Question

The image shows the cross between two parents who are carriers for sickle cell anemia, a recessive genetic disorder that affects the red blood cells in humans. Both parents are considered to be Response area. The probability that these parents will have an offspring affected with sickle cell anemia is Response area percent. The probability that their offspring would also be a carrier like them is Response area percent.

Answer 1

In order to determine the probabilities for the offspring of parents who are carriers for sickle cell anemia, we need to first understand the genetic inheritance pattern.

1. Genotype of the Parents: Both parents are carriers, meaning their genotypes are HbA/HbS (where HbA is the normal allele and HbS is the allele for sickle cell anemia).

2. Possible Genotypes for Offspring: When both parents are carriers, we can set up a Punnett square to visualize the possible combinations of alleles for their children:

   • Parent 1 (Carrier): HbA / HbS
   • Parent 2 (Carrier): HbA / HbS

   The possible combinations from this cross would be:

   • HbA/HbA (normal)
   • HbA/HbS (carrier)
   • HbA/HbS (carrier)
   • HbS/HbS (affected)

3. Probability of Affected Offspring:

   • There is 1 out of 4 (25%) chance for an offspring to have sickle cell anemia (HbS/HbS).

4. Probability of Carrier Offspring:

   • There are 2 out of 4 (50%) chances for an offspring to be a carrier (HbA/HbS).

Putting this information together:

• The probability that these parents will have an offspring affected with sickle cell anemia is 25 percent.
• The probability that their offspring would also be a carrier like them is 50 percent.