Câu 1: What is an ecosystem?

A. A type of machine

B. A community of living organisms interacting with their environment

C. A factory system

D. A school building

Câu 2: Which of these is a freshwater ecosystem?

A. Ocean

B. Lake

C. Desert

D. Coral reef

Câu 3: What is the largest ecosystem on Earth?

A. Forest

B. Desert

C. Ocean

D. Lake

Câu 4: Which is a non-living part of an ecosystem?

A. Tree

B. Water

C. Fish

D. Bird

Câu 5: Which of the following is a producer in an ecosystem?

A. Lion

B. Grass

C. Tiger

D. Eagle

Câu 6: What do consumers eat in an ecosystem?

A. Stones

B. Other organisms

C. Air

D. Soil

Câu 7: Which of these is a decomposer?

A. Mushroom

B. Rabbit

C. Dog

D. Fish

Câu 8: Which ecosystem is characterized by high rainfall?

A. Desert

B. Rainforest

C. Grassland

D. Tundra

Câu 9: What is biodiversity?

A. Only one type of species

B. The variety of life in an ecosystem

C. Plastic in the ocean

D. Number of cars in a city

Câu 10: Which of these is a marine ecosystem?

A. River

B. Lake

C. Coral reef

D. Forest

Câu 11: Which gas is most important for photosynthesis?

A. Oxygen

B. Carbon dioxide

C. Nitrogen

D. Hydrogen

Câu 12: What role do plants play in an ecosystem?

A. Producer

B. Consumer

C. Decomposer

D. Predator

Câu 13: Which of these animals is a herbivore?

A. Lion

B. Elephant

C. Tiger

D. Eagle

Câu 14: What is a food chain?

A. A metal chain

B. A series of organisms where each eats the one before it

C. A shopping list

D. A mountain range

Câu 15: What is the top predator in a food chain called?

A. Decomposer

B. Apex predator

C. Producer

D. Scavenger

Câu 16: Which ecosystem is the coldest?

A. Desert

B. Rainforest

C. Tundra

D. Grassland

Câu 17: Which human activity harms ecosystems the most?

A. Recycling

B. Deforestation

C. Planting trees

D. Saving water

Câu 18: What is the main source of energy for ecosystems?

A. Wind

B. Water

C. The Sun

D. The Moon

Câu 19: Which of the following is a biotic factor in an ecosystem?

A. Soil

B. Temperature

C. Fish

D. Water

Câu 20: Which ecosystem has the highest biodiversity?

A. Desert

B. Ocean

C. Tropical rainforest

D. Arctic

Câu 21: What is a scavenger in an ecosystem?

A. A producer

B. An animal that eats dead organisms

C. A plant

D. A virus

Câu 22: Which of these is a grassland ecosystem?

A. Sahara Desert

B. Amazon Rainforest

C. African Savanna

D. Arctic Tundra

Câu 23: What is the main characteristic of a desert ecosystem?

A. Heavy rainfall

B. Very little rainfall

C. Thick forests

D. Many rivers

Câu 24: What do decomposers do in an ecosystem?

A. Produce energy

B. Break down dead organisms

C. Hunt other animals

D. Store water

Câu 25: What is a population in an ecosystem?

A. All the non-living things

B. A group of the same species living in one area

C. A food web

D. A type of climate

Câu 26: Which of these is an abiotic factor?

A. Bird

B. Tree

C. Water temperature

D. Fish

Câu 27: What is the role of algae in aquatic ecosystems?

A. Predator

B. Decomposer

C. Producer

D. Scavenger

Câu 28: Which of these is an example of mutualism?

A. Lion eating a zebra

B. Bees pollinating flowers

C. Shark eating fish

D. Eagle hunting a rabbit

Câu 29: Which ecosystem type covers most of the Earth’s surface?

A. Desert

B. Ocean

C. Forest

D. Grassland

Câu 30: Why are coral reefs important to ecosystems?

A. They produce oxygen

B. They provide habitat for marine species

C. They increase global warming

D. They create deserts

Câu 31: Which of these is an invasive species?

A. A native tree

B. A species introduced that harms local ecosystems

C. A decomposer

D. A herbivore

Câu 32: What is a food web?

A. A single food chain

B. Interconnected food chains in an ecosystem

C. A fishing net

D. A water filter

Câu 33: What is ecosystem balance?

A. Overpopulation of one species

B. Stable interaction between all living and non-living parts

C. Building houses in the forest

D. Removing all predators

Câu 34: Which of the following increases biodiversity?

A. Deforestation

B. Protecting habitats

C. Pollution

D. Overfishing

Câu 35: Which organism is an example of a predator?

A. Grasshopper

B. Cow

C. Lion

D. Rabbit

Câu 36: What is habitat destruction?

A. Protecting animal homes

B. Damaging or removing natural living spaces

C. Planting more trees

D. Building nature reserves

Câu 37: What is the role of the Sun in ecosystems?

A. No role

B. Main source of energy

C. Producing oxygen

D. Creating rainfall

Câu 38: What is a keystone species?

A. A species that has a big impact on its ecosystem

B. The largest animal

C. The oldest plant

D. A decomposer

Câu 39: Which of the following is NOT an ecosystem?

A. Forest

B. Desert

C. Aquarium

D. Shopping mall

Câu 40: What is the role of oxygen in ecosystems?

A. It is not needed

B. It helps animals and plants breathe

C. It destroys plants

D. It increases soil erosion

Câu 41: Which ecosystem is called the “lungs of the Earth”?

A. Desert

B. Rainforest

C. Tundra

D. Grassland

Câu 42: What is overgrazing?

A. Planting more grass

B. Animals eating too many plants in one area

C. Saving plants from animals

D. Protecting grasslands

Câu 43: Which animal is important for seed dispersal?

A. Snake

B. Elephant

C. Butterfly

D. Fish

Câu 44: What is the main source of food in most ecosystems?

A. Predators

B. Producers like plants

C. Decomposers

D. Carnivores

Câu 45: What is soil erosion?

A. Making soil stronger

B. Wearing away of soil by wind or water

C. Growing more soil

D. Building houses on soil

Câu 46: What happens when an ecosystem loses its top predator?

A. No change

B. Population of prey increases too much

C. Plants grow faster

D. Soil disappears

Câu 47: What is a drought?

A. Too much rain

B. A long period without rain

C. Heavy snowfall

D. Increased river flow

Câu 48: Which of the following is a carnivore?

A. Cow

B. Tiger

C. Sheep

D. Deer

Câu 49: Which of these is an endangered species?

A. House cat

B. Panda

C. Sparrow

D. Cockroach

Câu 50: What is a biome?

A. A large area with similar climate and ecosystems

B. A building

C. A small pond

D. A group of people

Câu 51: Which biome has the most species diversity?

A. Tundra

B. Rainforest

C. Desert

D. Grassland

Câu 52: What is an estuary?

A. Where a river meets the sea

B. A mountain peak

C. A desert area

D. A dry lake

Câu 53: Which of the following is a renewable resource?

A. Coal

B. Oil

C. Sunlight

D. Gas

Câu 54: What is a limiting factor in an ecosystem?

A. Something that increases population endlessly

B. Something that controls population size like food or water

C. A human invention

D. A type of fish

Câu 55: Which gas do animals release during respiration?

A. Oxygen

B. Carbon dioxide

C. Nitrogen

D. Helium

Câu 56: What is the frozen ecosystem called?

A. Rainforest

B. Tundra

C. Desert

D. Grassland

Câu 57: What does photosynthesis produce?

A. Carbon dioxide

B. Oxygen and sugar

C. Water

D. Oil

Câu 58: What is a primary consumer?

A. An animal that eats producers (plants)

B. A plant

C. A decomposer

D. A carnivore that eats other consumers

Câu 59: Which of the following is a detritivore?

A. Vulture

B. Earthworm

C. Deer

D. Rabbit

Câu 60: What is a habitat?

A. The natural home of an organism

B. A human house

C. A shopping mall

D. A bridge