Achromatopsia is an inherited eye condition.
It is caused by a gene mutation that produces a recessive allele.
The condition causes cone cells in the retina to become damaged or non-functional.
Explain the meaning of these genetic terms:
Two parents who are heterozygous for achromatopsia are expecting a child. Draw a genetic diagram to calculate the probability that the child will have the condition. Use A A\,A for the normal allele and a a\,a for the allele for achromatopsia.
Individuals with complete achromatopsia have normal vision in dim light but cannot perceive colours. Explain why.
Explain why stem cells could be used as a treatment for this condition.
Why is it an advantage to use stem cells harvested from the patient rather than from another person?
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.