Our Environment

What is an ecosystem?
a) A collection of only animals in a region
b) A system where living and non-living components interact
c) A group of planets
d) A process of food production
Answer: b) A system where living and non-living components interact

Which of the following is a natural ecosystem?
a) Aquarium
b) Garden
c) Pond
d) Crop field
Answer: c) Pond

What is the role of producers in an ecosystem?
a) Consume food from other organisms
b) Produce food using sunlight and inorganic substances
c) Break down organic material
d) Pollinate flowers
Answer: b) Produce food using sunlight and inorganic substances

What do decomposers do in an ecosystem?
a) Consume plants directly
b) Break down dead organisms into simpler substances
c) Protect the ozone layer
d) Increase soil salinity
Answer: b) Break down dead organisms into simpler substances

Which of the following is an example of a producer?
a) Deer
b) Algae
c) Eagle
d) Fungi
Answer: b) Algae

In a food chain, what comes after the producer?
a) Primary consumers
b) Tertiary consumers
c) Decomposers
d) Scavengers
Answer: a) Primary consumers

What is the flow of energy in an ecosystem?
a) Cyclical
b) Unidirectional
c) Random
d) Bidirectional
Answer: b) Unidirectional

What percentage of solar energy is captured by green plants in a terrestrial ecosystem?
a) 1%
b) 10%
c) 20%
d) 50%
Answer: a) 1%

What happens to energy as it moves through trophic levels?
a) It increases
b) It remains constant
c) It decreases
d) It disappears completely
Answer: c) It decreases

Why are food chains generally limited to 3-4 steps?
a) Energy loss at each step reduces availability
b) There are not enough organisms
c) Food chains must be short by rule
d) Predators prevent further steps
Answer: a) Energy loss at each step reduces availability

What is a food web?
a) A single food chain
b) A network of interconnected food chains
c) A type of artificial ecosystem
d) A system that recycles nutrients
Answer: b) A network of interconnected food chains

What is biological magnification?
a) Increasing food availability at each trophic level
b) Accumulation of harmful substances at higher trophic levels
c) Increase in the population of consumers
d) Decrease in decomposers in the ecosystem
Answer: b) Accumulation of harmful substances at higher trophic levels

What causes biological magnification?
a) Excess nutrients in soil
b) Non-biodegradable chemicals like pesticides
c) Overgrowth of producers
d) Natural disasters
Answer: b) Non-biodegradable chemicals like pesticides

What is ozone (O3)?
a) A toxic gas harmful at ground level
b) A molecule essential for plant growth
c) A shield against UV radiation in the atmosphere
d) A gas that supports combustion
Answer: c) A shield against UV radiation in the atmosphere

What is the main cause of ozone layer depletion?
a) Excess oxygen in the atmosphere
b) Use of chlorofluorocarbons (CFCs)
c) Deforestation
d) Overuse of fossil fuels
Answer: b) Use of chlorofluorocarbons (CFCs)

Why is the ozone layer important?
a) It traps carbon dioxide
b) It blocks harmful UV radiation from reaching Earth
c) It helps produce oxygen
d) It prevents acid rain
Answer: b) It blocks harmful UV radiation from reaching Earth

What is meant by biodegradable?
a) Substances that can be broken down by biological processes
b) Substances that cause biological magnification
c) Substances that do not decompose easily
d) Substances that harm the soil
Answer: a) Substances that can be broken down by biological processes

Which of the following is a non-biodegradable substance?
a) Plastic
b) Fruit peels
c) Paper
d) Cotton cloth
Answer: a) Plastic

What is the main concern with non-biodegradable waste?
a) It decomposes too quickly
b) It accumulates and harms ecosystems
c) It causes biological magnification
d) It increases energy flow
Answer: b) It accumulates and harms ecosystems

What are the harmful effects of improper waste disposal?
a) Soil pollution
b) Water pollution
c) Air pollution
d) All of the above
Answer: d) All of the above

What is an artificial ecosystem?
a) Pond
b) Forest
c) Garden
d) Lake
Answer: c) Garden

Which trophic level contains herbivores?
a) First
b) Second
c) Third
d) Fourth
Answer: b) Second

Which of the following is a primary consumer?
a) Lion
b) Rabbit
c) Eagle
d) Mushroom
Answer: b) Rabbit

What is the ultimate source of energy for most ecosystems?
a) Wind
b) Sunlight
c) Water
d) Fossil fuels
Answer: b) Sunlight

What does 10% law of energy transfer state?
a) 10% of energy is lost as heat at each trophic level
b) 10% of energy is passed to the next trophic level
c) 10% of organisms survive at each trophic level
d) 10% of sunlight is absorbed by producers
Answer: b) 10% of energy is passed to the next trophic level

Which of the following is a decomposer?
a) Eagle
b) Grass
c) Fungi
d) Cow
Answer: c) Fungi

What would happen if decomposers were removed from an ecosystem?
a) Plants would grow faster
b) Nutrient cycling would stop
c) Herbivores would disappear
d) Producers would increase
Answer: b) Nutrient cycling would stop

What is the role of chlorofluorocarbons (CFCs)?
a) Absorb UV radiation
b) Destroy the ozone layer
c) Increase oxygen levels
d) Prevent greenhouse effect
Answer: b) Destroy the ozone layer

Which of the following is not a food chain?
a) Grass → Grasshopper → Frog → Snake
b) Algae → Fish → Eagle
c) Lion → Rabbit → Grass
d) Plant → Caterpillar → Bird
Answer: c) Lion → Rabbit → Grass

Which of these substances is biodegradable?
a) Metal can
b) Banana peel
c) Polythene
d) Glass bottle
Answer: b) Banana peel

What do trophic levels represent in an ecosystem?
a) Levels of nutrients
b) Levels of energy transfer
c) Levels of waste generation
d) Levels of biodiversity
Answer: b) Levels of energy transfer

Why are there more producers than consumers in an ecosystem?
a) Producers are more energy-efficient
b) Energy decreases at higher trophic levels
c) Consumers reproduce slowly
d) Producers consume sunlight
Answer: b) Energy decreases at higher trophic levels

Which is an example of biological magnification?
a) Accumulation of mercury in fish
b) Growth of plants using fertilizers
c) Increase in population of herbivores
d) Transfer of energy through food chain
Answer: a) Accumulation of mercury in fish

What is the main source of pesticides entering food chains?
a) Air pollution
b) Contaminated water and soil
c) Fossil fuel burning
d) Overpopulation
Answer: b) Contaminated water and soil

Which human activity has directly contributed to ozone layer depletion?
a) Deforestation
b) Use of plastics
c) Use of CFCs in refrigerators
d) Mining
Answer: c) Use of CFCs in refrigerators

What are the two types of waste generated by humans?
a) Organic and inorganic waste
b) Liquid and solid waste
c) Biodegradable and non-biodegradable waste
d) Recyclable and non-recyclable waste
Answer: c) Biodegradable and non-biodegradable waste

What happens to energy that is lost at each trophic level?
a) It is recycled by decomposers
b) It is lost as heat
c) It is used by producers
d) It remains unused
Answer: b) It is lost as heat

Why are biodegradable wastes better for the environment?
a) They do not break down
b) They increase the amount of plastic
c) They decompose and return nutrients to the soil
d) They do not produce energy
Answer: c) They decompose and return nutrients to the soil

What is an example of a non-biodegradable substance?
a) Cotton cloth
b) Plastic bottle
c) Apple core
d) Paper bag
Answer: b) Plastic bottle

How can we reduce the impact of waste disposal?
a) By burning waste
b) By reducing, reusing, and recycling
c) By burying non-biodegradable waste
d) By using more disposable items
Answer: b) By reducing, reusing, and recycling

What does a food chain represent?
a) Transfer of energy and nutrients
b) Reproduction of organisms
c) Types of decomposers
d) Loss of biodiversity
Answer: a) Transfer of energy and nutrients

Which of the following is the first trophic level in a food chain?
a) Carnivores
b) Producers
c) Decomposers
d) Primary consumers
Answer: b) Producers

What is the main function of decomposers?
a) Store energy
b) Absorb sunlight
c) Recycle nutrients
d) Produce oxygen
Answer: c) Recycle nutrients

What will happen if producers are removed from an ecosystem?
a) Herbivores will increase
b) Food chains will collapse
c) Decomposers will flourish
d) Energy flow will increase
Answer: b) Food chains will collapse

How can biological magnification affect humans?
a) Increases food production
b) Causes health problems due to toxic accumulation
c) Makes energy transfer efficient
d) Decreases UV radiation
Answer: b) Causes health problems due to toxic accumulation

Which of the following is a way to protect the ozone layer?
a) Plant more trees
b) Use CFC-free products
c) Increase recycling
d) Reduce carbon emissions
Answer: b) Use CFC-free products

What is the primary reason for waste management?
a) To create more landfills
b) To protect ecosystems from pollution
c) To burn waste for energy
d) To bury plastic in soil
Answer: b) To protect ecosystems from pollution

What is one way to reduce non-biodegradable waste?
a) Use plastic bags
b) Use disposable containers
c) Use biodegradable alternatives
d) Avoid recycling
Answer: c) Use biodegradable alternatives

Which of these is a human-made ecosystem?
a) Forest
b) Aquarium
c) River
d) Desert
Answer: b) Aquarium

How does ozone depletion affect human health?
a) Causes respiratory problems
b) Increases risk of skin cancer
c) Improves vision
d) Decreases food production
Answer: b) Increases risk of skin cancer

What happens to harmful chemicals in the food chain?
a) They get diluted
b) They accumulate at higher trophic levels
c) They vanish over time
d) They are destroyed by decomposers
Answer: b) They accumulate at higher trophic levels

Why are food webs more stable than food chains?
a) They have only one trophic level
b) They allow multiple pathways for energy flow
c) They reduce energy loss
d) They are shorter
Answer: b) They allow multiple pathways for energy flow

What is a major disadvantage of non-biodegradable materials?
a) They are costly
b) They do not decompose easily
c) They enhance soil fertility
d) They increase oxygen levels
Answer: b) They do not decompose easily

How does the ozone layer protect living organisms?
a) By absorbing UV radiation
b) By providing oxygen
c) By reflecting heat back into space
d) By converting UV radiation into visible light
Answer: a) By absorbing UV radiation

What is the relationship between producers and primary consumers?
a) Mutualism
b) Parasitism
c) Predator-prey
d) Food dependence
Answer: d) Food dependence

Which of the following is an example of waste management?
a) Burning waste in open areas
b) Dumping waste in rivers
c) Recycling paper
d) Burying non-biodegradable waste
Answer: c) Recycling paper

What is the cause of water pollution in aquatic food chains?
a) Algal blooms
b) Industrial waste and pesticides
c) Excess oxygen
d) High water temperatures
Answer: b) Industrial waste and pesticides

What is a trophic level?
a) A level in the energy pyramid
b) A species in an ecosystem
c) A habitat for decomposers
d) A type of food chain
Answer: a) A level in the energy pyramid

Which of the following is an example of a herbivore?
a) Frog
b) Cow
c) Eagle
d) Wolf
Answer: b) Cow

Why do non-biodegradable wastes cause harm?
a) They release harmful gases
b) They remain in the environment for a long time
c) They decrease soil nutrients
d) They block sunlight
Answer: b) They remain in the environment for a long time

Which of these is the best practice for waste disposal?
a) Open dumping
b) Incineration
c) Segregation of biodegradable and non-biodegradable waste
d) Disposing waste in water bodies
Answer: c) Segregation of biodegradable and non-biodegradable waste

What is the main source of energy for producers in an ecosystem?
a) Wind
b) Water
c) Sunlight
d) Soil nutrients
Answer: c) Sunlight

Which is an example of a carnivore?
a) Rabbit
b) Deer
c) Frog
d) Grasshopper
Answer: c) Frog

What happens when pesticides enter water bodies?
a) They improve water quality
b) They cause biological magnification
c) They increase aquatic plant growth
d) They evaporate quickly
Answer: b) They cause biological magnification

What is the main effect of deforestation on ecosystems?
a) Increased energy flow
b) Decreased biodiversity
c) Enhanced soil fertility
d) Reduction in non-biodegradable waste
Answer: b) Decreased biodiversity

What does the energy pyramid represent?
a) Equal energy at all levels
b) Decreasing energy at higher trophic levels
c) Constant energy flow
d) Unlimited energy at all levels
Answer: b) Decreasing energy at higher trophic levels

What is a key characteristic of biodegradable waste?
a) It is reusable
b) It decomposes naturally
c) It is non-toxic
d) It causes no environmental issues
Answer: b) It decomposes naturally

Which of these materials can be recycled?
a) Food waste
b) Plastic bottles
c) Metal cans
d) Both b and c
Answer: d) Both b and c

How does recycling help the environment?
a) Reduces pollution and conserves resources
b) Increases energy consumption
c) Stops biodegradation
d) Enhances plastic production
Answer: a) Reduces pollution and conserves resources

What type of organism occupies the top trophic level in a food chain?
a) Decomposer
b) Carnivore
c) Producer
d) Herbivore
Answer: b) Carnivore

What is the main component of the ozone layer?
a) Oxygen gas (O2)
b) Ozone gas (O3)
c) Carbon dioxide
d) Methane
Answer: b) Ozone gas (O3)

What is the primary cause of garbage accumulation?
a) Recycling
b) Burning waste
c) Increased consumption and disposable materials
d) Use of biodegradable materials
Answer: c) Increased consumption and disposable materials

Which of the following is an example of a food web?
a) Grass → Deer → Lion
b) Algae → Small Fish → Large Fish → Eagle
c) Multiple interconnected food chains in an ecosystem
d) Grasshopper → Frog → Snake
Answer: c) Multiple interconnected food chains in an ecosystem

What happens to energy when it flows through the food chain?
a) Energy is completely retained
b) Some energy is lost as heat
c) All energy is recycled
d) Energy increases at higher levels
Answer: b) Some energy is lost as heat

What are the harmful effects of plastics on the environment?
a) They decompose quickly
b) They release toxins when burned
c) They reduce water pollution
d) They provide nutrients to soil
Answer: b) They release toxins when burned

Which of the following is a renewable resource?
a) Plastic
b) Sunlight
c) Coal
d) Petroleum
Answer: b) Sunlight

How does ozone depletion affect aquatic life?
a) Enhances oxygen levels
b) Increases UV radiation exposure
c) Reduces water pollution
d) Improves biodiversity
Answer: b) Increases UV radiation exposure

What is an example of a natural waste treatment process?
a) Landfilling
b) Decomposition by microorganisms
c) Recycling plastics
d) Burning biodegradable waste
Answer: b) Decomposition by microorganisms

Why are disposable paper cups better than plastic cups?
a) They are cheaper
b) They decompose faster
c) They are stronger
d) They are reusable
Answer: b) They decompose faster

What is the impact of eutrophication in water bodies?
a) Increases biodiversity
b) Reduces oxygen levels
c) Improves water clarity
d) Enhances aquatic plant growth
Answer: b) Reduces oxygen levels

Which of the following is a consequence of improper sewage disposal?
a) Increased oxygen in water
b) Water pollution
c) Reduced biological magnification
d) Enhanced soil fertility
Answer: b) Water pollution

What is an example of a primary producer?
a) Fish
b) Grass
c) Rabbit
d) Hawk
Answer: b) Grass

What type of waste lasts the longest in the environment?
a) Food waste
b) Metal cans
c) Plastic bags
d) Paper
Answer: c) Plastic bags

How does deforestation impact the carbon cycle?
a) Reduces carbon dioxide in the atmosphere
b) Increases carbon dioxide levels
c) Enhances soil carbon storage
d) Eliminates carbon dioxide entirely
Answer: b) Increases carbon dioxide levels

What is the role of saprophytes in nature?
a) Consume living organisms
b) Decompose dead organic matter
c) Absorb sunlight
d) Produce food
Answer: b) Decompose dead organic matter

What happens to soil fertility when decomposers are removed?
a) Fertility increases
b) Fertility decreases
c) Fertility remains unchanged
d) Decomposers have no role in soil fertility
Answer: b) Fertility decreases

What is a major disadvantage of using pesticides in agriculture?
a) They reduce crop yields
b) They cause biological magnification in food chains
c) They decrease soil aeration
d) They promote pest growth
Answer: b) They cause biological magnification in food chains

What is the role of aquatic plants in an aquarium?
a) Decompose waste
b) Provide oxygen and food
c) Remove toxins
d) Eat other organisms
Answer: b) Provide oxygen and food

What is the result of eutrophication in aquatic ecosystems?
a) Increased oxygen levels
b) Death of aquatic organisms
c) Improved biodiversity
d) Reduced water pollution
Answer: b) Death of aquatic organisms

How does plastic waste impact marine ecosystems?
a) Provides habitat for fish
b) Causes ingestion and entanglement
c) Increases biodiversity
d) Improves water quality
Answer: b) Causes ingestion and entanglement

What is the primary function of the ozone layer?
a) To reflect heat
b) To block UV radiation
c) To provide oxygen
d) To trap greenhouse gases
Answer: b) To block UV radiation

What happens to UV radiation when the ozone layer is depleted?
a) It decreases
b) It is absorbed by clouds
c) It reaches Earth’s surface in higher amounts
d) It turns into infrared radiation
Answer: c) It reaches Earth’s surface in higher amounts

Which is the best way to reduce non-biodegradable waste?
a) Burning
b) Dumping in landfills
c) Recycling
d) Disposing in water bodies
Answer: c) Recycling

What is the cause of algal blooms in water bodies?
a) Increased temperature
b) Excess nutrients from fertilizers
c) Lack of sunlight
d) Reduced aquatic plant growth
Answer: b) Excess nutrients from fertilizers

How can humans help in protecting ecosystems?
a) Using more plastics
b) Promoting deforestation
c) Adopting sustainable practices
d) Ignoring waste management
Answer: c) Adopting sustainable practices

What type of substance is clay?
a) Biodegradable
b) Non-biodegradable
c) Renewable
d) Recyclable
Answer: b) Non-biodegradable

Which of the following is an eco-friendly practice?
a) Using disposable plastics
b) Composting kitchen waste
c) Throwing garbage in open areas
d) Using chemical pesticides
Answer: b) Composting kitchen waste

What happens to energy at the highest trophic level?
a) It increases
b) It is lost as heat
c) It is recycled
d) It remains unused
Answer: b) It is lost as heat

What causes acid rain?
a) Excess oxygen in the atmosphere
b) Emission of sulfur dioxide and nitrogen oxides
c) Reduction in greenhouse gases
d) Decomposition of organic waste
Answer: b) Emission of sulfur dioxide and nitrogen oxides

What is the impact of overuse of synthetic fertilizers?
a) Improves biodiversity
b) Causes soil pollution and water contamination
c) Increases natural decomposition
d) Promotes ecosystem balance
Answer: b) Causes soil pollution and water contamination