Skip to content

Course home

7.4 Trophic levels in an ecosystem

7.4 Trophic levels in an ecosystem

EasyMediumHard
12345678910111213141516171819
Question 13

In a marine conservation zone, a giant kelp forest (Macrocystis pyrifera) produces biomass at a rate of 2800 g m−2 year−12800 \text{ g m}^{-2} \text{ year}^{-1}2800 g m−2 year−1.

a.

Assuming an average biomass transfer efficiency of 7.5%7.5\%7.5% from producers to primary consumers, calculate the rate of biomass from this kelp forest that is successfully transferred into the biomass of primary consumers (such as sea urchins). Give your answer in g m−2 year−1\text{g m}^{-2} \text{ year}^{-1}g m−2 year−1.

[2]
b.

Explain two biological reasons why a significant proportion of the biomass produced by the giant kelp is not transferred into the biomass of these primary consumers.

[2]
Markscheme

7.4 Trophic levels in an ecosystem Questions

  1. GCSE
  2. /Biology
  3. /7.4 Trophic levels in an ecosystem

61 exam-style questions on AQA GCSE Biology 7.4 Trophic levels in an ecosystem, covering 7.4.1 Trophic levels, 7.4.2 Pyramids of biomass, and 7.4.3 Transfer of biomass. Each one has a worked solution and a mark scheme showing where the marks go.

Question bank