Life Processes Class 10 Important Questions Science Chapter 6

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Life Processes Class 10 Important Questions with Answers Science Chapter 6

Life Processes Class 10 Important Questions Very Short Answer Type

Question 1.
Name the tissue which transports soluble products of photosynthesis in a plant.   [AI 2008]
Answer:
Phloem tissues

Question 2.
Name the tissue which transports water and mineral in a plant.   [AI 2008]
Answer:
Xylem.

Question 3.
Which pancreatic enzyme is effective in digesting proteins?   [Foreign 2008]
Answer:
Pancreatic trypsin.

Question 4.
Which enzyme, present in saliva breaks down starch?   [Foreign 2008]
Answer:
Salivary amylase.

Question 5.
Name the process by which autotrophs prepare their own food.
Answer:
Photosynthesis.

Question 6.
What would be the consequence of deficiency of haemoglobin in your body?   [CBSE 2013]
Answer:
Hemoglobin is a red pigment which carries oxygen in blood to supply to all the parts of the body. Due to its deficiency the supply of oxygen would be low and the energy released in the body would be also low which may lead to a disease called anemia.

Question 7.
List three characteristics of lungs which make it an efficient respiratory surface.   [CBSE 2013]
Answer:
The three characteristics of the lungs are:

1. Large surface area: Lungs provide a large surface area in the form of alveoli inside for the exchange of gases by diffusion. This helps in the absorption of oxygen.
2. Thin walls: The air sacs/alveoli are thin which allows the quick diffusion of the gases through it.
3. Rich in capillary supply: The alveoli are richly supplied with the capillaries that bring blood with the carbon dioxide and absorbs oxygen.

Question 8.
(a) What is the role of HCl in our stomach?
(b) What is emulsification of fats?
(c) Which protein digesting enzyme is present in pancreactic juice?   [CBSE 2013]
Answer:
(a) The HCl provides acidic medium for the action of enzyme pepsin to act and break down the proteins. It kills the germs, microbes and pathogens that enter the stomach.
(ii) The breaking down of big fat globules into the smaller ones is called emulsification of fats.
(c) Trypsin

Question 9.
List in tabular form three differences between arteries and veins.   [CBSE 2013]
Answer:
Arteries:

• They are deep seated
• They carry oxygenated blood
• They are thick walled so carry blood with lots of pressure

Veins:

• They are superficial
• They carry deoxygenated blood
• They are thin walled and hence carry blood with less pressure.

Question 10.
Which enzyme, present in saliva breaks down starch?   [CBSE 2014]
Answer:
Mention the raw materials required for photosynthesis
Salivary amylase present in saliva breaks down starch.
Raw material required for photosynthesis are:

1. Carbon Dioxide: Plants get CO₂ from atmosphere through stomata.
2. Water: Plants absorb water from soil through roots
3. Sunlight: It is absorbed by the chlorophyll present in the leaves.

Life Processes Class 10 Important Questions Short Answer Type

Question 1.
What process in plants is known as transpiration?   [AI 2008]
Answer:
The loss of water by leaves through small pores called stomata is known as transpiration.

Question 2.
How do autotrophs obtain CO₂ and N₂ to make their food?   [AI 2008]
Answer:
CO₂ is obtained from leaves through stomata pores and N₂ is obtained in combined form, e.g. nitrates, through roots in dissolved form.

Question 3.
Write one function each of the following components of the transport system in human beings.
(a) Blood vessels
(b) Blood platelets
(c) Lymph
(d) Heart   [AI 2008]
Answer:
(a) Blood vessels – Carry blood for transportation from part of the body to other.
(b) Blood platelets – Helps in blood clotting during injury.
(c) Lymph – Carries digested and absorbed fat for transportation.
(d) Heart – It is a pumping machine which pumps blood to reach all the parts of the body.

Question 4.
Write any 3 differences between aerobic and anaerobic respiration.   [AI 2008]
Answer:
Aerobic

1. Takes place in presence of O₂.
2. End products are CO₂ + H₂O + energy.
3. Large amount of energy is released.

Anaerobic:

1. Takes place in absence of oxygen.
2. End products are ethanol + CO₂ + energy.
3. Less amount of energy is released.

Question 5.
What is the role of saliva in the digestion of food?   [AI 2008]
Answer:
It converts insoluble starch into soluble sugar and makes the dry food wet.

Question 6.
How are fats digested in our body? Where does this process take place?    [Foreign 2008]
Answer:
Fats when enter our alimentary canal bile juice emulsifies the fat in small intestine the lipase enzyme produced by pancreas digest it to form fatty acids.

Question 7.
What is the role of acid in our stomach?
Answer:
Acid makes the medium in stomach acidic so as to facilitate the action of pepsin. It also kills germs that enter our stomach with food.

Question 8.
What is the mode of nutrition in human beings?
Answer:
Holozoic mode of nutrition i.e., heterotrophic in nature.

Question 9.
Why do the walls of the trachea not collapse when there is less air in it?   [CBSE 2012]
Answer:
Rings of cartilages are present in trachea. These rings support the trachea and do not allow the trachea to collapse when there is less air in it.

Question 10.
In human alimentary canal, name the site of complete digestion of various components of food. Explain the process of digestion.   [CBSE 2012]
Answer:
The site of complete digestion of carbohydrates, fats, proteins is small intestine.

Process of digestion:
Food is chewed with digestion of starch by the action of salivary amylase present in mouth. The formed bolus passes down the esophagus into the stomach by the action of peristalsis. Gastric juices further acts on food for the digestion of proteins and forms chyme.

Chyme enters the duodenum where digestive enzymes from pancreas and bile juice from liver mixes with it and then passes through small intestine. Absorbtion of nutrients occur in small intestine and reabsorption of water and minerals too.

Question 11.
List the three kinds of blood vessels of human circulatory system and write their functions in tabular form.
Answer:
Arteries:
It carries oxygenated blood away from the heart to all the parts of the body

Veins:
It carries de-oxygenated blood from the different parts of the body to the heart

Capillaries:
The single walled tubes helps in the exchange of materials within the cell and the blood
by diffusion.

Question 12.
Why do herbivores have longer, small intestine than carnivores?   [CBSE 2014]
Answer:
Herbivores feed on the plants and its parts which contain cellulose. Digestion of cellulose takes longer time and hence to allow the complete digestion the small intestine is longer whereas the carnivores eat flesh and meat which does not need cellulose enzyme and long time for digestion.

Question 13.
Write correct sequence in four steps about the method for the preparation of temporary mount of a stained leaf peel.   [CBSE 2014]
Answer:

1. Take a leaf and fold it to remove the lower surface peel with the forceps.
2. Keep the peel in a watch glass containing dilute safranin for staining.
3. Place the leaf on clean glass slide, add a drop of glycerin and gently place a cover slip over it.
4. Remove the extra stain with the blotting paper and observe it under a microscope.

Question 14.
In mammals and birds why is it necessary to separate oxygenated and de-oxygenated blood? [CBSE 2014]
Answer:
In mammals and birds the energy requirement for their life processes is high and hence large amount of oxygen is required to break down the glucose which would supply the energy during cellular respiration. Hence the oxygenated blood is required to supply oxygen to each and every cell and this works efficiently only if the deoxygenated blood is seperated from the oxygenated one.

Question 15.
Draw a neat diagram of excretory system of human beings and label on it:
(i) Left kidney
(ii) Urinary bladder [CBSE 2014]
Answer:

Question 16.
Draw a diagram of human respiratory system and label on it:
(i) Diaphragm
(ii) Larynx
(iii) Trachea   [CBSE 2014]
Answer:

Question 17.
(a) Name the site of exchange of material between the blood and surrounding cells
(b) Draw a schematic representation of transport and exchange of oxygen and carbon dioxide in human body.   [CBSE 2014]
Answer:
(a) Capillaries
(b)

Question 18.
What are enzymes? Name any one enzyme of our digestive system and write its function.   [CBSE 2015]
Answer:
Enzymes are biological catalysts that increase the rate of chemical reactions without being used up. For example: Amylase catalyses helps in the breakdown of starch into sugars in the mouth and small intestine.

Question 19.
(i) Write the balanced chemical equation for the process of photosynthesis.
(ii) When do the desert plants take up carbon dioxide and perform photosynthesis?
Answer:
(i) Photosynthesis can be represented using a chemical equation. The overall balanced equation is

(ii) Desert plants open up their stomata during night and take in CO₂. Stomata remains closed during the day time to prevent the loss of water by transpiration. They store CO₂ in their cells until the sun comes out and they can carry on with photosynthesis during the day time.

Question 20.
In single-celled organisms diffusion is sufficient to meet all their requirements of food, exchange of gases or removal of wastes but it is not in case of multicellular organisms. Explain the reason for this difference.    [CBSE 2015]
Answer:
Unicellular organisms can absorb sufficient oxygen because of its complete contact with the atmosphere, but in multicellular organisms the rate of absorption and diffusion becomes very less because all cells are not in direct contact with the atmosphere. Multicellular organisms require greate amount of oxygen to sustain life processes which cannot be fulfilled by the process of diffusion.

Question 21.
Draw a diagram of human excretory system and label kidneys, ureters on it.    [CBSE 2015]
Answer:

Question 22.
Name the acid present in the following:
(i) Tomato
(ii) Vinegar
(iii) Tamarind   [CBSE 2015]
Answer:
(i) Oxalic acid
(ii) citric acid
(iii) Tartaric acid.

Question 23.
State the role of the following in human digestive system:
(i) Digestive enzymes
(ii) Hydrochloric acid
(iii) Villi    [CBSE 2015]
Answer:
(i) Digestive enzymes – Foods need to be broken into their small or simpler molecules so that they can be absorbed into the bloodstream. However, the physical breakdown of food is not enough. Enzymes are hence needed for the chemical breakdown of food and speeding up the digestive process. The products of digestion should be smaller enough to be absorbed.

(ii) Hydrochloric acid helps to kill the germs which might have entered into the system through food. It creates acidic medium for the pepsin to act on food to break down proteins.

(iii) Villi are finger like projections in the small intestine. They help to increase the surface area for absorption of the digested food. Villi are richly supplied with blood vessel which help to absorb digested food from the blood stream.

Life Processes Class 10 Important Questions Long Answer Type

Question 1.
(a) Draw a diagram depicting human alimentary canal and label on it gall bladder, liver and pancreas.
(b) State the roles of liver and pancreas.
(c) Name the organ which performs the following functions in human:
(i) Absorption of digested food.
(ii) Absorption of water.    [AI 2008]
Answer:
(a)

(b) Liver – It secretes bile juice which makes medium alkaline and emulsifies the fat.
Pancreas – It secretes pancreatic juice which contains amylase, lipase and trypsin.
Amylase digest carbohydrates
Lipase digest fats
Trypsin digest proteins

(c) (i) Villi in small intestine absorbs digested food.
(ii) Large intestine absorbs water.

Question 2.
(a) Name two different ways in which glucose is oxidised to provide energy in various organisms.
(b) Write any two differences between the two ways of oxidation of glucose in organisms.   [AI 2008]
Answer:
(a) Breakdown of glucose by various pathways for different organisms are:

(b) Difference in oxidation of glucose
Aerobic:

1. Glucose is oxidised in presence of O₂.
2. End products are CO₂ + H₂O + Energy.
3. Large amount of energy is released.

Anaerobic:

1. Oxidised in absence of O₂.
2. End products are Ethanol + CO₂ + Energy.
3. Less amount of energy is released.

Question 3.
(a) How do autotrophs prepare food?
(b) List three events which occur during this process.
(c) State two sources from which plants obtain nitrogen for the synthesis of proteins and other compounds.   [Foreign 2008]
Answer:
(a) Autotrophs prepare their own food by photosynthesis and few by chemotropism.

(b) Events occurring during Photosynthesis:

• Absorption of light energy by chlorophyll.
• Conversion of light energy to chemical energy and splitting of water molecules into hydrogen and oxygen.
• Reduction of carbon dioxide into carbohydrates.

(c) Plants obtain nitrogen from the soil in dissolved form of nitrates or nitrites. Rhizobium bacteria converts atmospheric nitrogen into organic compounds.

Question 4.
What are stomata? Draw a labelled diagram of stomata. Write two functions of stomata.   [Foreign 2008]
Answer:
Stomata are small pores present on the leaves underside.

Two functions of stomata:

1. Allows the exchange of gases, O₂ and CO₂.
2. It helps in losing extra water by transpiration and creates suction pull which helps the water to rise in xylem.

Question 5.
(a) Draw a diagram of human alimentary canal and label on it.
Oesophagus, gall bladder, liver and pancreas.
(b) Explain the statement, “Bile does not contain any enzyme but it is essential for digestion.”    [AI 2009]
Answer:
(a)

(b) Bile does not contain any enzyme, but it makes the medium in small intestine basic so that trypsin acts on proteins in this medium.
It emulsifies fat i.e., breaks large globules of fat into smaller ones.

Question 6.
(a) Draw a diagram of excretory system in human being and label on it.
Aorta, Vena cava, Urinary bladder, Urethra.
(b) List two vital functions of the kidney.
Answer:
(a)

(b) Kidney helps in
(i) Excretion of waste from the body and
(ii) Osmoregulation, maintain the level of water in the body.

Question 7.
(a) Draw a sectional view of human heart and label on it aorta, pulmonary vein, vena cava, left ventricle.
(b) Why is double circulation of blood necessary in human being?    [AI 2009]
Answer:
(a)

(b) The blood passes through the heart twice. Right side of the heart receives deoxygenated blood which is circulated to lungs for purification. At the same time the left side of the heart receives oxygenated blood which is circulated to the body. This is called double circulation.

Question 8.
(a) Draw the structure of a nephron and label the following on it: glomerulus, bowman’s capsule, renal artery, collecting duct.
(b) What happens to glucose that enters the nephron along with filtrate?
Answer:
(a)

(b) The glucose that enters the nephron along with filtrate is reabsorbed by the blood capillaries.

Question 9.
(a) Draw a diagram of the human respiratory system and label on it alveolar sac, bronchioles, larynx and trachea.
(b) How are the lungs designed in human beings to maximise the area of exchange of gases?   [Foreign 2009]
Answer:
(a)

(b) Lungs have bronchioles (small tubes) coming from the bronchi. The bronchioles at the terminals form a balloon like structure called alveoli which increases the surface area for exchange of gases and is richly supplied with blood capillaries.

Question 10.
(a) Draw a diagram to show open stomatal pore and label on it:
(i) guard cells
(ii) chloroplast
(b) State two functions of stomata.
(c) How do guard cells regulate the opening and closing of stomatal pore?   [CBSE 2012]
Answer:
(a) Open stomatal

(b) (i) It helps in the exchange of gases like carbon dioxide and oxygen as per the requirement for the photosynthesis and respiration of the plants.
(ii) It also helps in the loss of water in the form of water vapour called transpiration.

(c) Guard cells swell when water enters into it by the process of osmosis and thereby opens the stomata pore for the loss of the water.
When the water is lost it shrinks and closes the stomata pore.

Question 11.
(a) Draw a diagram of human respiratory system and label the following:
(i) part where air is filtered by fine hair and mucus
(ii) part which terminates in balloon-like structures
(iii) balloon-like structures where exchange of gases takes place.
(iv) part which separates chest cavity from abdominal cavity.
(b) Why is the rate of breathing in aquatic organisms much faster than in terrestrial organisms? [CBSE 2012]
Answer:
(a)

(b) The oxygen dissolved in water is very less and the aquatic animals do not get sufficient oxygen unless they breathe fast to meet their energy needs.

Question 12.
Draw a diagram of human excretory system and label kidney, ureter, renal artery and urethra. State in brief the function of:
1. renal artery
2. kidney
3. ureter
4. urinary bladder   [CBSE 2013]
Answer:
(a)

Functions:

1. Renal artery: It brings the impure blood to the kidneys for the purification.
2. Kidney: The kidneys purify the blood by removing the waste from it and regulates the body’s fluid volume and mineral composition by reabsorbing the water and required electrolytes.
3. Ureter: It is a tube that carries urine from the kidney to the urinary bladder.
4. Urinary bladder: It is a muscular sac that stores urine before it is excreted.

Question 13.
(a) Draw a diagram of excretory system in human beings and label the following parts. Aorta, kidney, urinary bladder and urethra.
(b) How is urine is produced ans eliminated?
Answer:
(a)

(b) Urine is produced by the filtration of blood by the kidneys. It is then passed through the ureters to urinary bladder where it is stored till urination. Once a person feel like urinating it is passed to urethra to get eliminated from the body.

Question 14.
(a) Explain how does the exchange of gases occur in plants across the surface of stems, roots and leaves.
(b) How are water and minerals transported in plants? [CBSE 2015]
Answer:
(a) In plants there are tiny pores called stomata on leaves and lenticels in stem which facilitate the exchange of gases. Carbon dioxide is taken in and oxygen is given out during photosynthesis and vice versa during respiration.

(b) Water and minerals are transported within the plant by the xylem vessels mainly in an upward direction.
Phloem transports the products of photosynthesis within the plant, to all parts like the stem, roots fruits etc. in all directions.