Every fall, a thick layer of leaves covers a forest floor. By the next summer the leaves are gone. Where has most of the matter from those leaves gone?

On a fallen log in a forest, a student finds a mushroom, a fern, a squirrel, and a caterpillar. Which one is a decomposer?

A family puts banana peels and dead leaves into a compost bin. Months later the bin holds dark, crumbly material instead. What best explains the change?

A tomato seedling grows into a large plant with heavy stems and many leaves. Most of the material that makes up all that new growth came from which source?

A rabbit spends the summer eating grass and grows much larger. Where did the matter that makes up the rabbit's new body parts come from?

In a food web model, arrows show matter moving from one place to the next. A deer dies on the forest floor. Where should the next arrow for its matter point?

Decomposers return nutrients from dead plants and animals to the soil, where growing plants can take them in again.

A gardener mixes finished compost into a flower bed, and the flowers grow better than they did last year. What does the compost supply?

In an ecosystem, matter cycles among plants, animals, decomposers, and the environment. What happens to energy in that same ecosystem?

A sealed glass terrarium holding plants, soil, and pill bugs stays healthy on a sunny windowsill for months. Nothing is added. What keeps material available inside it?

Imagine every decomposer vanished from a forest. What would most likely happen over the next several years?

A grasshopper eats grass in a meadow. Is the grasshopper acting as a producer, a consumer, or a decomposer?

A class weighs a compost pile. In week 1 it has a mass of 12 kilograms. In week 8 the same pile has a mass of 7 kilograms. What happened to the missing 5 kilograms?

Dead leaves blow into a pond in the fall and slowly break apart over the winter. What happens to the nutrients that were in those leaves?

Earthworms in a garden help break dead leaves into smaller pieces that mix into the soil.

Two piles of dead leaves sit in a forest. One pile stays damp and warm. The other stays dry and cold. Which pile will most likely break down faster?

A student claims that matter cycles through a forest instead of being used up. Which observation best supports that claim?

A student draws a model of a meadow food web showing plants, mice, and hawks. Which group is missing if the model needs to show matter returning to the soil?

Mushrooms are one kind of decomposer in soil. Which other living things break down dead material there?

After harvest, a farmer plows the cut cornstalks back into the field instead of hauling them away. How does this help next year's crop?