Question

sickle cell anemia is a genetic disease caused by a recessive allele. sickle cell anemia affects the hemoglobin in red blood cells, making them the shape of crescents instead of disks. the disease can cause pain and damage blood vessels. a genetic counselor meets with a man and a woman that both are carriers of sickle cell anemia. carriers have one copy of the sickle cell allele and one copy of the allele for making normal hemoglobin. what is the probability that the couple would have a child that was also a carrier for sickle cell anemia? 0% 25% 50% 75% 100% done

Explanation:

Step1: Define alleles

Let S be the normal allele and s be the sickle - cell allele. Both parents are carriers, so their genotypes are Ss.

Step2: Set up Punnett - square

The possible gametes from each parent are S and s. The Punnett - square has 4 possible combinations: SS, Ss, sS, ss.

Step3: Determine carrier genotypes

Carrier genotypes are Ss or sS. Out of 4 possible genotypes (SS, Ss, sS, ss), 2 are carriers (Ss and sS).

Step4: Calculate probability

The probability of having a carrier child is $\frac{2}{4}= 50\%$.

Answer:

50%