A marine biologist investigated the impact of microplastic concentration on the feeding activity of the marine zooplankton Daphnia magna. She obtained a sample of 50 experimental jars, each containing a group of zooplankton, from a marine research laboratory.
Environment A: Zooplankton were kept in water with a high concentration of polyethylene microparticles (high-microplastic environment).
Environment B: Zooplankton were kept in standard filtered seawater (low-microplastic environment).
After 24 hours, the biologist recorded the filtration rate (in mL/hour per individual) as a measure of feeding activity, and the number of inactive individuals per jar.
The median filtration rate and the median number of inactive individuals for each environment were calculated. The results are shown in Table 1.
Table 1 The median filtration rate and median number of inactive individuals in the two environments
| High-microplastic environment | Low-microplastic environment | |
|---|---|---|
| Median filtration rate (mL/hour) | 1.8 | 6.4 |
| Median number of inactive individuals | 15 | 3 |
What can the marine biologist conclude from the results in Table 1?
Justify your answer.
235 exam-style questions on AQA A Level Psychology Data handling and analysis. Each one has a worked solution and a mark scheme showing where the marks go.