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
The rabbit eats the grass, so it gets its energy from another living thing instead of making its own food. Any organism that eats other organisms for energy is a consumer.
2. Which of these is a producer in a forest food chain?
A) mushroom
B) oak tree
C) squirrel
D) fox
Producers make their own food using sunlight through photosynthesis. The oak tree does this with its leaves, while the squirrel, fox, and mushroom all have to eat other living things.
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.
Decomposers break down dead plants and animals and return nutrients to the soil. Without them, dead leaves and animals would stop being recycled and would simply build up across the forest floor.
4. Which habitat has very little rainfall and extreme temperatures?
A) forest
B) ocean
C) grassland
D) desert
Deserts are known for getting very little rain and for swinging between scorching days and chilly nights. That mix of dryness and extreme temperatures is what sets a desert apart from the other habitats listed.
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.
Counting up the chain helps: the mouse is the primary consumer, the snake that eats it is the secondary consumer, and the hawk that eats the snake is the third, or tertiary, consumer.
2. Grass is a producer because it makes food from sunlight.
Plants like grass capture energy from the sun and turn it into food through photosynthesis, which is exactly what makes something a producer.
3. Worms and fungi are examples of decomposers.
Worms and fungi feed on dead plants and animals, breaking them down into nutrients that go back into the soil. That recycling job is the work of decomposers.
4. A food chain always starts with a producer.
Energy in every food chain has to come from somewhere, and it always begins with a producer that captures sunlight and turns it into food the other organisms can eat.
5. Animals that are hunted by other animals are called prey.
When one animal hunts another, the animal being hunted is called prey. Prey is the food source that keeps predators alive.