Researchers studied a species of pond organism that can reproduce asexually or sexually. Over 12 weeks, they recorded the following data for each adult:
| Method of reproduction | Offspring per reproductive event | Reproductive events per adult | Offspring surviving to reproductive age (%) |
|---|---|---|---|
| Asexual | 2 | 10 | 60 |
| Sexual | 8 | 3 | 75 |
A new disease entered the pond. The researchers recorded the following results:
| Group | Main method of reproduction | Number before the disease entered the pond | Number surviving the disease |
|---|---|---|---|
| A | Asexual | 180 | 18 |
| B | Sexual | 160 | 96 |
Offspring in a sample have the same genetic information as their parent. Give the reproductive method most likely to have produced them.
Calculate the number of offspring surviving to reproductive age per adult for each method over the 12 weeks. Explain which method resulted in the greater number.
Explain why the disease-survival results suggest that sexual reproduction may help a population when a new disease enters its environment.
One organism is carried to a different pond, where it is the only member of its species. Suggest one advantage of reproducing asexually in these circumstances.
186 exam-style questions on OCR GCSE Biology 5.1 Inheritance, covering 5.1.1 The genome, 5.1.2 Environment and phenotype, 5.1.3 Variants and mutations, 5.1.4 How genetic variants influence phenotype, 5.1.5 Asexual and sexual reproduction, 5.1.6 Haploid and diploid, 5.1.7 Meiotic cell division, 5.1.8 Single gene inheritance, 5.1.9 Predicting single gene crosses, 5.1.10 Sex determination, 5.1.11 Multiple gene inheritance, and 5.1.12 Development of our understanding of genetics. Each one has a worked solution and a mark scheme showing where the marks go.