Q.1 What is an ecosystem?
A group of mountains
A community of organisms and their environment
A single animal species
A weather system
Explanation - An ecosystem is the interaction between living organisms (plants, animals, microorganisms) and their physical environment (air, water, soil).
Correct answer is: A community of organisms and their environment
Q.2 Which of the following is a biotic component of an ecosystem?
Soil
Sunlight
Plants
Water
Explanation - Biotic components are the living parts of an ecosystem such as plants, animals, and microbes.
Correct answer is: Plants
Q.3 Which of these is an example of a producer in an ecosystem?
Lion
Grass
Fungi
Vulture
Explanation - Producers, like green plants, make their own food using photosynthesis and form the base of the food chain.
Correct answer is: Grass
Q.4 Decomposers in an ecosystem primarily help in:
Recycling nutrients
Producing oxygen
Creating energy
Storing water
Explanation - Decomposers break down dead organisms and waste, returning nutrients to the soil.
Correct answer is: Recycling nutrients
Q.5 Which of the following ecosystems has the highest biodiversity?
Tundra
Desert
Tropical rainforest
Grassland
Explanation - Tropical rainforests have warm temperatures, abundant rainfall, and support a wide variety of species.
Correct answer is: Tropical rainforest
Q.6 What role do carnivores play in an ecosystem?
They produce food
They recycle nutrients
They control herbivore populations
They fix nitrogen
Explanation - Carnivores regulate herbivore populations, maintaining balance in the food chain.
Correct answer is: They control herbivore populations
Q.7 Which cycle moves water through ecosystems?
Nitrogen cycle
Carbon cycle
Water cycle
Oxygen cycle
Explanation - The water cycle circulates water through evaporation, condensation, precipitation, and infiltration.
Correct answer is: Water cycle
Q.8 What term is used for animals that eat both plants and animals?
Carnivores
Herbivores
Omnivores
Decomposers
Explanation - Omnivores feed on both plant and animal matter, gaining energy from multiple sources.
Correct answer is: Omnivores
Q.9 Which of these is an abiotic factor in an ecosystem?
Fish
Grass
Soil
Deer
Explanation - Abiotic factors are the non-living elements of an ecosystem such as soil, water, and temperature.
Correct answer is: Soil
Q.10 Which gas do plants release during photosynthesis?
Carbon dioxide
Oxygen
Nitrogen
Methane
Explanation - Plants release oxygen as a byproduct of photosynthesis, essential for animal life.
Correct answer is: Oxygen
Q.11 Energy flow in an ecosystem is:
Cyclic
One-way
Irregular
Unnecessary
Explanation - Energy flows in one direction from producers to consumers to decomposers, unlike nutrients which cycle.
Correct answer is: One-way
Q.12 Which of these is an example of a primary consumer?
Deer
Tiger
Eagle
Snake
Explanation - Primary consumers feed directly on producers (plants). Deer eat grass and other vegetation.
Correct answer is: Deer
Q.13 Which ecosystem is characterized by very low rainfall and extreme temperatures?
Rainforest
Grassland
Desert
Tundra
Explanation - Deserts receive very little rainfall and have harsh temperature conditions.
Correct answer is: Desert
Q.14 Mangroves are found in which type of ecosystem?
Freshwater rivers
Coastal wetlands
Deserts
Grasslands
Explanation - Mangroves grow in saline coastal wetlands and are adapted to brackish water.
Correct answer is: Coastal wetlands
Q.15 The top predators in a food chain are called:
Producers
Primary consumers
Apex predators
Decomposers
Explanation - Apex predators occupy the highest trophic level and have no natural predators.
Correct answer is: Apex predators
Q.16 Which of these ecosystems is known for permafrost?
Savanna
Tundra
Rainforest
Coral reef
Explanation - The tundra has permanently frozen soil called permafrost, limiting plant growth.
Correct answer is: Tundra
Q.17 What is the main source of energy for most ecosystems?
Wind
Sunlight
Soil
Water
Explanation - Sunlight drives photosynthesis, the foundation of energy for most ecosystems.
Correct answer is: Sunlight
Q.18 Which organisms fix nitrogen in ecosystems?
Fungi
Bacteria
Herbivores
Carnivores
Explanation - Nitrogen-fixing bacteria convert atmospheric nitrogen into forms usable by plants.
Correct answer is: Bacteria
Q.19 What do food webs represent?
Only herbivores eating plants
Single energy pathways
Interconnected food chains
Only decomposers
Explanation - Food webs show the complex feeding relationships between organisms in an ecosystem.
Correct answer is: Interconnected food chains
Q.20 Which of the following is a freshwater ecosystem?
Ocean
Pond
Mangrove
Coral reef
Explanation - Ponds, lakes, and rivers are examples of freshwater ecosystems.
Correct answer is: Pond
Q.21 Which term refers to the variety of life in an ecosystem?
Abiotic factors
Carrying capacity
Biodiversity
Niche
Explanation - Biodiversity is the variety of species, genes, and ecosystems in a given area.
Correct answer is: Biodiversity
Q.22 Which biome covers the largest area on Earth?
Grasslands
Oceans
Rainforests
Tundra
Explanation - Oceans cover about 71% of Earth’s surface, making them the largest biome.
Correct answer is: Oceans
Q.23 What is ecological succession?
Seasonal change in weather
Gradual change in ecosystems over time
Animal migration
Pollution control
Explanation - Ecological succession is the natural process of change in ecosystems as species composition shifts.
Correct answer is: Gradual change in ecosystems over time
Q.24 Coral reefs are often called:
Deserts of the sea
Rainforests of the sea
Savannas of the sea
Tundras of the sea
Explanation - Coral reefs are called 'rainforests of the sea' because of their rich biodiversity.
Correct answer is: Rainforests of the sea
Q.25 Which of the following can cause disruption in ecosystems?
Deforestation
Recycling
Conservation
Tree planting
Explanation - Deforestation removes trees, disrupts habitats, and alters ecosystem balance.
Correct answer is: Deforestation