people
(d) hope of getting some financial help from the polished city traffic

Answer

Answer: (d) hope of getting some financial help from the polished city traffic

---

Question 17.
What do the flowers of cities in a roadside stand refer to?
(a) city people
(b) city cars
(c) urban crowd
(d) The pleasures of cities

Answer

Answer: (d) The pleasures of cities

---

Question 18.
What is a Roadside Stand in the poem?
(a) a bus stop
(b) a waiting point
(c) a shed outside a roadside old house
(d) none

Answer

Answer: (c) a shed outside a roadside old house

---

Question 19.
What does Frost present in the poem A Roadside Stand?
(a) the lives of poor deprived people with understanding and in a sympathetic way
(b) the lives of people who stand on bus stand
(c) lives of travellers
(d) none

Answer

Answer: (a) the lives of poor deprived people with understanding and in a sympathetic way

---

Question 20.
Who is Robert Frost?
(a) An American storyteller
(b) An American essayist
(c) An American narrator
(d) An American twentieth century poet

Answer

Answer: (d) An American twentieth century poet

---

We hope the given NCERT MCQ Questions for Class 12 English Flamingo Poem 5 A Roadside Stand with Answers Pdf free download will definitely yield fruitful results. If you have any queries related to CBSE Class 12 English Poem A Roadside Stand MCQs Multiple Choice Questions with Answers, drop your questions below and will get back to you in no time.

We have compiled NCERT MCQ Questions for Class 12 English Flamingo Chapter 6 Poets and Pancakes with Answers Pdf free download. MCQ Questions for Class 12 English with Answers were prepared according to the latest question paper pattern. Practicing these Poets and Pancakes Class 12 English MCQs Questions with Answers really effective to improve your basics and learn all the key concepts.

MCQ Questions for Class 12 English Flamingo Chapter 6 Poets and Pancakes with Answers

Question 1.
What does the expression ‘made to look ugly’ refer to ?
(a) make up done to look presentable before camera
(b) faces made by actors
(c) faces nade by office boy
(d) arrangements in the make up room

Answer

Answer: (a) make up done to look presentable before camera

---

Question 2.
What does the expression ‘ fiery misery’ mean?
(a) the glow of lights
(b) the bright lights
(c) the bright colorful dresses of heroines
(d) discomfort to the actors in the makeup room

Answer

Answer: (d) discomfort to the actors in the makeup room

---

Question 3.
What things attracted the audience in the plays staged by MRA?
(a) their jewellery
(b) their make up
(c) their dialogues
(d) their sets and costumes

Answer

Answer: (d) their sets and costumes

---

Question 4.
How many people were there in MRA group?
(a) 150
(b) 180
(c) 140
(d) 200 people from 20 nationalities

Answer

Answer: (d) 200 people from 20 nationalities

---

Question 5.
Why was Subbu termed as ‘many sided genius’?
(a) his flattery
(b) gossip style
(c) interaction with others
(d) ability to create and manage things

Answer

Answer: (d) ability to create and manage things

---

Question 6.
Why was the office boy disappointed with his job in Gemini studios?
(a) because of his behavior
(b) because of his boss
(c) because of his intimacy with boss
(d) because of his inability to be a star

Answer

Answer: (d) because of his inability to be a star

---

Question 7.
Why was author’s work appeared nothing at Gemini?
(a) Because of no direct relation to filmmaking
(b) because of cutting- pasting
(c) because he sits idle
(d) because he does nothing

Answer

Answer: (a) Because of no direct relation to filmmaking

---

Question 8.
How was the Gemini studio influenced by the plays staged by MRA?
(a) They imitated their styles
(b) They imitated their dialogues
(c) They imitated their story
(d) They imitated their sets and costumes

Answer

Answer: (d) They imitated their sets and costumes

---

Question 9.
Which plays were presented by MRA in Madras?
(a) Macbeth
(b) Othello
(c) A doll’s house
(d) Jetham Valley and The Forgotten Factors

Answer

Answer: (d) Jetham Valley and The Forgotten Factors

---

Question 10.
What qualities was Subbu admired for ?
(a) acting, writing filmmaking skills and the management skills
(b) acting and writing
(c) flattery
(d) gossips

Answer

Answer: (a) acting, writing filmmaking skills and the management skills

---

Question 11.
Who was Subbu’s enemy?
(a) no one
(b) the author
(c) actors
(d) The boy in the makeup room

Answer

Answer: (d) The boy in the makeup room

---

Question 12.
Why did the office boy in the makeup room come to the author?
(a) because he was unemployed
(b) because of his interest in literary arts and film making
(c) to earn money
(d) to do makeup

Answer

Answer: (b) because of his interest in literary arts and film making

---

Question 13.
Why was MRA invited to Gemini studio?
(a) To show their play
(b) Because of political affiliations
(c) because of political infuence
(d) none

Answer

Answer: (b) Because of political affiliations

---

Question 14.
Why did he visit the studio?
(a) to deliver a speech
(b) to gossip with the workers
(c) to check the workers
(d) to know the film making

Answer

Answer: (a) to deliver a speech

---

Question 15.
Why is the Englishman’s visit referred as unexplained mystery?
(a) because of his appearance
(b) because of his dress
(c) because of his hairstyle
(d) because of his unfamiliarity and baffled looks

Answer

Answer: (d) because of his unfamiliarity and baffled looks

---

Question 16.
What has been the make up room compared to?
(a) make up company
(b) a Parlour
(c) a jewellery shop
(d) hair-cutting salon

Answer

Answer: (d) hair-cutting salon

---

Question 17.
What does he bring to the notice of readers through this write up?
(a) movies and different roles
(b) heroines and their tantrums
(c) heroines and make up
(d) Independent India and its infancy

Answer

Answer: (d) Independent India and its infancy

---

Question 18.
What was Asokamitran’s job in the studio?
(a) to arrange pancakes
(b) to arrange make up kits
(c) to serve water
(d) cut out newspaper clippings on a wide variety of subjects and store them in files.

Answer

Answer: (d) cut out newspaper clippings on a wide variety of subjects and store them in files.

---

Question 19.
What was the brand name of the make up material that Gemini studio bought?
(a) Pancake
(b) Mancake
(c) Fancake
(d) latin cake

Answer

Answer: (a) Pancake

---

Question 20.
What does his book “My Years with Boss” talk of ?
(a) his job
(b) explain the nature of his boss
(c) explains his environment
(d) impact of movies on every aspect of life in India.

Answer

Answer: (d) impact of movies on every aspect of life in India.

---

We hope the given NCERT MCQ Questions for Class 12 English Flamingo Chapter 6 Poets and Pancakes with Answers Pdf free download will definitely yield fruitful results. If you have any queries related to CBSE Class 12 English Poets and Pancakes MCQs Multiple Choice Questions with Answers, drop your questions below and will get back to you in no time.

We have compiled NCERT MCQ Questions for Class 12 English Flamingo Chapter 7 The Interview with Answers Pdf free download. MCQ Questions for Class 12 English with Answers were prepared according to the latest question paper pattern. Practicing these The Interview Class 12 English MCQs Questions with Answers really effective to improve your basics and learn all the key concepts.

MCQ Questions for Class 12 English Flamingo Chapter 7 The Interview with Answers

Question 1.
What kind of a novel was The Name of The Rose?
(a) hilarious
(b) fiction
(c) non-fiction
(d) a serious one

Answer

Answer: (d) a serious one

---

Question 2.
In what way interviews have become a commom place of journalism?
(a) because of its power, influence and medium of communication
(b) because of its pomp
(c) because of its glory
(d) because of its rapport

Answer

Answer: (a) because of its power, influence and medium of communication

---

Question 3.
Who has written Alice in Wonderland?
(a) Christopher
(b) Mukand
(c) Rudyard Kripling
(d) Lewis Caroll

Answer

Answer: (d) Lewis Caroll

---

Question 4.
Why does Eco call the success of his book a mystery?
(a) because of its success
(b) because of its popularity
(c) because of many factors
(d) because of many factors and many other books were written on the same medieval period

Answer

Answer: (d) because of many factors and many other books were written on the same medieval period

---

Question 5.
According to Umberto what will happen to the world if we eliminate empty spaces from the universe?
(a) The world will become beautiful
(b) The world will be completely ours
(c) The world will shrink and will become as big as a fish.
(d) The world will be round

Answer

Answer: (c) The world will shrink and will become as big as a fish.

---

Question 6.
What ideas do you form of Umberto’s personality after his interview with Mukand?
(a) a very rigid person
(b) a boastful and arrogant
(c) an illusionary vision
(d) an academician with philosophical and ethical interest

Answer

Answer: (d) an academician with philosophical and ethical interest

---

Question 7.
How many scholarly works are to his credit?
(a) more than 5
(b) more than10
(c) more than 20
(d) more than 40

Answer

Answer: (d) more than 40

---

Question 8.
While interview being interviewed by Mukand, Umberto speaks about his philosophy and novel, What does he point out at ?
(a) he loves writing
(b) he loves to be in spotlight
(c) at the universe and its workings
(d) at empty spaces in the universe- Interstices

Answer

Answer: (d) at empty spaces in the universe- Interstices

---

Question 9.
What impression is formed of Umberto after reading the lesson- The Interview?
(a) A person of substance
(b) a person of character
(c) a person of words
(d) A person of vision and firm convictions

Answer

Answer: (d) A person of vision and firm convictions

---

Question 10.
What is an interview?
(a) a medium of talking to the people
(b) a medium to spread rumours
(c) a medium to be the talk of the town
(d) a medium of interaction and introspection

Answer

Answer: (d) a medium of interaction and introspection

---

Question 11.
What does writing novels on Sundays signify?
(a) writing novels- his passion
(b) writing novels- his need
(c) writing novels- his casual job
(d) writing novels- his interest

Answer

Answer: (c) writing novels- his casual job

---

Question 12.
What in today’s world our main source of information?
(a) social media
(b) newspapers
(c) short screens
(d) Interviews and interactions

Answer

Answer: (d) Interviews and interactions

---

Question 13.
What is the primitive view about being photographed?
(a) person’s soul is stolen
(b) part of personality is lost
(c) person can be commanded
(d) All these

Answer

Answer: (d) All these

---

Question 14.
What days did he used to write novels?
(a) Saturday night
(b) Friday night
(c) every evening
(d) Sundays

Answer

Answer: (d) Sundays

---

Question 15.
At what age was Eco’s book published?
(a) at the age of 20
(b) at the age of 25
(c) at the age of 22
(d) at the age of 26

Answer

Answer: (c) at the age of 22

---

Question 16.
What are some of the positive traits of interviews?
(a) brings out the truth and gives vivid impression of contemporaries
(b) helps finding hidden talents
(c) useful medium of communication
(d) All these

Answer

Answer: (d) All these

---

Question 17.
What was distinctive (special) about Eco’s academic writing style?
(a) His realistic narrative style with trial and errors
(b) his interrogative style
(c) his monotonous unrealistic style
(d) fictitious imaginative style

Answer

Answer: (a) His realistic narrative style with trial and errors

---

Question 18.
According to an old saying what happens when perceptions are made about a person?
(a) Person feels happy
(b) person becomes popular
(c) Person feels irritated
(d) The original identity of his soul is lost

Answer

Answer: (d) The original identity of his soul is lost

---

Question 19.
The excerpt -The Interview has been taken from which book?
(a) Christopher’s introduction to The Penguin Book of Interviews
(b) Features for Vanity Fair
(c) The name of the Rose
(d) none

Answer

Answer: (a) Christopher’s introduction to The Penguin Book of Interviews

---

Question 20.
What does V.S. Naipaul feel about interviews?
(a) horror
(b) happy
(c) wounded
(d) none

Answer

Answer: (c) wounded

---

We hope the given NCERT MCQ Questions for Class 12 English Flamingo Chapter 7 The Interview with Answers Pdf free download will definitely yield fruitful results. If you have any queries related to CBSE Class 12 English The Interview MCQs Multiple Choice Questions with Answers, drop your questions below and will get back to you in no time.

We have compiled NCERT MCQ Questions for Class 12 English Flamingo Chapter 8 Going Places with Answers Pdf free download. MCQ Questions for Class 12 English with Answers were prepared according to the latest question paper pattern. Practicing these Going Places Class 12 English MCQs Questions with Answers really effective to improve your basics and learn all the key concepts.

MCQ Questions for Class 12 English Flamingo Chapter 8 Going Places with Answers

Question 1.
The second time Sophie asked for an autograph from Danny, he did not again have
(a) a piece of paper
(b) a pen
(c) a pencil
(d) a sketch pen

Answer

Answer: (b) a pen

---

Question 2.
After leaving the bench on the park, who did Sophie think she met?
(a) Danny’s parents
(b) her own parents
(c) her brother
(d) Danny Casey

Answer

Answer: (d) Danny Casey

---

Question 3.
What became a hard burden to carry?
(a) her sadness
(b) her worry
(c) her studies
(d) her creative skills

Answer

Answer: (a) her sadness

---

Question 4.
Sophie had a truly
(a) wild imagination
(b) bad nature
(c) arrogant mannerism
(d) casual attitude

Answer

Answer: (a) wild imagination

---

Question 5.
Sophie went to meet Danny by the
(a) side of the canal
(b) river bank
(c) jetty
(d) harbour

Answer

Answer: (a) side of the canal

---

Question 6.
Sophie’s reaction when Jansie questioned her about Danny was that
(a) she was happy
(b) she was angry with Geoff for letting out her secret
(c) she wanted Jansie to meet Danny
(d) she wanted Jansie to tell all their friends

Answer

Answer: (b) she was angry with Geoff for letting out her secret

---

Question 7.
Little Derek remarked on the way back that
(a) Ireland will win the World Cup
(b) Danny Casey is a bad player
(c) Geoff should also play football
(d) Derek wanted to be a soccer player himself

Answer

Answer: (a) Ireland will win the World Cup

---

Question 8.
Casey, in the match, scored the
(a) first goal
(b) second goal
(c) third goal
(d) fourth goal

Answer

Answer: (b) second goal

---

Question 9.
Sophie wished that Geoff would care more about his
(a) friends and relatives
(b) friends and acquaintances
(c) his clothes
(d) his parents

Answer

Answer: (c) his clothes

---

Question 10.
Danny and Sophie had stood in front of Royce’s window and talked about
(a) footwear
(b) sunglasses
(c) clothes
(d) movies

Answer

Answer: (c) clothes

---

Question 11.
Three photographs were seen on the wall of
(a) Sophie’s room
(b) Janie’s room
(c) Geoffs room
(d) father’s room

Answer

Answer: (c) Geoffs room

---

Question 12.
The father was optimistic about
(a) Danny being successful
(b) Danny being thrown out of the team as he was a bad player
(c) Danny scoring maximum goals
(d) Danny being awarded a gold medal

Answer

Answer: (a) Danny being successful

---

Question 13.
Sophie and Geoff’s father, when told by Geoff that Sophie had met Danny, reacted with
(a) anger
(b) loud scream
(c) expression of disdain
(d) a slap on Sophie’s face

Answer

Answer: (c) expression of disdain

---

Question 14.
Sophie told Geoff that she had met Danny at __
(a) the football ground
(b) at the doctor’s clinic
(c) at the arcade
(d) at the pastry shop

Answer

Answer: (c) at the arcade

---

Question 15.
Sophie often imagined herself with her brother Geoff, riding on a __
(a) motorcycle
(b) a bicycle
(c) cart
(d) a roller coaster

Answer

Answer: (a) motorcycle

---

Question 16.
Sophie sometimes felt that her brother was in some __
(a) daydreams
(b) depression
(c) trouble
(d) gay mood

Answer

Answer: (a) daydreams

---

Question 17.
Geoff worked as a __
(a) director in films
(b) musician
(c) apprentice mechanic
(d) a gardener

Answer

Answer: (c) apprentice mechanic

---

Question 18.
Sophie was closest to
(a) her father
(b) Derek
(c) Jansie
(d) Geoff

Answer

Answer: (d) Geoff

---

Question 19.
Jansie and Sophie were both earmarked for
(a) a doughnut factory
(b) a jewellery store
(c) a biscuit factory
(d) a food outlet

Answer

Answer: (c) a biscuit factory

---

Question 20.
Sophie, after leaving school was keen to open an
(a) salon
(b) boutique
(c) showroom
(d) studio

Answer

Answer: (b) boutique

---

Question 21.
Why is Sophie attracted to Danny and does she meet him in reality?
(a) Because he is a heroic footballer and she meets him in imagination only
(b) because he earns well
(c) because he plays football
(d) because he is smart

Answer

Answer: (a) Because he is a heroic footballer and she meets him in imagination only

---

Question 22.
Which country did Danny play for?
(a) Netherland
(b) Newzealand
(c) Switzerland
(d) Ireland

Answer

Answer: (d) Ireland

---

Question 23.
Why did Sophie like her brother Geoff more than anyone else?
(a) he keeps silent
(b) because he keeps her secret
(c) because she can confide in him
(d) all these

Answer

Answer: (d) all these

---

Question 24.
What are the advantages and disadvantages of fantasizing?
(a) helps in dreaming big
(b) helps in achieving big
(c) develops creative imagination and disadvantage is that it makes people self obsessed.
(d) none of these

Answer

Answer: (c) develops creative imagination and disadvantage is that it makes people self obsessed.

---

Question 25.
Where does Sophie visit to meet Casey in her imagination?
(a) a football ground
(b) in the match
(c) in a hotel
(d) a secret place near canal

Answer

Answer: (d) a secret place near canal

---

Question 26.
What does Jansie ask Sophie?
(a) about Danny Casey
(b) about Mary Quaint
(c) about her dream
(d) the reality behind her meeting with Danny Casey

Answer

Answer: (d) the reality behind her meeting with Danny Casey

---

Question 27.
Why did their favourite team win the match?
(a) Because they played well
(b) they were united
(c) they planned well
(d) because of the goal made by Casey

Answer

Answer: (d) because of the goal made by Casey

---

Question 28.
When does Sophie and her family go to watch the football match?
(a) Sunday morning
(b) Sunday evening
(c) Sunday afternoon
(d) Saturday

Answer

Answer: (d) Saturday

---

Question 29.
Explain- On Saturday they made their weekly pilgrimage to the United
(a) repairing stove
(b) repairing a car
(c) repairing a cooler
(d) went to the United dutifully with a lot of devotion

Answer

Answer: (d) went to the United dutifully with a lot of devotion

---

Question 30.
Why does Sophie feel choked in the house?
(a) because of stove’s steam and dirty dishes
(b) because of foul smell
(c) because of smoke
(d) because of no air

Answer

Answer: (a) because of stove’s steam and dirty dishes

---

Question 31.
Why does she want to be an actress?
(a) to earn money
(b) to be famous
(c) to be a fashion designer
(d) to earn a lot of money and open a boutique to be famous fashion designer.

Answer

Answer: (d) to earn a lot of money and open a boutique to be famous fashion designer.

---

Question 32.
Why does Jansie discourage Sophie to dream big?
(a) because it requires a lot of money
(b) because it is not practical
(c) because it is unrealistic
(d) all these

Answer

Answer: (d) all these

---

Question 33.
Where is Sophie lost?
(a) in her imagination
(b) in her dreams
(c) in her words
(d) in her imagination and dream of owning a boutique shop to become a famous fashion designer

Answer

Answer: (d) in her imagination and dream of owning a boutique shop to become a famous fashion designer

---

Question 34.
Who are Sophie and Jansie?
(a) teenagers who are friends and classmates
(b) neighbourers
(c) colleagues
(d) actors

Answer

Answer: (a) teenagers who are friends and classmates

---

Question 35.
What is the turning point in the story?
(a) when she fights with her brother.
(b) when her father gets angry.
(c) when her brother reveals her story.
(d) when she thinks of meeting Danny Casey- a famous football player

Answer

Answer: (d) when she thinks of meeting Danny Casey- a famous football player

---

Question 36.
What is Sophie in reality?
(a) a dreamer
(b) a fighter
(c) a worker at Biscuit factory
(d) none

Answer

Answer: (c) a worker at Biscuit factory

---

Question 37.
The story Going Places revolve around whom?
(a) a fat boy
(b) an old couple
(c) a teenage girl Sophie, her family and friends
(d) none

Answer

Answer: (c) a teenage girl Sophie, her family and friends

---

Question 38.
what is the meaning of the word “chuffed”?
(a) meaning delighted or very pleased
(b) meaning not happy
(c) meaning frustrated
(d) none

Answer

Answer: (a) meaning delighted or very pleased

Question 39.
What is the significance of the subject discussed in the lesson?
(a) it tells how to deal with friends
(b) it tells how to behave smartly
(c) immediate relevance to the life of school leavers
(d) it tells how to behave with elderly

Answer

Answer: (c) immediate relevance to the life of school leavers

---

Question 40.
What theme does Barton explore in this story?
(a) theme of children’s happiness
(b) theme of adolescent fantasizing and hero worship
(c) theme of elderly people’s happiness
(d) theme of individual happiness

Answer

Answer: (b) theme of adolescent fantasizing and hero worship

---

We hope the given NCERT MCQ Questions for Class 12 English Flamingo Chapter 8 Going Places with Answers Pdf free download will definitely yield fruitful results. If you have any queries related to CBSE Class 12 English Going Places MCQs Multiple Choice Questions with Answers, drop your questions below and will get back to you in no time.