Answer:
Explanation:
The disease sickle cell anemia is caused by homozygosity for a mutation:
Albinism is a recessive trait:
The genes S/s and A/a are linked and separated by 1 map unit.
Remember that 1 mu means that 1% of the gametes produced by an individual will be recombinant.
Son: Sa/sA
The gametes he can produce are:
Since the frequency of recombination is 1% (or 0.01), each recombinant gamete has a frequency of 0.005 (since there are two possible recombinant gametes).
The parental gametes will appear with a frequency of 0.99, each of them with a frequenct of 0.495.
Daughter: SA/sa
The gametes she can produce are:
In order for them to have an albino child with anemia (sa/sa), the gamete sa from each parent had to be produced and fused into the zygote. Since the production of gametes by each parent is an independent event, the probability of having sa/sa offspring can be calculated as:
Prob. sa gamete son × Prob. sa gamete daughter = 0.005 × 0.495 = 0.0025
The probability that a child of theirs will be an albino with sickle-cell anemia is 0.25%
