Question

In a food pyramid, there is typically less biomass at the top (i.e., there are very few individual tertiary consumers, whereas there are numerous individual producers). In three to five sentences, explain this phenomenon, citing evidence relating to energy flow and how plants support ecosystems.(4 points)

Short Answer Rubric (4 points)
Points Awarded Criteria
4
The answer is very clear.

The answer is fully supported by details.

There may be a few errors in grammar, usage, or mechanics. Errors do not interfere with meaning.

3
The answer is mostly clear.

The answer is supported by mostly relevant details.

There are a few errors in grammar, usage, or mechanics. Errors do not interfere with meaning.

2
The answer is somewhat clear.

Details are weak or not related.

There are some errors in grammar, usage, and mechanics. Errors interfere with meaning.

1
The answer is not clear.

There are few or no supporting details.

There are many errors in grammar, usage, and mechanics. Errors interfere with meaning.

0 The question is not answered.

Answer 1

In a food pyramid, there is less biomass at the top because energy is lost as it moves up the trophic levels. As plants (producers) convert sunlight into energy through photosynthesis, they support ecosystems by providing nutrients and energy for other organisms. When primary consumers (herbivores) consume plants, only about 10% of the energy consumed is transferred to them, with the rest being lost as heat or used for metabolic processes. This energy loss continues as it moves up the food chain, resulting in lower biomass at higher trophic levels. Therefore, there are fewer individual tertiary consumers as there is not enough energy to support a large population at the top of the food pyramid.