Habitats and Ecosystems — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. Bees help flowers by spreading pollen from plant to plant.
Pollen sticks to a bee's fuzzy body as it sips nectar, then rubs off on the next flower it visits, helping plants make seeds and new fruit.
2. When animals breathe out, they release carbon dioxide that plants need.
Animals breathe in oxygen and breathe out carbon dioxide as a waste gas, but plants soak up that same carbon dioxide to perform photosynthesis.
3. A secondary consumer eats primary consumers, like a frog eating insects.
"Secondary" means second, so a secondary consumer is the second eater in the chain — a meat-eater that hunts the herbivores who munched the plants.
4. The nonliving parts of an ecosystem are called abiotic factors.
The prefix "a-" means without and "biotic" means life, so abiotic factors are the nonliving things like sunlight, water, rocks, and air.
5. Trees provide shelter and food for many forest animals.
Trees offer hollow trunks for owls, leafy branches for squirrel nests, and bark for insects to hide under, giving forest animals safe places to live.
6. Without sunlight, plants cannot make food through photosynthesis.
Photosynthesis literally means "putting together with light," so without sunlight a plant cannot turn carbon dioxide and water into the sugar it uses for food.
7. An ecosystem where trees lose their leaves each fall is a deciduous forest.
Deciduous trees like oak and maple drop their leaves every autumn to save water during the cold winter when the ground is often frozen.
8. Earthworms improve soil by creating air spaces as they dig tunnels.
Worm tunnels open up tiny passageways in packed dirt, letting oxygen and water reach plant roots so the soil becomes loose and healthy.
9. The living parts of an ecosystem are called biotic factors.
The root "bio" means life, so biotic factors are everything that is or once was alive — animals, plants, fungi, and bacteria.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each habitat feature to its correct biome.
frozen ground year-round
→ tundra
grassland
very heavy daily rainfall
→ rainforest
desert
tall grasses and few trees
→ grassland
tundra
sand dunes and cacti
→ desert
rainforest
Each clue points to a unique biome: permanent frost only happens in the tundra, daily downpours soak the rainforest, open seas of grass mark the grassland, and dunes with cacti belong to the desert.