Samacheer Kalvi Class 6 Science Solutions Term 3 Chapter 4 Our Environment

Samacheer Kalvi 6th Science Our Environment Text Book Back Questions and Answers

I. Choose the correct answer:

 

Question 1. Identify the freshwater ecosystem.
(a) Pond
(b) Lake
(c) River
(d) All of the options
Answer: (d) All of the options
In simple words: All the options listed—pond, lake, and river—are examples of freshwater ecosystems. These are water bodies that do not contain salt.

🎯 Exam Tip: Remember that freshwater ecosystems include various types like ponds, lakes, rivers, and streams, each with its unique characteristics but sharing the common feature of low salinity.

 

Question 2. Producers are ________.
(a) Animals
(b) Birds
(c) Plants
(d) Snakes
Answer: (c) Plants
In simple words: Plants are called producers because they make their own food using sunlight. Animals, birds, and snakes all eat other things to get energy.

🎯 Exam Tip: Always remember that producers form the base of every food chain as they convert sunlight into energy, making it available for other organisms.

 

Question 3. It is a biodegradable waste.
(a) Plastic
(b) Coconut Shell
(c) Glass
(d) Aluminium
Answer: (b) Coconut Shell
In simple words: A coconut shell can break down naturally over time. Things like plastic, glass, and aluminum do not break down easily and stay in the environment for a very long time.

🎯 Exam Tip: Biodegradable waste can be naturally decomposed by microorganisms, whereas non-biodegradable waste cannot. Identifying these correctly is important for waste management.

 

Question 4. It is an undesirable change that occurs in air and water.
(a) Recycling
(b) Reuse
(c) Pollution
(d) Reduce
Answer: (c) Pollution
In simple words: Pollution means harmful changes happen in the air or water. Recycling, reuse, and reduce are good actions that help the environment, not undesirable changes.

🎯 Exam Tip: Understand that pollution refers to the introduction of contaminants that harm the environment, contrasting with solutions like recycling, reuse, and reduction which help protect it.

 

Question 5. Usage of chemical pesticides and fertilisers causes ________ pollution.
(a) Air pollution
(b) Water pollution
(c) Noise pollution
(d) None of the options
Answer: (b) Water pollution
In simple words: When farmers use too many chemicals like pesticides and fertilizers, these chemicals can wash into rivers and lakes, making the water dirty and unsafe. This is a common way that water pollution occurs.

🎯 Exam Tip: Remember that chemicals used in agriculture often flow into water bodies through rain and runoff, leading to water pollution, which can harm aquatic life and human health.

II. Fill in the Blanks

 

Question 1. Primary consumers that eat plants are called ________.
Answer: herbivores
In simple words: Animals that only eat plants are known as herbivores. They are the first level of consumers in a food chain.

🎯 Exam Tip: Classify organisms based on their diet: herbivores eat plants, carnivores eat meat, and omnivores eat both plants and meat.

 

Question 2. Temperature, light and wind are ________ factors.
Answer: physical
In simple words: Factors like temperature, light, and wind are parts of the physical environment that affect living things. They are non-living components of an ecosystem.

🎯 Exam Tip: Distinguish between biotic (living) and abiotic (non-living or physical) factors in an ecosystem, as both are crucial for its balance.

 

Question 3. ________ is the process of converting waste materials into new materials.
Answer: Recycle
In simple words: Recycling takes old waste items and turns them into something new and useful. This helps reduce trash and saves natural resources.

🎯 Exam Tip: Recycling is a key part of waste management, reducing landfill waste and conserving resources by creating new products from used materials.

 

Question 4. Water pollution can spread ________ and chemicals.
Answer: diseases
In simple words: When water gets polluted, it can carry sicknesses and harmful chemicals. Drinking or using dirty water can make people sick.

🎯 Exam Tip: Recognize that polluted water is a major health hazard, responsible for spreading various diseases and contaminating ecosystems with toxic substances.

 

Question 5. The 3R's are Reduce, ________ and Recycle.
Answer: reuse
In simple words: The three R's—Reduce, Reuse, and Recycle—are important steps we can take to manage waste better. Reusing means finding new ways to use things instead of throwing them away.

🎯 Exam Tip: The 3R's are a hierarchy for waste management, with reducing consumption being the most effective, followed by reusing items, and then recycling.

III. True or False. If False, give the correct statement.

 

Question 1. The pacific ocean is an example of an aquatic ecosystem.
Answer: True.
In simple words: The Pacific Ocean is a large body of water, so it is indeed an example of an aquatic ecosystem. It holds many types of marine life.

🎯 Exam Tip: Remember that aquatic ecosystems include oceans, seas, rivers, lakes, and ponds, covering both saltwater and freshwater environments.

 

Question 2. Bacteria and fungi are called decomposers.
Answer: True.
In simple words: Bacteria and fungi break down dead plants and animals. They are important decomposers, helping to return nutrients to the soil.

🎯 Exam Tip: Understand the role of decomposers in nutrient cycling, as they break down organic matter and make nutrients available for producers again.

 

Question 3. Human and animal wastes are examples of non-biodegradable waste.
Answer: False – Human and animal wastes are examples of biodegradable waste.
In simple words: Human and animal waste can naturally break down over time. This makes them biodegradable, unlike plastic or metal.

🎯 Exam Tip: Differentiate between biodegradable (materials that decompose naturally) and non-biodegradable (materials that do not decompose naturally or take a very long time).

 

Question 4. Excessive use of pesticides leads to air pollution.
Answer: False – Excess use of pesticides leads to land pollution.
In simple words: Using too many pesticides makes the soil dirty and harms the land. While some might go into the air, their main impact is on the soil itself and eventually water.

🎯 Exam Tip: Focus on the primary impact of pesticides, which is contaminating soil and water, though some airborne drift can occur.

 

Question 5. In schools, waste management rules say that we should separate waste in two categories.
Answer: False – In schools waste management rules say that we should separate waste in three categories.
In simple words: Schools are often taught to sort waste into three groups for better management. This usually includes wet waste, dry waste, and sometimes hazardous waste.

🎯 Exam Tip: Proper waste segregation, often into three main categories (biodegradable, non-biodegradable, and sometimes hazardous), is crucial for effective waste management.

IV. Match the following

 

Question 1. Match the following

Answer:
1. - e
2. - d
3. - b
4. - a
5. - c
In simple words: This match shows how different terms relate to elements in an ecosystem or types of pollution. For example, biotic factors are living things like animals, and sewage causes water pollution.

🎯 Exam Tip: When matching, carefully consider the definition and primary association of each term to connect them accurately.

V. Arrange the following in a correct sequence and form a food chain

 

Question 1. Arrange the following in a correct sequence and form a food chain: Rabbit → Carrot → Eagle → Snake.
Answer: carrot → rabbit → snake → eagle.
In simple words: In this food chain, the carrot is eaten by the rabbit, the rabbit is eaten by the snake, and finally, the snake is eaten by the eagle. Each animal gets energy from the one before it.

🎯 Exam Tip: A food chain always starts with a producer (like a plant) and shows the flow of energy from one organism to another, indicating who eats whom.

 

Question 2. Arrange the following in a correct sequence and form a food chain: Human → Insect → Algae → Fish.
Answer: Algae → Insect → Fish → Human
In simple words: This food chain begins with algae, which is eaten by an insect. The insect is then eaten by a fish, and the fish is eaten by a human. This shows energy moving from the smallest living things to humans.

🎯 Exam Tip: Always start your food chain with a producer (like algae or plants) and follow the arrows to show how energy is transferred to consumers.

VI. Give Very Short Answer:

 

Question 1. Define ecosystem.
Answer: An ecosystem is a community of living (biotic) things and non-living (abiotic) things that work together in a particular area. These parts depend on each other for survival and balance. For example, a forest includes trees, animals, soil, water, and sunlight all interacting.
In simple words: An ecosystem is a group of living things and non-living things in an area that all interact and depend on each other.

🎯 Exam Tip: When defining "ecosystem," always mention both biotic (living) and abiotic (non-living) components and their interaction.

 

Question 2. What are the two types of ecosystems?
Answer: The two main types of ecosystems are terrestrial and aquatic. Terrestrial ecosystems are found on land, like forests or deserts. Aquatic ecosystems are found in water, like oceans, lakes, or rivers.
In simple words: The two types of ecosystems are land-based (terrestrial) and water-based (aquatic).

🎯 Exam Tip: Clearly state and give a simple example for each of the two major ecosystem types: terrestrial (land) and aquatic (water).

 

Question 3. Write any two things that can be recycled.
Answer: Two things that can be recycled are old clothes and plastics. Recycling these items helps reduce waste and saves resources needed to make new products. For instance, old clothes can be turned into new fabrics or insulation, and plastics can be melted down to create new plastic items.
In simple words: Old clothes and plastics are two items that can be recycled to make new things.

🎯 Exam Tip: When asked for examples of recyclable items, think of common household waste that can be processed and reused, like paper, plastic, glass, or metal.

 

Question 4. What are the types of pollution?
Answer: There are four major kinds of pollution: air pollution, water pollution, land (soil) pollution, and noise pollution. Each type harms the environment in different ways, affecting living beings and natural resources.
In simple words: The main types of pollution are air, water, land (soil), and noise pollution.

🎯 Exam Tip: List the four primary types of pollution clearly: air, water, land, and noise. Briefly consider what causes each type to deepen your understanding.

 

Question 5. Give one example of a food chain in an aquatic ecosystem?
Answer: An example of a food chain in an aquatic ecosystem is: Aquatic plant → Aquatic insect → Larva → Fish. In this chain, the aquatic plant is eaten by the aquatic insect, which is then eaten by the larva, and finally, the fish eats the larva, showing the flow of energy. Aquatic plants, like algae, are often the producers in water.
In simple words: An aquatic food chain example is: aquatic plant, then aquatic insect, then larva, and finally fish.

🎯 Exam Tip: When giving an example of a food chain, ensure it starts with a producer and shows a clear, sequential transfer of energy between organisms.

 

Question 6. Name some pollutants.
Answer: Some common pollutants include burning fossil fuels (like petrol, coal, and oil), toxic gases (such as carbon monoxide), and dust particles (like ash and soot). These substances harm the environment when released into the air, water, or land. Industrial waste is another major source.
In simple words: Some pollutants are burning fossil fuels, toxic gases like carbon monoxide, and dust particles.

🎯 Exam Tip: Identify common substances or activities that release harmful agents into the environment, such as industrial emissions, vehicle exhaust, and waste products.

 

Question 7. What are the pollutions caused by the objects given below?
1. Loud Speaker
2. Plastic
Answer:
1. Loud Speaker – Noise Pollution. Excessive use of loud speakers creates unwanted noise, which is harmful to human health and disturbs animals.
2. Plastic - Land Pollution. Plastics do not break down easily and accumulate on land, harming soil quality and animal life.
In simple words: Loud speakers cause noise pollution, and plastics cause land pollution.

🎯 Exam Tip: Connect specific objects or activities directly to the type of pollution they primarily cause (e.g., loud sounds to noise, non-biodegradable waste to land).

VII. Give a short answer:

 

Question 1. What is biodegradable waste?
Answer: Biodegradable waste refers to things that can easily break down into simpler substances by natural processes. This happens with the help of natural agents like water, oxygen, sunlight, and tiny living things called microorganisms. Examples include vegetable and fruit peels, leftover food, grass, leaves, and twigs, all of which return nutrients to the soil.
In simple words: Biodegradable waste is trash that can be naturally broken down by tiny living things and natural elements like water and sun.

🎯 Exam Tip: A good definition of biodegradable waste should include its ability to be decomposed by natural agents and microorganisms, along with common examples.

 

Question 2. How can we reduce water pollution?
Answer: We can reduce water pollution by taking several important steps. First, we should not pour leftover oil, old medicines, or waste down drains or into the toilet. Second, reducing the use of chemical pesticides and fertilizers in farming helps prevent runoff into water bodies. Third, using fewer detergents and less bleach when washing clothes decreases chemical discharge. Finally, always putting litter or dump waste into a proper waste bin, rather than discarding it carelessly, prevents pollutants from reaching water sources. These actions help keep our water clean and safe.
In simple words: To reduce water pollution, don't dump oil or medicines, use fewer farm chemicals, use less soap, and always put trash in bins.

🎯 Exam Tip: When suggesting ways to reduce pollution, provide actionable and practical examples that people can follow in their daily lives.

 

Question 3. Write the importance of the food chain.
Answer: The food chain is very important for several reasons. Firstly, learning about the food chain helps us understand how different organisms are connected through feeding relationships and how they interact within an ecosystem. Secondly, it allows us to see how energy flows and nutrients move from one part of the ecosystem to another. This understanding is key to grasping how toxic substances can move through the environment and affect various organisms, including humans. By tracing these connections, we can better appreciate the delicate balance of nature.
In simple words: The food chain shows how living things eat each other for energy. It helps us understand how nutrients move and how harmful things can spread in nature.

🎯 Exam Tip: Highlight two main points for the importance of food chains: understanding feeding relationships and appreciating energy flow and nutrient circulation within an ecosystem.

VIII. Answer in detail:

 

Question 1. Give two examples of how you can avoid or reduce waste?
Answer: Here are two ways to avoid or reduce waste:
1. To avoid waste, we can stop buying packaged foods and refuse 'use-and-throw' plastic products. Choosing items with less packaging or reusable alternatives helps a lot. For example, carrying your own cloth bag for shopping reduces the need for plastic bags.
2. To reduce waste, we can write on both sides of paper and share newspapers and magazines with others instead of throwing them away. This simple act doubles the life of paper and cuts down on consumption. Buying things in bulk can also reduce packaging waste.
In simple words: Avoid buying packaged and 'use-and-throw' items. Reduce waste by writing on both sides of paper and sharing magazines.

🎯 Exam Tip: Focus on practical actions like refusing single-use plastics and maximizing the utility of items to illustrate waste avoidance and reduction.

 

Question 2. Write a short note on noise pollution.
Answer: Noise pollution is when loud or unpleasant sounds disturb the environment, affecting living beings. We all prefer a quiet and peaceful place, but noisy areas can be very disturbing. Loud music, sounds from motor vehicles, fireworks, and machines are common causes of noise pollution. This continuous noise can harm our health, leading to stress, high blood pressure, hearing loss, and disturbed sleep. It also affects animals, forcing birds to communicate louder and confusing aquatic animals like whales. Reducing noise pollution involves turning off unused electronics, avoiding fireworks, speaking softly, asking drivers not to honk excessively, and lowering the volume of TV or music. Creating quieter environments is crucial for our well-being and that of wildlife.
In simple words: Noise pollution is harmful loud sounds that bother people and animals. It's caused by things like loud music, vehicles, and fireworks. It can cause stress, hearing problems, and disturb sleep. We can reduce it by being quieter and turning off loud devices.

🎯 Exam Tip: In your note on noise pollution, include its definition, common sources, negative impacts on both humans and animals, and practical ways to reduce it.

IX. Questions Based on Higher Order Thinking Skills

 

Question 1. What would happen if an organism is removed from the food chain?
Answer: If an organism is removed from a food chain, the entire ecosystem can become imbalanced and eventually collapse.
1. First, the food chain will fall apart because the flow of energy is broken.
2. Then, the ecosystem will become unstable and may collapse.
3. For example, consider a food chain: Plants → grasshoppers → frogs → snakes → hawks. If frogs were to die off in this chain, perhaps due to a disease or pollutants, then two main things would happen. First, the number of grasshoppers would increase greatly because their predators (frogs) are gone. Second, the snakes, which eat frogs, would have less food and their population would decrease. This imbalance can cause big problems for the whole environment. Every organism plays a vital role in maintaining the balance of an ecosystem.
In simple words: If one animal is removed from a food chain, the whole system gets upset. Animals that eat it will have less food, and animals it ate will grow too much, causing a big imbalance.

🎯 Exam Tip: When explaining the impact of removing an organism, describe the effects on both the trophic level below (its prey population increases) and the trophic level above (its predator population decreases).

 

Question 2. Explain the link between waste and dangerous diseases like dengue and malaria?
Answer: There is a strong link between waste, especially unmanaged waste, and dangerous diseases like dengue and malaria.
1. Many waste materials, such as plastic, metal scraps, aluminum cans, and bottles, are non-biodegradable, meaning they do not break down in the soil naturally.
2. When it rains, water often collects in these discarded items in garbage dumps, forming small pools.
3. These tiny pools of stagnant water provide perfect breeding grounds for mosquitoes, which then spread diseases.
4. Specifically, the Aedes aegypti mosquito is known to carry the dengue virus, and it often breeds in water collected in solid waste like mud pots and other junk.
5. We must understand that mosquitoes thrive in dirty, stagnant water, making proper waste management essential to prevent these diseases. Therefore, keeping our surroundings clean is crucial for public health.
In simple words: Waste, especially plastic and metal, collects rainwater. These small water pools are perfect places for mosquitoes, like the Aedes aegypti, to lay eggs. These mosquitoes then spread dangerous diseases like dengue and malaria.

🎯 Exam Tip: Clearly connect unmanaged non-biodegradable waste to stagnant water, then to mosquito breeding, and finally to the transmission of diseases like dengue and malaria.

X. See the diagram and answer the following questions:

 

Question 1. Explain what is happening in the picture?

Answer: The picture shows an open dump where mixed waste has been thrown onto the ground.
1. We can see a fire burning within the garbage, and smoke along with toxins are rising into the air, causing air pollution.
2. The leftover ash from this burning waste also pollutes the soil.
3. Furthermore, when it rains, dangerous chemicals from the garbage seep into the soil and groundwater, leading to soil and water pollution. This entire scene illustrates how unhealthy chemicals from the garbage severely pollute the ecosystem.
In simple words: The picture shows a garbage dump on fire, releasing smoke and bad chemicals into the air. Rain washes more chemicals from the trash into the soil and water, making everything polluted.

🎯 Exam Tip: When analyzing diagrams, identify all key elements and processes shown (e.g., waste, fire, smoke, leaching) and explain their environmental consequences.

 

Question 2. What types of pollution are caused by open dumps?
Answer: Open dumps cause multiple types of pollution, which seriously harm the environment. The main types of pollution caused are:
1. Water pollution: Rainwater seeps through the garbage, carrying harmful chemicals into the groundwater and nearby water bodies.
2. Land pollution: The waste directly contaminates the soil, making it toxic and unfit for plant growth. Leftover ash from burning waste also pollutes the soil.
3. Air pollution: Burning garbage in open dumps releases smoke, toxic gases, and small particles into the air, which are very harmful to breathe. This can cause various respiratory problems. Open dumps are significant contributors to environmental degradation.
In simple words: Open dumps cause water pollution (chemicals seeping into water), land pollution (dirtying the soil), and air pollution (from burning garbage and releasing smoke).

🎯 Exam Tip: Remember that open dumps are sources of multiple environmental problems, so identify at least three types of pollution (air, water, and land) when discussing their impact.

Samacheer Kalvi 6th Science Our Environment Additional Important Questions and Answers

I. Choose the best Answer:

 

Question 1. The ecosystem that originated without human intervention is called
(a) natural ecosystem
(b) artificial ecosystem
(c) aquarium
(d) terrarium
Answer: (a) natural ecosystem
In simple words: A natural ecosystem is one that exists on its own without people creating or changing it, like a forest or an ocean.

🎯 Exam Tip: Distinguish between natural ecosystems (formed by nature) and artificial ecosystems (created or significantly modified by humans).

 

Question 2. An example for artificial aquatic ecosystem is ________
(a) Forest
(b) Pond
(c) Garden
(d) Aquarium
Answer: (d) Aquarium
In simple words: An aquarium is a water environment made and looked after by people. Forests, ponds, and gardens can be natural, though gardens are also often man-made.

🎯 Exam Tip: An artificial ecosystem is one created or managed by humans. An aquarium is a classic example of a man-made aquatic environment.

 

Question 3. Ecosystems created and maintained by humans are called?
(a) lake
(b) river
(c) artificial ecosystem
(d) natural ecosystem
Answer: (c) artificial ecosystem
In simple words: When people build or take care of an ecosystem, it is called an artificial ecosystem. Lakes and rivers are typically natural, while ponds can be both.

🎯 Exam Tip: Remember that "artificial" implies human creation or significant intervention, differentiating it from naturally occurring ecosystems.

 

Question 4. Plants are producers because they make their own food by ________
(a) Respiration
(b) Consumer
(c) Photosynthesis
(d) Decomposing
Answer: (c) Photosynthesis
In simple words: Plants use sunlight, water, and air to make their own food through a process called photosynthesis. This is why they are called producers.

🎯 Exam Tip: Photosynthesis is the fundamental process by which producers convert light energy into chemical energy, forming the base of most food chains.

 

Question 5. The micro-organisms that obtain energy from the chemical breakdown of dead organisms is called
(a) consumers
(b) decomposers
(c) omnivores
(d) producers
Answer: (b) decomposers
In simple words: Tiny living things like bacteria and fungi that break down dead plants and animals are called decomposers. They help recycle nutrients back into the environment.

🎯 Exam Tip: Decomposers play a crucial role in nutrient cycling by breaking down dead organic matter, preventing waste buildup, and returning essential nutrients to the soil.

II. True or False. If False, Give the correct statement.

 

Question 1. The abiotic factors are the non-living parts such as sunlight, air, water, and minerals in the soil.
Answer: True
In simple words: Abiotic factors are indeed the non-living things in an ecosystem, like sunlight, air, water, and soil minerals. These factors are important for living things.

🎯 Exam Tip: Be able to identify and list common abiotic factors (e.g., temperature, light, water, soil type) and understand their impact on an ecosystem.

 

Question 2. A Zoo is a natural ecosystem.
Answer: False – A Zoo is an artificial ecosystem.
In simple words: A zoo is built and managed by humans, not formed naturally. Therefore, it is an artificial ecosystem.

🎯 Exam Tip: Remember that any environment created or heavily managed by humans, like a zoo or a farm, is considered an artificial ecosystem.

 

Question 3. A food web is very useful to show the many different feeding relationships between different species within an ecosystem.
Answer: True
In simple words: A food web shows how many different plants and animals eat each other in a complex way. It is more detailed than a simple food chain.

🎯 Exam Tip: Understand that a food web is more complex and realistic than a food chain, illustrating multiple feeding pathways and interconnections within an ecosystem.

 

Question 4. India produces 532 million kilos of solid waste every day.
Answer: True
In simple words: India generates a very large amount of solid waste daily, estimated at 532 million kilograms. This highlights a significant challenge in waste management.

🎯 Exam Tip: Remember key statistics related to environmental issues when they are provided, as they demonstrate the scale of the problem.

 

Question 5. Certain toxic gases from industries mix with raindrops and make rain unusually acidic.
Answer: True
In simple words: Harmful gases from factories can mix with water in the air. When this water falls as rain, it becomes acid rain, which is bad for plants and buildings.

🎯 Exam Tip: Connect industrial emissions of toxic gases (like sulfur dioxide and nitrogen oxides) directly to the formation of acid rain, which has harmful environmental effects.

III. Match the Following:

 

Question 1. Match the Following:

Answer:
1. - d
2. - a
3. - e
4. - c
5. - b
In simple words: This match connects terms to their definitions or roles. Edaphic factor relates to soil, snails are primary consumers, crows are omnivores, earthworms are decomposers, and hazardous chemicals are non-biodegradable.

🎯 Exam Tip: Review each term and its definition to ensure accurate matching. For example, "edaphic" always refers to soil properties.

IV. Arrange the following statements in the correct sequence and form a food chain:

 

Question 1. Arrange the following statements in the correct sequence and form a food chain: Grasshopper → Frog → Grass → Crow.
Answer: Grass → Grasshopper → Frog → Crow
In simple words: In this food chain, grass is eaten by the grasshopper. The grasshopper is then eaten by the frog, and finally, the crow eats the frog. This shows how energy moves through different animals.

🎯 Exam Tip: Always start a food chain with the producer (plant) and follow the direction of energy flow to the primary, secondary, and tertiary consumers.

 

Question 2. Arrange the following statements in the correct sequence and form a food chain: Peacock → Rat → Grains → Snake
Answer: Grains → Rat → Snake → Peacock
In simple words: This food chain starts with grains, which are eaten by the rat. The rat is then eaten by the snake, and finally, the snake is eaten by the peacock. Each step shows who eats whom.

🎯 Exam Tip: Ensure that the sequence accurately reflects who consumes whom, starting from the food source (producer) and moving up the chain.

V. Very Short Answer:

 

Question 1. Give two examples of artificial terrestrial ecosystems?
Answer: Two examples of artificial terrestrial ecosystems are paddy fields and gardens. Both are created and managed by humans for specific purposes, such as growing food or cultivating plants for beauty. While they exist on land, their structure and components are heavily influenced by human intervention. Farms are another excellent example.
In simple words: Two examples of man-made land ecosystems are paddy fields (for rice) and gardens.

🎯 Exam Tip: Artificial terrestrial ecosystems are those on land that have been significantly altered or created by human activities, like agricultural lands or landscaped parks.

Vi. Answer In Detail:

 

Question 1. How do we reduce noise pollution?
Answer: We can reduce noise pollution by several actions. Firstly, turn off electronic devices like TVs and radios when not in use. Secondly, keep the volume low when watching TV or listening to music. Thirdly, remind drivers to avoid honking their horns excessively. Additionally, we should stay away from fireworks, as they create very loud noises. Lastly, remember to speak softly instead of shouting. A quieter environment is beneficial for everyone's health and well-being.
In simple words: To make things less noisy, turn off unused electronics, keep music low, tell drivers not to honk too much, avoid fireworks, and speak quietly.

🎯 Exam Tip: List specific, actionable steps when asked how to reduce environmental problems. Focus on daily habits that make a difference.

 

Question 2. Differentiate the artificial ecosystem and natural ecosystem.
Answer: A natural ecosystem is one that forms by itself without any help from people. Examples include vast oceans, flowing rivers, large lakes, and dense forests. These ecosystems are shaped by natural processes and species interactions. In contrast, an artificial ecosystem is created and maintained by humans. Good examples are paddy fields where rice is grown, home gardens, and aquariums. People design these to suit specific purposes.
In simple words: Natural ecosystems happen on their own, like forests and rivers. Artificial ecosystems are made by people, such as farms or gardens.

🎯 Exam Tip: When asked to differentiate, provide clear definitions and distinct examples for each category. Use a comparative approach to highlight differences.

Vii. Questions Based On Higher-Order Thinking Levels:

 

Question 1. Are animal bones biodegradable?
Answer: Yes, animal bones are biodegradable, meaning they can break down over time. Tiny living things called microorganisms, like bacteria and fungi, help to decompose bones in the soil. This process happens faster in warm and moist places, where bones might break down in about ten years. However, in dry places, it can take thousands of years for bones to fully decay. The calcium in bones needs specific conditions to break down, unlike softer tissues.
In simple words: Yes, animal bones can break down naturally. Microbes help them decay, but it takes a long time, especially in dry places.

🎯 Exam Tip: When explaining biodegradability, mention the conditions that affect decomposition speed, like temperature and moisture, as they are key factors.

 

Question 2. Are all types of clothes biodegradable?
Answer: No, not all types of clothes are biodegradable. Whether a fabric can break down naturally depends on what it is made from. Many clothes today use man-made or chemical materials, which do not decompose easily. For example, natural fibers like cotton, silk, and hemp are biodegradable. However, fabrics like polyester, which is a type of plastic called a polymer, do not break down in nature. This is why choosing clothes made from natural fibers is better for the environment.
In simple words: No, not all clothes break down easily. Natural clothes like cotton do, but synthetic ones like polyester do not because they are made from plastic.

🎯 Exam Tip: When discussing biodegradability of clothes, highlight the difference between natural fibers (like cotton, silk) and synthetic fibers (like polyester) and their environmental impact.