In a food web, each depends on the trophic level below it for energy

a) consumer
b) decomposer
c) detritivore
d) producer

The correct answer would be A) consumers.

Consumers are the organisms which depend on other organisms for their energy needs.

In a food chain, the consumer consumes other organisms present on lower trophic level.

For example, cow, deer, et cetera (herbivore) are the primary consumers which consume autotrophs or green plants which are present on lowest trophic level.

Similarly, lion, tiger, et cetera are the highest consumers which feed on organisms present on lower trophic levels such as cow, deer, giraffe et cetera.

1. dermis

2. chemical

3. urine

4. viruses

5. antibodies

b - the respond is innate and varies over time.

good luck!