Question

energy & matter in ecosystems
modified from image courtesy of usda
which of the following statements correctly describes how matter cycles among organisms within this ecosystem?
a. only decomposers cycle matter within this ecosystem.
b. most of the matter in this ecosystem comes from nematodes.
c. arthropods obtain matter directly from nematodes.
d. fungi obtain matter directly from arthropods.

Explanation:

1. Analyze Option A: Producers (plants) and consumers (like arthropods, birds, animals) also cycle matter (e.g., plants make organic matter, consumers eat and pass it on), so "only decomposers" is wrong.
2. Analyze Option B: Most matter in ecosystems comes from producers (plants) via photosynthesis, not nematodes (a consumer/decomposer group), so B is wrong.
3. Analyze Option C: The diagram shows an arrow from nematodes to arthropods, meaning arthropods (predators) get matter directly from nematodes (prey) – this matches the food web flow.
4. Analyze Option D: The diagram has arrows from plants/organic matter to fungi, not from arthropods to fungi. So fungi don’t get matter directly from arthropods – D is wrong.

Answer:

C. Arthropods obtain matter directly from nematodes.