Skip to content

Course home

7.1 Adaptations, interdependence and competition

7.1 Adaptations, interdependence and competition

EasyMediumHard
123456789101112131415161718192021
Question 17

Biologists investigated the population density of the freshwater crustacean Gammarus pulex in an artificial research flume.

They used the following sampling method:

  1. Collect 1 dm3 of water from a randomly selected section of the flume.
  2. Filter the water sample through a fine mesh and count the number of Gammarus pulex retrieved.
  3. Repeat the process to obtain five samples in total.

Table of Results

Sample numberNumber of Gammarus pulex in 1 dm3 of water
121
234
37
418
545
a.

Calculate the mean number of Gammarus pulex in 1 m3 of the flume water. (Note: 1 m3=1000 dm31\text{ m}^3 = 1000\text{ dm}^31 m3=1000 dm3)

[2]
b.

The flume is a rectangular channel with the following dimensions:

  • length=6.4 m\text{length} = 6.4\text{ m}length=6.4 m
  • width=1.5 m\text{width} = 1.5\text{ m}width=1.5 m
  • water depth=0.25 m\text{water depth} = 0.25\text{ m}water depth=0.25 m

Calculate the estimated total population of Gammarus pulex in the flume. Give your answer in standard form.

[3]
Markscheme

7.1 Adaptations, interdependence and competition Questions

  1. GCSE
  2. /Biology
  3. /7.1 Adaptations, interdependence and competition

63 exam-style questions on AQA GCSE Biology 7.1 Adaptations, interdependence and competition, covering 7.1.1 Communities, 7.1.2 Abiotic factors, 7.1.3 Biotic factors, and 7.1.4 Adaptations. Each one has a worked solution and a mark scheme showing where the marks go.

Question bank