How Nature Works in Harmony Class 8 Question Answer Science Chapter 12

Start by reviewing these Class 8 Science Curiosity Solutions Chapter 12 How Nature Works in Harmony Question Answer to strengthen your knowledge.

Class 8 Science Curiosity Chapter 12 Question Answer

Class 8 Science Ch 12 How Nature Works in Harmony Question Answer

Class 8 Science Chapter 12 How Nature Works in Harmony Question Answer (InText)

Question 1.
How does deforestation and changes in rainfall patterns cause elephants to enter human farms and villages? Probe and ponder. (Page 190)
Answer:
Loss of forest cover reduces the natural habitat and food sources for elephants. Irregular rainfall affects the growth of plants and availability of water in forests. Due to this, elephants move into nearby farms and villages in search of food and water, leading to human-wildlife conflict.

Question 2.
If you were a tree in a dense forest, how would you interact with water, sunlight, animals, and other parts of the forest? Probe and ponder. (Page 190)
Answer:
As a tree, I use sunlight, water, and soil nutrients to grow and make food. I give oxygen, shelter, and fruits to animals. My roots hold soil, and fallen leaves enrich it. I live in balance with all forest life, helping the ecosystem stay healthy.

Question 3.
If two bird species compete for the same fruit, how might their lifestyle or behavior change over time? (Page 190)
Answer:
Over time, one bird may start eating different food or feeding at a different time to avoid competition. This helps both species survive by reducing direct conflict.

Question 4.
What factors determine whether an organism lives in water or on land? (Page 190)
Answer:
The factors that determine whether an organism lives in water or on land include the availability of oxygen, sunlight, temperature, moisture, and type of shelter. Aquatic organisms are adapted to breathe dissolved oxygen and often have fins or gills for movement and respiration, while land organisms breathe air through lungs or other structures and require solid surfaces to move and live.

Question 5.
Do you think Earth can thrive without humans, and can humans survive without the Earth? (Page 190)
Answer:
Yes, Earth can survive without humans. Nature will continue to thrive. But humans cannot survive without Earth, as we depend on it for air, water, food and shelter.

Question 6.
How do fish survive in a pond? (Page 192)
Answer:
A fish survives in a pond by using special body features and adapting to its surroundings. It breathes through gills, which take in oxygen dissolved in the water.

Fish use their fins and tail to swim and move around in search of food like small insects, plants, or other tiny animals. The pond also provides shelter among plants and rocks, keeping them safe from predators.

Question 7.
Can a habitat have only one type of living organism? (Page 194)
Answer:
No, a habitat cannot have only one type of living organism. It usually supports many different kinds of plants and animals that depend on each other for food, shelter, and survival.

Question 8.
How does the population of fish in a pond affect the seed production in nearby plants? (Page 195)
Answer:
Fish in a pond eat dragonfly larvae, reducing the number of dragonflies. Dragonflies usually eat flies bees and butterflies. With fewer dragonflies, more bees, flies, and butterflies survive, these insects help pollinate flowers. As a result, plants near ponds with fish may produce more seeds due to better pollination.

Question 9.
Is it possible for ecosystems to overlap or share common areas? (Page 197)
Answer:
Yes, ecosystems can overlap when two different ecosystems share some of the same space, resources, or organisms. For example, a mangrove forest can be part of both a terrestrial and aquatic ecosystem.

Question 10.
How do plants get their food? (Page 198)
Answer:
Plants make their own food through a process called photosynthesis. In this process, plants use sunlight, carbon dioxide from the air, and water from the soil to produce glucose (a type of sugar) and oxygen.

Question 11.
How can we connect the feeding relationships between organisms within a particular ecosystem?” (Page 198)
Answer:
We can connect feeding relationships in an ecosystem by using food chains and food webs, which show who eats whom and how energy flows between organisms.

Question 12.
How can one organism be linked to many others through feeding relationships in an ecosystem?” (Page 200)
Answer:
One organism can be linked to many others through a food web, as it may serve as food for several predators and may also feed on different prey, forming multiple feeding connections in the ecosystem.

Question 13.
Does nature really waste anything? (Page 201)
Answer:
No, nature doesn’t waste anything. Every dead plant or animal is broken down by decomposers and recycled back into the ecosystem as nutrients for other living things.

Question 14.
What are the effects of human interference in nature? (Page 202)
Answer:
When we interfere with nature, it can disturb the balance of ecosystems, harm wildlife, reduce biodiversity, and lead to problems like pollution and climate change.

Question 15.
How can we protect forests, rivers, and wetlands from damage? (Page 204)
Answer:
We can protect forests, rivers, and wetlands by reducing deforestation, preventing pollution, using resources wisely, planting trees, and supporting conservation efforts that preserve natural habitats.

Question 16.
How do unsustainable farming practices harm both the environment and human health? (Page 205)
Answer:
Unsustainable farming harms the environment by degrading soil, polluting water, and reducing biodiversity. It also affects human health through pesticide exposure and contaminated food and water.

Question 17.
Which practice do you think can help farmers protect the soil, the environment, and our food security in the future? (Page 206)
Answer:
Practices like sustainable farming, crop rotation, organic manure use, and reduced chemical inputs can help protect soil, the environment, and ensure food security for the future.

How Nature Works in Harmony Class 8 Questions and Answers (Exercise)

Question 1.
Refer to the given diagram and select the wrong statement.

(a) A community is larger than a population.
(b) A community is smaller than an ecosystem.
(c) An ecosystem is part of a community.
Answer:
(c) An Ecosystem is part of a community

Question 2.
A population is part of a community. If all decomposers suddenly disappear from a forest ecosystem. What changes do you think would occur? Explain why decomposers are essential.
Answer:
If all decomposers disappeared, dead plants and animals would pile up, and nutrients would not return to the soil. This would harm plant growth and affect the entire food chain.

Decomposers are essential for recycling nutrients and keeping ecosystems healthy.

Question 3.
Selvam from Cuddalore district, Tamil Nadu, shared that his village was less affected by the 2004 Tsunami compared to nearby villages due to the presence of mangrove forests. This surprised Sarita, Shabnam, and Shijo. They wonderd if mangroves were protecting the village. Can you help them understand this?
Answer:
Mangrove forests act as natural barriers. Their dense roots and thick vegetation slow down powerful waves and reduce the impact of natural disasters like tsunamis. In Selvam’s village, the mangroves helped absorb the energy of the waves, protecting the area from major damage. That’s why his village was less affected than others without mangroves.

Question 4.
Look at this food chain

If frogs disappear from this ecosystem, what will happen to the population of grasshoppers and snakes? Why?
Answer:
It frogs disappear, the grasshopper population will increase because there will be no predators to control their numbers. At the same time the snake population will decrease because frogs are their main food source and without then, snakes may struggle to survive.

Question 5.
In a school garden students noticed fewer butterflies the previous season. What could be the possible reasons? What steps can students take to have more butterflies on campus?
Answer:
Fewer butterflies may be due to the lack of flowering plants, use of pesticides, or loss of butterfly-friendly habitat.

Steps students can take
They can plant more nectar-rich flowers. Avoid using chemicals.
Create a butterfly-friendly garden to attract butterflies back to the campus.

Question 6.
Why is it not possible to have an ecosystem with only producers and no consumers or decomposers?
Answer:
An ecosystem with only producers is not possible because consumers are needed to transfer energy by eating producers.

The decomposers are essential to break down dead matter and return nutrients to the soil.

Without consumers and decomposers, the flow of energy and recycling of nutrients would stop, causing the ecosystem to collapse.

Question 7.
Observe two different places near your home or school (e.g., a park and a roadside). List the living and non-living componenets you see. How are the two ecosystems different?
Answer:
Observation from two places i.e. park and roadside are as follows

Component	Park	Roadside
Living (Biotic)	Trees, grass, butterflies, ants, birds, squirrels.	Weeds, crows, small plants
Non-living	Soil, sunlight, water.	Air, Dust, heat from vehicles

The park ecosystem is richer in biodiversity with more plants, insects, and birds due to better care and availability of water.

The roadside ecosystem has fewer living organisms and harsher conditions like pollution and less greenery, making it less supportive for many forms of life.

Question 8.
Human-made ecosystems like agricultural fields are necessary, but they must be made sustainable. Comment on the statement.
Answer:
Human-made ecosystems like agricultural fields are essential for producing food and supporting human needs. However, if not managed properly, they can harm the environment through overuse of fertilisers, pesticides, and water. To protect soil health, biodiversity, and future food security, it is important to make agriculture sustainable, by using eco-friendly methods like crop rotation, organic farmimg, and conserving natural resources.

Question 9.
If the Indian hare population drops because of a disease, how would it affect the number of other organisms?

Answer:
If the Indian hare population drops due to a disease, animals that eat hares like foxes, may have less food and their numbers might decrease.

At the same time, the plants that hares feed on like grasses and small herbs may increase because fewer hares are eating them.

This increases the population of deer also due to more vegetation.This change can disturb the balance of the entire food web.

Class 8 Science Chapter 12 Question Answer (Activities)

Activity 1 (Page 191)

Aim
To identify the living and non – living things in two different habitat

Procedure

1. Identify two habitats in your surroundings.
2. These could be any two of the following: a pond, a forest, an agricultural farm, or even a large tree like banyan, mango, or pilkhan (white fig) tree.
3. List the living beings and non-living things that you observe for each habitat.

Observation
• The list of living beings and non-living things are as follows

Pond	Forest
Living being Fish, frogs turtles dragonflies, snails, water beetles, mosquito larvae, algae, duckweed, lotus, waterlilies	Deer, monkeys, tigers, birds, insects, snakes, Elephants, trees, herbs, climbers fungi
Non-living things Water, sunlight, mud, rocks and pebbles	Soil, sunlight, water, stones

Activity 2 (Page 193)

Aim
To identify the population of a particular type of plant by counting them.

Procedure

1. Divide students into four to five groups.
2. Each group may identify any two organisms, plant(s) or animal(s).
3. Mark an area of 1 m x 1 m in your school garden.
4. Identify your organisms in this area, and count their numbers.

Observation
The observation is as follows

Name of organism	Population (Number of individual organism)
Plant 1 Grasses	20
Plant 2 Marigold plant	5
Animal 1 Lady bug	10
Animal 2 Ant	15

This activity showed that even a small 1 m × 1 m area in the school garden supports a variety of living organisms.

Activity 3 (Page 197)

Aim
To study eating habits of different organisms

Procedure

1. Study a forest ecosystem carefully.
2. List different types of organisms found in forest.
3. Using the internet or school library find out what do these organisms eat.

Observation
Following observations are obtained from the forest ecosystem.

Activity 4 (Page 199)

Aim
To prepare food chain of a grassland ecosystem

Procedure

1. Consider the following organisms that we can spot in a grassland ecosystem-grass, frog, hare, fox, grasshopper, snake and eagle.
2. Draw the feeding relationships for organisms by adding arrows,

Observation
The feeding relationship between these organism is as follows
Grass → Grasshopper → Frog → Snake → Eagle
Grass → Hare → Fox

Activity 5 (Page 199)

Aim
To draw a ecological pyramid

Procedure

1. Consider a crop field with millets, mouse and eagle.
2. Count the number of each type of organism in the field.
3. Make a table and set a number in the table against each of the organisms.
4. Arrange the numbers in the ascending order, consider the highest number at the base and the lowest at the top.

Observation
The total number of each type of organism is as follows:

Millets	Numbers
Mouse	100
Eagle	20
Millets	4

By arranging the numbers in the ascending order, following figure is obtained