A species of microscopic organism can reproduce sexually or asexually.
Researchers placed 30 organisms into each of two identical containers. Both containers had the same amount of food and were kept at pH 7 for six days. Population A reproduced asexually and population B reproduced sexually.
The researchers then changed both containers to pH 4 for 24 hours and counted the organisms that survived.
| Population | Method of reproduction | Number after six days at pH 7 | Number surviving after 24 hours at pH 4 |
|---|---|---|---|
| A | asexual | 960 | 48 |
| B | sexual | 360 | 144 |
Explain why the method of reproduction used by population A was suitable during the first six days. Use information from the table.
Explain which method of reproduction gave an individual organism the greater chance of surviving at pH 4. Use the data in the table.
The survivors in population B reproduce sexually at pH 4 for several generations. Give one prediction for how the proportion surviving at pH 4 would change over these generations.
92 exam-style questions on Edexcel GCSE Biology 3.1 Reproduction and meiosis, covering 3.1.1 Advantages and disadvantages of reproduction and 3.1.2 Role of meiotic cell division. Each one has a worked solution and a mark scheme showing where the marks go.