Table of Contents
Forests: Our Lifeline – Worksheets
Hello Students,
Welcome to the worksheets based on the chapter “Forests: Our Lifeline.” This chapter is an important part of your science curriculum, as it helps you understand the crucial role forests play in sustaining life on Earth. It sheds light on the interconnectedness of various life forms and their dependence on forests.
In this chapter, you have explored:
- The Role of Forests in Nature: Understanding how forests act as ‘green lungs’ and water-purifying systems in our environment.
- Flora and Fauna in Forests: Learning about the diverse range of plants and animals that inhabit forests and their interdependence.
- Layers of a Forest: Exploring the different layers in a forest, including the canopy, understorey, and forest floor.
- Forests and Biodiversity: Understanding the significance of biodiversity in forests and how it contributes to the stability and health of our planet.
- Forests and Their Products: Learning about various products we obtain from forests and their importance in our daily lives.
- Conservation of Forests: Emphasising the need to preserve and protect forests for the future.
The worksheets include a variety of questions aimed at testing and enhancing your knowledge of these concepts. They range from simple recall of information to more complex questions that require critical thinking and application of what you have learned. These exercises will help you prepare for your exams and deepen your appreciation of the vital role forests play in our world.
Also Check – Class 7 Science -Chapter 17 – Forests: Our Lifeline -Detailed Notes
Worksheet 1 – Chapter 12 – Forests: Our Lifeline – Student Worksheet (Unsolved)
Structure of a Forest:
(a) Explain the role of the canopy in a forest ecosystem.
(b) Describe the various layers of a forest and their significance.
Components of the Forest:
(a) List and explain the roles of different types of organisms found in a forest.
(b) Discuss how decomposers contribute to forest ecology.
True or False – Justify Your Answer:
(a) Forests do not have any role in the water cycle. (T/F)
(b) Scavengers and decomposers perform the same function in the forest. (T/F)
Multiple Choice Questions:
(a) Which of the following is a benefit provided by forests?
(i) Air purification
(ii) Desertification
(iii) Increasing soil erosion
(iv) Reducing rainfall
(b) What is the main role of green plants in a forest?
(i) Providing shelter to animals
(ii) Producing food through photosynthesis
(iii) Acting as decomposers
(iv) Scavenging dead animals
Environmental Impact:
Discuss the role of forests in maintaining the balance of oxygen and carbon dioxide in the atmosphere.
Fill in the Blanks:
(a) The __________ layer of a forest consists of shrubs and bushes.
(b) Forests act as a natural absorber of __________ and help in controlling floods.
Significance of Forests:
Explain the importance of forests in providing habitat for wildlife and maintaining biodiversity.
Scenario-Based Question:
If a large area of a forest is cleared, what are the potential environmental consequences?
Discussion-Based Questions
Discuss the necessity of forest conservation and the actions that can be taken to protect and preserve forests.
Also Check – Rapid Revision – Class 7 Science -Chapter 17- Forest our Lifeline – Complete Notes
Worksheet 1 – Chapter 12 – Forests: Our Lifeline – Solved Worksheet with Answer
Structure of a Forest:
(a) Role of the Canopy in a Forest Ecosystem:
The canopy, formed by the uppermost branches and leaves of tall trees, acts as a roof over the forest ground. It plays a critical role in regulating the amount of sunlight and rain that reaches the forest floor, supports a diverse range of wildlife, and aids in the photosynthesis process vital for the forest’s health.
(b) Layers of a Forest and Their Significance:
The forest is composed of various layers, each with unique ecological importance. The canopy layer provides habitat for birds and arboreal animals. The understorey, consisting of shrubs and smaller trees, offers shelter and food for various species. The forest floor, rich in decomposing matter, supports fungi, bacteria, and insects, contributing to nutrient cycling.
Components of the Forest:
(a) Roles of Different Organisms in a Forest:
Forests host diverse organisms, including plants, animals, decomposers, and scavengers. Plants produce food and oxygen, offer habitat, and form the base of the food chain. Animals, categorised as herbivores, carnivores, and omnivores, play roles in pollination, seed dispersal, and maintaining the food web. Decomposers break down dead matter, recycling nutrients into the soil.
(b) Contribution of Decomposers to Forest Ecology:
Decomposers, such as bacteria and fungi, break down dead organic matter, returning essential nutrients to the soil. This process is vital for nutrient cycling, supporting plant growth and maintaining soil health, which is crucial for the sustainability of the forest ecosystem.
True or False – Justify Your Answer:
(a) Forests do not have any role in the water cycle. (F) – Forests play a significant role in the water cycle through transpiration and interception, contributing to cloud formation and rainfall.
(b) Scavengers and decomposers perform the same function in the forest. (F) – Scavengers consume dead animals but do not break them down into simpler substances, while decomposers break down both dead plants and animals into simple, usable forms.
Multiple Choice Questions:
(a) Benefit Provided by Forests:
Answer: (i) Air purification – Forests purify air by absorbing pollutants and producing oxygen through photosynthesis.
(b) Main Role of Green Plants in a Forest:
Answer: (ii) Producing food through photosynthesis – Green plants synthesise their food using sunlight, water, and carbon dioxide, forming the base of the forest food web.
Environmental Impact:
Role of Forests in Maintaining Oxygen and Carbon Dioxide Balance:
Forests are critical in maintaining the balance between oxygen and carbon dioxide. Through photosynthesis, plants absorb carbon dioxide and release oxygen, supporting life on Earth. Forests also act as carbon sinks, storing significant amounts of carbon, which helps mitigate climate change.
Fill in the Blanks:
(a) The understorey layer of a forest consists of shrubs and bushes.
(b) Forests act as a natural absorber of rainwater and help in controlling floods.
Significance of Forests:
Importance in Providing Habitat and Maintaining Biodiversity:
Forests provide diverse habitats for a wide range of wildlife, supporting biodiversity. They offer food, shelter, and breeding grounds for numerous species, playing a crucial role in preserving ecological balance and biodiversity.
Scenario-Based Question:
Environmental Consequences of Forest Clearing:
Clearing a large area of a forest can lead to habitat loss, decreased biodiversity, disrupted ecosystems, increased soil erosion, altered water cycles, and exacerbated climate change due to the release of stored carbon.
Discussion-Based Questions
Necessity of Forest Conservation:
Forest conservation is crucial for maintaining ecological balance, preserving biodiversity, and ensuring environmental sustainability. Actions like reforestation, sustainable forestry practices, protecting existing forests from deforestation, and raising awareness about the importance of forests are essential steps in conservation efforts.
Also Check – Chapter 17- Forest our Lifeline – Class 7 Extra questions with Answers
Worksheet 2 – Chapter 12 – Forests: Our Lifeline – Student Worksheet (Unsolved)
Understanding Forest Structure:
(a) Describe the role and importance of the canopy layer in a forest ecosystem.
(b) What functions do the understorey layers (top layer, shrub layer, herb layer) and forest floor serve in a forest?
Forest Ecosystem Dynamics:
(a) Explain how plants, as primary producers, support the forest ecosystem.
(b) Discuss the roles of different types of animals (herbivores, carnivores, omnivores) in a forest ecosystem.
True or False – Provide Justifications:
(a) Decomposers in a forest are less important than producers and consumers. (T/F)
(b) Forests have no significant role in influencing climate and weather patterns. (T/F)
Multiple Choice Questions:
(a) What is the primary function of humus in forest soil?
(i) Providing shelter for animals
(ii) Enhancing soil fertility
(iii) Decreasing soil water retention
(iv) Reflecting sunlight to lower layers
(b) Which component of the forest ecosystem is crucial for nutrient cycling?
(i) Carnivores
(ii) Scavengers
(iii) Decomposers
(iv) Herbivores
Environmental Impact:
Elaborate on the role of forests in balancing oxygen and carbon dioxide in the atmosphere.
Fill in the Blanks:
(a) The roots of trees in a forest help prevent __________ and __________.
(b) __________ and __________ are two key processes involved in the water cycle facilitated by forests.
Conservation Strategies:
What are some effective methods for conserving forests, and why is forest conservation crucial for environmental health?
Scenario-Based Question:
If a particular forest area experiences significant deforestation, what immediate and long-term ecological impacts might this have?
Discussion-Based Questions
Discuss how the biodiversity in forests contributes to the ecological balance and why it is vital to protect it.
Also Check – NCERT Solutions for Class 7 Science Chapter 17 Forests Our Lifeline
Worksheet 2 – Chapter 12 – Forests: Our Lifeline – Solved Worksheet with Answer
Understanding Forest Structure:
(a) Role and Importance of the Canopy Layer:
The canopy layer, formed by the uppermost branches of trees, plays a crucial role in a forest ecosystem. It acts as a shield, regulating the amount of sunlight and moisture that reaches the lower layers. The canopy supports a diverse range of life, including birds, insects, and epiphytic plants, and is crucial for processes like photosynthesis and habitat provision.
(b) Functions of Understorey Layers and Forest Floor:
The understorey layers, including the top layer, shrub layer, and herb layer, provide habitat for various animals and plants that thrive in shaded environments with limited sunlight. The forest floor, rich in organic matter from decaying leaves and dead organisms, is essential for decomposers like fungi and bacteria, which break down this material, enriching the soil and facilitating nutrient cycling.
Forest Ecosystem Dynamics:
(a) Roles of Plants as Primary Producers:
Plants are the primary producers in a forest ecosystem. Through photosynthesis, they convert sunlight into energy, forming the base of the food chain. They provide oxygen, food, and shelter for other forest inhabitants and play a significant role in environmental processes like carbon sequestration and water regulation.
(b) Roles of Different Types of Animals:
Herbivores, such as deer and rabbits, feed on plants and help in seed dispersal. Carnivores, like tigers and owls, maintain the balance in animal populations. Omnivores, including bears and raccoons, consume a varied diet and contribute to the diversity of the ecosystem.
True or False – Justifications:
(a) Decomposers in a forest are less important than producers and consumers. (F) – Decomposers are crucial for recycling nutrients back into the soil, supporting plant growth and maintaining ecological balance.
(b) Forests have no significant role in influencing climate and weather patterns. (F) – Forests play a significant role in climate regulation by influencing temperature and rainfall patterns and contributing to the water cycle.
Multiple Choice Questions:
(a) Primary Function of Humus in Forest Soil:
Answer: (ii) Enhancing soil fertility – Humus enriches the soil by providing essential nutrients and improving soil structure.
(b) Component Crucial for Nutrient Cycling:
Answer: (iii) Decomposers – They break down dead organic matter, releasing nutrients into the soil.
Environmental Impact:
Role of Forests in Balancing Oxygen and Carbon Dioxide:
Forests absorb carbon dioxide and release oxygen through photosynthesis, playing a critical role in maintaining atmospheric balance. They act as carbon sinks, helping to mitigate climate change and providing essential oxygen for life on Earth.
Fill in the Blanks:
(a) The roots of trees in a forest help prevent soil erosion and waterlogging.
(b) Transpiration and evaporation are two key processes in the water cycle facilitated by forests.
Conservation Strategies:
Methods for Conserving Forests:
Effective methods include afforestation (planting new trees), promoting sustainable forestry practices, creating protected areas, and raising public awareness. Forest conservation is crucial for maintaining biodiversity, ecological balance, and environmental health.
Also Check – Afforestation vs. Deforestation -The Key Differences Explained
Scenario-Based Question:
Impacts of Deforestation:
Significant deforestation leads to habitat loss, reduced biodiversity, altered microclimates, increased soil erosion, and disruption of the water cycle. It can also exacerbate climate change by releasing stored carbon dioxide.
Discussion-Based Questions
Biodiversity in Forests and Ecological Balance:
Biodiversity in forests is vital for ecological balance. It ensures the stability of ecosystems, provides a variety of resources, and supports services like pollination and decomposition. Protecting biodiversity is essential for sustaining forest ecosystems and the overall health of our planet.
Worksheet 3 – Chapter 12 – Forests: Our Lifeline – Student Worksheet (Unsolved)
Role of Forests in Ecology:
(a) Explain the significance of forests in the regulation of the Earth’s climate.
(b) Describe how forests contribute to the water cycle.
Forest Biodiversity:
(a) Discuss the importance of biodiversity within a forest ecosystem.
(b) What are the roles of different animal types (herbivores, carnivores, omnivores) in maintaining forest biodiversity?
True or False – Provide Explanations:
(a) Deforestation has no significant impact on local wildlife. (T/F)
(b) Forests act as natural carbon sinks, helping to reduce global warming. (T/F)
Multiple Choice Questions:
(a) Which layer of a forest is crucial for supporting the majority of animal life?
(i) Canopy
(ii) Understorey
(iii) Forest floor
(iv) Herb layer
(b) The process by which plants convert light energy into chemical energy is known as:
(i) Respiration
(ii) Photosynthesis
(iii) Decomposition
(iv) Transpiration
Environmental Impact:
Explain how forests play a role in maintaining soil quality and preventing soil erosion.
Fill in the Blanks:
(a) The __________ of trees in forests helps to maintain the water table.
(b) Forests are home to a wide variety of __________, which are crucial for pollination and seed dispersal.
Analysing Human Impact:
Discuss the consequences of deforestation on local and global scales.
Scenario-Based Question:
If a large section of a forest is destroyed by fire, what immediate and long-term effects might this have on the local ecosystem?
Discussion-Based Questions
Discuss the role of forest conservation efforts and how individuals and communities can contribute to preserving forests.
Worksheet 3 – Chapter 12 – Forests: Our Lifeline – Solved Worksheet with Answer
Role of Forests in Ecology:
(a) Significance in Climate Regulation:
Forests play a crucial role in regulating the Earth’s climate by absorbing carbon dioxide during photosynthesis, thus reducing greenhouse gases. They also influence local climate conditions by maintaining humidity and temperature levels, essential for various life forms.
(b) Contribution to the Water Cycle:
Forests contribute to the water cycle through transpiration, where water is released from leaves into the atmosphere, and through their role in rain formation. Forests also help in maintaining the water table and preventing soil erosion, which is vital for water conservation.
Forest Biodiversity:
(a) Importance of Biodiversity:
Biodiversity in forests ensures ecological balance and resilience. It supports a variety of life forms, each playing a role in food webs, nutrient cycling, and ecosystem services like pollination and seed dispersal.
(b) Roles of Animal Types:
Herbivores aid in seed dispersal and maintain vegetation by feeding on plants. Carnivores control the population of herbivores, preventing overgrazing. Omnivores contribute to both plant and animal food chains and help in maintaining ecological balance.
True or False – Provide Explanations:
(a) Deforestation has no significant impact on local wildlife. (F) – Deforestation leads to habitat loss, threatening wildlife populations and biodiversity.
(b) Forests act as natural carbon sinks, helping to reduce global warming. (T) – Forests absorb carbon dioxide, a major greenhouse gas, reducing the impact of global warming.
Multiple Choice Questions:
(a) Function of Humus in Forest Soil:
Answer: (ii) Enhancing soil fertility – Humus, formed from decomposed organic matter, enriches the soil, providing essential nutrients for plant growth.
(b) Component Crucial for Nutrient Cycling:
Answer: (iii) Decomposers – Organisms like fungi and bacteria break down dead matter, releasing nutrients back into the soil, vital for forest sustainability.
Environmental Impact:
Role of Forests in Soil Quality and Erosion Prevention:
Forests enhance soil quality by contributing organic matter and nutrients through the decomposition process. The roots of trees bind the soil, reducing erosion, especially during heavy rains, and maintaining soil integrity.
Fill in the Blanks:
(a) The roots of trees in forests help prevent soil erosion and flooding.
(b) Transpiration and evaporation are two key processes in the water cycle facilitated by forests.
Analysing Human Impact:
Consequences of Deforestation:
Deforestation leads to loss of biodiversity, disruption of ecosystems, soil erosion, reduced rainfall, increased carbon dioxide levels in the atmosphere, and climate change. It can also have direct human impacts, like reduced availability of forest products and altered local weather patterns.
Scenario-Based Question:
Effects of Forest Fire on Ecosystem:
Immediate effects include loss of habitat, decreased air quality, and death of wildlife. Long-term impacts are loss of biodiversity, increased soil erosion, disrupted water cycles, and potential desertification. Recovery can take decades, depending on the severity of the fire.
Discussion-Based Questions
Role of Forest Conservation:
Forest conservation is vital for maintaining ecological balance, preserving biodiversity, and combating climate change. Efforts include sustainable forestry, reforestation, protecting existing forests, and raising awareness about the importance of forests. Communities and individuals can contribute by supporting conservation initiatives, reducing paper and wood consumption, and advocating for policies that protect forests.
Worksheet 4 – Chapter 12 – Forests: Our Lifeline – Student Worksheet (Unsolved)
Understanding Forests:
(a) Define a forest and explain its role as a complete ecosystem.
(b) Describe the different kinds of forests and their distribution based on geographical and climatic conditions.
Forest Composition:
(a) List the various plant species found in forests and their importance.
(b) Explain the process of natural forest growth and the environmental conditions that support it.
True or False – Justify Your Answer:
(a) Only living organisms form part of a forest ecosystem. (T/F)
(b) All layers of a forest receive an equal amount of sunlight. (T/F)
Multiple Choice Questions:
(a) What is ‘humus’ and its role in a forest?
(i) A type of tree
(ii) A layer of the forest floor
(iii) Decayed organic matter enriching the soil
(iv) A species of decomposer
(b) Which layer of a forest is most dense and rich in biodiversity?
(i) The canopy
(ii) The understorey
(iii) The forest floor
(iv) The emergent layer
Role of Forests in Environmental Balance:
Discuss the role of forests in maintaining the balance of oxygen and carbon dioxide in the atmosphere, referring to them as ‘green lungs.’
Fill in the Blanks:
(a) Forests help in preventing floods and soil erosion due to the __________ of trees.
(b) __________ is a process where plants release water vapour into the atmosphere, contributing to the water cycle.
Importance of Forests:
Elaborate on the significance of forests in providing habitat, regulating climate, and supporting biodiversity.
Scenario-Based Question:
What would be the impact on the local environment and biodiversity if a section of a forest is cleared for urban development?
Discussion-Based Questions
Discuss the importance of afforestation and the consequences of deforestation on the environment and biodiversity.
Worksheet 4 – Chapter 12 – Forests: Our Lifeline – Solved Worksheet with Answer
Understanding Forests:
(a) Definition and Role as Ecosystem:
A forest is a large area covered with trees and a wide variety of plants, forming a complete ecosystem. It supports numerous living organisms, including trees, shrubs, plants, microorganisms, wild animals, and birds. Forests also include abiotic factors like sunlight, air, nutrients, water, and rocks. They play a crucial role in maintaining ecological balance, providing habitats, and supporting diverse life forms.
(b) Different Kinds of Forests:
There are various types of forests, such as tropical rainforests, temperate forests, and boreal forests. Their distribution depends on geographical and climatic conditions. Tropical rainforests are found near the equator, temperate forests in temperate zones, and boreal forests in the northern latitudes. Each type of forest has unique characteristics and biodiversity.
Forest Composition:
(a) Plant Species and Importance:
Forests are home to numerous plant species like Neem, bamboo, Sheesham, fig, sal, amla, and teak. These plants provide essential resources for the environment and human beings, including oxygen, food, and shelter. They contribute to the ecological balance and support diverse wildlife.
(b) Natural Forest Growth:
Forests grow naturally without the need for human intervention. They offer favourable environmental conditions for plants to germinate and grow, such as adequate sunlight, water, and nutrients. This natural growth process contributes to the forest’s sustainability and biodiversity.
True or False – Justifications:
(a) Only living organisms form part of a forest ecosystem. (F) – A forest ecosystem consists of both living organisms and non-living or abiotic factors such as sunlight, air, nutrients, water, and rocks.
(b) All layers of a forest receive an equal amount of sunlight. (F) – Different layers of the forest receive varying amounts of sunlight. The canopy layer gets the most sunlight, while the understorey and forest floor receive less due to shading by upper layers.
Multiple Choice Questions:
(a) Role of Humus:
Answer: (iii) Decayed organic matter enriching the soil – Humus, made from dead and decaying organisms, enriches the soil by providing nutrients and improving its structure.
(b) Most Dense and Rich Layer in Biodiversity:
Answer: (i) The canopy – The canopy layer is the most dense and rich in biodiversity, hosting a variety of plant and animal life.
Role of Forests in Environmental Balance:
Balancing Oxygen and Carbon Dioxide:
Forests, often referred to as ‘green lungs,’ play a vital role in maintaining the balance of oxygen and carbon dioxide in the atmosphere. Through photosynthesis, trees and plants in forests absorb carbon dioxide and release oxygen, providing fresh air and helping to regulate the Earth’s climate.
Fill in the Blanks:
(a) Forests help in preventing floods and soil erosion due to the roots of trees.
(b) Transpiration is a process where plants release water vapour into the atmosphere, contributing to the water cycle.
Importance of Forests:
Significance in Habitat, Climate, and Biodiversity:
Forests are crucial for providing habitats to a wide range of species, regulating climate, and supporting biodiversity. They offer a natural habitat for animals and plants, help in regulating the amount of oxygen and carbon dioxide, prevent global warming, regulate the water cycle, and prevent various forms of pollution.
Scenario-Based Question:
Impact of Forest Clearing:
Clearing a section of a forest for urban development can lead to loss of biodiversity, disruption of ecosystems, increased soil erosion, changes in local climate, and a decline in air and water quality. It can also affect the livelihoods of people who depend on the forest for resources.
Discussion-Based Questions
Importance of Afforestation and Consequences of Deforestation:
Afforestation, the process of planting trees in unproductive areas, is vital for improving the environment and providing the benefits that forests offer. In contrast, deforestation leads to loss of biodiversity, changes in climate, disturbed water cycles, increased air pollution, and potential floods. It’s crucial to balance human development with forest conservation to maintain ecological harmony.
