Scientists investigated the survival of tadpoles of one frog species.
Two tanks contained equal volumes of water. The temperature and dissolved oxygen concentration were kept the same in both tanks. The same mass of food was added to each tank every day.
The table shows the results after six weeks.
| Tank | Number of tadpoles at the start | Number of tadpoles surviving after six weeks |
|---|---|---|
| A | 20 | 16 |
| B | 80 | 28 |
Calculate how many times as large the percentage survival was in tank A as in tank B.
Give your answer to 2 significant figures.
Suggest why a tadpole in tank B was less likely to survive than a tadpole in tank A.
82 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.