GSEB Class 7 Science Solutions Chapter 17 Forests Our Lifeline

Question 1. Explain how animals dwelling in the forest help it grow and regenerate.
Answer: Creatures assist in the growth and renewal of forests in many methods. They act as nature's cleaners within the forest. Tiny organisms break down dead plant and animal remains, making them decay. Creatures also assist in transferring pollen, which helps many plants to grow. Plant-eating animals support meat-eating animals to thrive by being their sustenance. Therefore, all the plants and animals support each other to flourish in the woodland.
In simple words: Animals help forests grow by cleaning them, pollinating plants, and supporting the food chain. Decomposers break down dead things, returning nutrients to the soil.

Exam Tip: When explaining ecological roles, remember to cover multiple aspects like cleaning, nutrient cycling, pollination, and food web support to score full marks.

Question 2. Explain how forests prevent floods.
Answer: Woodlands are able to soak up a great deal of water. Tree roots take in the water and stop it from running off. Tree roots also allow water to slowly seep deeper into the ground. This action assists in stopping floods.
In simple words: Forests stop floods because trees and their roots absorb a lot of rainwater. This keeps the water from flowing away and helps it soak into the soil.

Exam Tip: Focus on the dual action of tree roots: water absorption and facilitating percolation into the soil, both crucial for flood prevention.

Question 3. What are decomposers? Name any two of them. What do they do in the forest?
Answer: Decomposers are tiny living things that consume dead plants and animal remains. They keep forests tidy, breaking down dead bodies, and putting essential nutrients back into the woodland earth; for example, beetles and grubs.
In simple words: Decomposers are organisms like beetles and grubs that eat dead plants and animals. They clean the forest and put nutrients back into the soil.

Exam Tip: Clearly define decomposers, provide specific examples, and explain their vital role in nutrient recycling and maintaining forest health.

Question 4. Explain the role of forest in maintaining the balance between oxygen and carbon dioxide in the atmosphere.
Answer: Green plants let out oxygen into the air while making their food. Creatures breathe in this oxygen for their breathing process. When animals breathe out, they give off carbon dioxide, which plants then take in. Thus, the oxygen and carbon dioxide movement keeps happening. As woodlands have many plants, they greatly aid this cycle and keep nature in harmony.
In simple words: Forests help balance oxygen and carbon dioxide. Plants release oxygen and absorb carbon dioxide, while animals breathe in oxygen and release carbon dioxide. This continuous cycle keeps the air balanced.

Exam Tip: Describe the process of photosynthesis (plants releasing oxygen, absorbing carbon dioxide) and respiration (animals doing the opposite) to explain the forest's role in gas balance.

Question 5. Explain why there is no waste in the forest.
Answer: No waste exists in the forest as decomposers change all dead plant and animal remains into humus, which mixes with the earth. Therefore, nothing is left unused.
In simple words: There is no waste in a forest because decomposers turn all dead plants and animals into humus, which enriches the soil. Everything is recycled.

Exam Tip: Connect the absence of waste directly to the action of decomposers and the formation of humus, highlighting the natural recycling process.

Question 6. List five products we get from forests.
Answer:
• Forests provide us with various remedies.
• We obtain sap from these woodlands.
• We acquire timber that serves various uses, such as for crafting furniture, making paper, and more.
• Creatures find their meals within the forests.
• We get sealing wax from forests.
In simple words: Forests give us useful things like medicines, gum, wood for furniture and paper, food for animals, and sealing wax.

Exam Tip: When listing products, think broadly about natural resources, food, building materials, and other valuable items derived from forests.

Question 7. Fill in the blank:
(a) The insects, butterflies, honeybees, and birds help flowering plants in ..........
(b) A forest is a purifier of .......... and ..........
(c) Herbs form, the .......... layer in the forest.
(d) The decaying leaves and animal droppings in a forest enrich the ..........
Answer:
(a) pollination
(b) water, air
(c) lowest
(d) soil as humus.
In simple words: (a) Insects help plants with pollination. (b) Forests clean water and air. (c) Herbs make up the lowest layer. (d) Dead leaves and animal waste make the soil rich with humus.

Exam Tip: For fill-in-the-blank questions, read the sentence carefully to understand the context and recall the exact term or concept that completes it accurately.

Question 8. Why should we worry about the conditions and issues related to forests far from us?
Answer: We must be concerned about tree cutting because it causes floods, raises global temperature, reduces animal numbers, destroys homes, and leads to dirt wearing away. Harm to forests directly or indirectly impacts human living spaces and our natural surroundings, so it should be a worry for everyone.
In simple words: We should care about forests everywhere because harming them causes problems like floods, higher temperatures, fewer animals, and soil erosion. These problems affect everyone's environment and lives.

Exam Tip: Emphasize the interconnectedness of ecosystems; problems in distant forests can have global impacts on climate, biodiversity, and human well-being.

Question 9. Explain why there is a need of a variety of animals and plants in a forest.
Answer: Every plant and animal supports woodland existence, and the carbon dioxide-oxygen cycle continues because of these creatures and greenery. Creatures change dead and rotting material into rich humus, making the soil more fertile, which helps plants grow better. All feeding relationships and complex food networks require diverse types of plants and animals.
In simple words: Many different types of plants and animals are needed in a forest to keep the ecosystem healthy. They help with the oxygen-carbon dioxide cycle, enrich the soil, and form strong food chains and webs.

Exam Tip: Highlight biodiversity's importance for ecological balance, nutrient cycling (humus formation), and the stability of food chains and webs.

Question 10. In given fig. the artist has forgotten to put the labels and directions on the arrows. Mark the directions on the arrows and label the diagram using the following labels: clouds, rain, atmosphere, carbon dioxide, oxygen, plants, animals, soil, roots, water table.
Answer: The diagram depicts the interaction between forest elements and the atmosphere. Here's a description of how to label the key components and show their relationships:
• **Atmosphere:** The large area surrounding the forest.
• **Clouds:** Found high in the atmosphere, leading to **Rain**.
• **Rain:** Falls from clouds towards the Earth.
• **Carbon dioxide:** Present in the atmosphere, absorbed by **Plants**.
• **Oxygen:** Released by **Plants** into the atmosphere and absorbed by **Animals**.
• **Plants:** Interact with the atmosphere (gas exchange) and the **Soil** via their **Roots**.
• **Animals:** Live in the forest, exchange gases with the atmosphere, and consume plants.
• **Soil:** The ground layer, where **Roots** are embedded.
• **Roots:** Part of plants, extending into the soil.
• **Water Table:** The level of underground water in the soil.
• **Arrows show flow:** For example, rain falling, gases moving between atmosphere, plants, and animals, and water moving from soil to roots and the water table.
In simple words: The diagram shows how different parts of a forest work together. Clouds bring rain, which goes into the soil. Plants absorb carbon dioxide and release oxygen. Animals breathe oxygen and release carbon dioxide. Everything is connected in a cycle.

Exam Tip: When asked to label a diagram, carefully identify each component and its function in the system to place labels and arrows accurately, showing the correct flow or relationship.

Question 11. Which of the following is not a forest product?
(i) Gum
(ii) Plywood
(iii) Sealing wax
(iv) Kerosene
Answer: (iv) Kerosene
In simple words: Think about things that come directly from trees or plants in a forest. Kerosene is a fuel made from crude oil, which is found underground, not from trees.

Exam Tip: For 'not a product' questions, mentally list common products from the source (e.g., forest) and then identify the option that clearly doesn't fit that category.

Question 12. Which of the following statements is not correct?
(i) Forests protect the soil from erosion.
(ii) Plants and animals in a forest are not dependent on one another.
Answer: (ii) Plants and animals in a forest are not dependent on one another.
In simple words: In a forest, everything is connected. Plants provide food and shelter for animals, and animals help with pollination and seed spread for plants. They absolutely rely on each other.

Exam Tip: When identifying an incorrect statement, look for claims that contradict basic ecological principles or established facts about the given subject.

Question 13. Micro-organisms act upon the dead plants to produce
(i) sand
(ii) mushrooms
(iii) humus
(iv) wood
Answer: (iii) Humus
In simple words: Tiny living things break down dead plants and animals. This process creates a dark, rich material called humus, which helps soil become healthy and fertile.

Exam Tip: Remember the role of decomposers in nutrient cycling; their primary output from dead organic matter is typically humus.

Extended Learning Activities And Projects

Question 1. The Department of Environment is to decide whether some portion of a forest in your area could be cleared for a housing complex. Write a letter to the department explaining your point of view as a concerned citizen.
Answer:
The Director
Department of Environment
New Delhi
Subject – Deforestation in area.
Sir,
I have learned that your department has given approval to remove part of the forest next to my home. About this, I wish to bring your good attention to these points, which are the results of your choice:
(i) Because forests are being destroyed, wild animals will start moving into places where people live, looking for food and homes.
(ii) The weather will alter because of uneven oxygen and carbon dioxide levels. Cutting down trees will make carbon dioxide in the air go up, leading to the greenhouse effect and hotter weather.
(iii) Residents nearby who rely on forest goods will face hardship.
(iv) Removing trees and other plants can lead to the ground wearing away.
(v) Without trees, the earth won't keep water, which will then cause flooding. The points mentioned above are some dangers deforestation could bring to our lives and surroundings. As a worried resident, I ask you to rethink your choice for the benefit of everyone.
Thanking You
Yours faithfully
A concerned citizen
In simple words: This letter expresses concern about cutting down a forest for housing. It explains that this decision will make wild animals move into neighborhoods, change the climate, cause problems for people who depend on forest products, lead to soil erosion, and increase flood risks. The letter asks the department to reconsider for the public's benefit.

Exam Tip: For letter-writing questions, include a clear subject, address the recipient formally, present arguments logically with supporting points, and maintain a respectful tone while conveying your concerns.

Question 2. Visit a forest. Here is a list of points that would make your visit more fruitful.
(a) Make sure that you have permission to go into the forest.
(b) Make sure that you can find your way around. Get a map and go along with someone who is familiar with the area.
(c) Keep a record of the things you see and do. Observations make the visit interesting. Sketches and photographs are useful
(d) You may record bird calls.
(e) Collect different kinds of seeds or hard fruits like nuts.
(f) Try to recognize various types of trees, shrubs, herbs, etc. Make lists of plants from different places in the forest and of different layers. You may not be able to name all the plants, but it is worth recording and seeing where they grow. Make a record of approximate heights of plants, crown shape, bark texture, leaf size, and flower color.
(g) Learn to recognize the animal's droppings.
(h) Interview the forest officials and the people of surrounding villages and other visitors.
Answer: This activity promotes direct viewing and active learning about forest environments. Following the suggested points will help you explore the forest thoughtfully, record your discoveries, and grasp its varied life forms and how they connect. These trips improve real-world knowledge and admiration for nature.
In simple words: This activity lets you learn firsthand about forests. By following the tips, you can explore, observe, and document different plants and animals, improving your understanding and appreciation for nature.

Exam Tip: For experiential questions, understand the objective of the activity and how each suggested step contributes to a comprehensive learning experience.