Habitats and Ecosystems — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. In the food chain sun → grass → rabbit → hawk, what is the rabbit?
A) producer
B) decomposer
C) consumer
D) predator only
A consumer is an animal that eats other organisms (plants or animals) to get energy.
2. Which of these is a producer in a forest food chain?
A) mushroom
B) oak tree
C) squirrel
D) fox
An oak tree is a producer because plants make their own food using sunlight through photosynthesis.
3. What would most likely happen if all the decomposers in a forest disappeared?
A) More plants would grow.
B) Dead leaves and animals would pile up.
C) Herbivores would have more food.
D) Rain would stop falling.
Without decomposers, dead plants and animals would not be broken down, so they would pile up and nutrients would not return to the soil.
4. Which habitat has very little rainfall and extreme temperatures?
A) forest
B) ocean
C) grassland
D) desert
The desert habitat is known for very little rainfall and extreme heat during the day.
Part B: Fill in the Blank
Write the correct answer on each line.
1. A hawk that eats a snake that ate a mouse is called a tertiary consumer.
A tertiary consumer is at the top of the food chain and eats secondary consumers.
2. Grass is a producer because it makes food from sunlight.
Every food chain starts with a producer, which makes its own food using energy from the sun.
3. Worms and fungi are examples of decomposers.
Mushrooms and bacteria are decomposers that break down dead organisms and recycle nutrients back into the soil.
4. A food chain always starts with a producer.
Grass is the producer in this food chain because it uses sunlight to make its own food.
5. Animals that are hunted by other animals are called prey.
Prey is an animal that is hunted and eaten by a predator.