A certain chemical used as a mouse poison targets and destroys red blood cells in the blood.
Describe the function of red blood cells in the blood.
Some mice are resistant to this chemical. Scientists found that the resistance is due to a dominant allele, DDD.
Two resistant mice containing the heterozygous genotype DdDdDd mate.
Complete the genetic diagram to find the expected ratio of resistant mice to non-resistant mice among their offspring.
| ... | ... | |
|---|---|---|
| D | ... | ... |
| d | ... | ... |
Ratio of resistant to non-resistant mice =
After several years of using this chemical, the percentage of resistant mice in the population increased.
Use Darwin’s theory of natural selection to explain this observation.
Scientists are now trialling a new chemical that blocks the action of ribosomes in animal cells.
Explain why this chemical would kill the mice.
97 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.