Question

A woman has a father with sickle-cell anemia, which is an autosomal recessive trait. She does not have symptoms of sickle-cell anemia. What is her genotype? (0.5 marks)

b) She is about to start a family, and she knows that her partner’s mother has sickle-cell anemia, but he does not have the disease himself. What is the probability of them having a child with sickle-cell anemia? Demonstrate this using a Punnett square. (2.5 marks)

c) If they have three children, what is the probability that they will have two children with sicklecell anemia? Use the binomial expansion equation. Be sure to show your work and define the terms (n, p, q, s, and t) (2.5 marks)

d) The binomial expansion gives the following: p3 + 3p2 q + 3pq2 + q3 , with 3p2 q representing the probability of two children with sickle-cell anemia. Explain why it is multiplied by 3. (1 mark)

Answer 1

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