Question

1. sickle cell anemia is condition that shows codominance. the genotype for normal blood cells is nn. sickle cell trait is the heterozygous condition (ns) and contains both normal and sickle shaped blood cells. sickle cell disease (ss) is when all of the blood cells are sickle - shaped and has lifelong medical implications. a man with sickle cell trait has a child with a woman with sickle cell trait.

k. complete the punnett square.
l. what is the probability of having a child with sickle cell trait?
m. what is the probability of having a normal offspring?
n. what is the probability of having a child with sickle cell disease?

Explanation:

Part k: Complete the Punnett Square

Step 1: Identify Parental Genotypes

Both parents have sickle cell trait, so their genotype is \( NS \). Each parent can contribute either \( N \) or \( S \) allele.

Step 2: Set Up Punnett Square

The rows and columns of the Punnett square are labeled with the alleles from each parent. So the top row (father's alleles) and left column (mother's alleles) will have \( N \) and \( S \).

Step 3: Fill in the Punnett Square

• Top - left cell: \( N \) (father) × \( N \) (mother) = \( NN \)
• Top - right cell: \( N \) (father) × \( S \) (mother) = \( NS \)
• Bottom - left cell: \( S \) (father) × \( N \) (mother) = \( NS \)
• Bottom - right cell: \( S \) (father) × \( S \) (mother) = \( SS \)

So the Punnett square is:

	\( N \)	\( S \)
\( S \)	\( NS \)	\( SS \)

Part l: Probability of Sickle Cell Trait (\( NS \))

Step 1: Count Favorable Outcomes

From the Punnett square, the number of cells with genotype \( NS \) is 2.

Step 2: Total Outcomes

The total number of cells in the Punnett square is 4.

Step 3: Calculate Probability

Probability \( = \frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}}=\frac{2}{4}=\frac{1}{2} \) or 50%.

Step 1: Count Favorable Outcomes

From the Punnett square, the number of cells with genotype \( NN \) is 1.

Step 2: Total Outcomes

The total number of cells in the Punnett square is 4.

Step 3: Calculate Probability

Probability \( = \frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}}=\frac{1}{4} \) or 25%.

Answer:

\(\frac{1}{2}\) (or 50%)

Part m: Probability of Normal Offspring (\( NN \))