Question

question #10
jackson’s mother and father both have normal blood cells, a dominant trait, while jackson has sickle cell anemia, a recessive trait. which genotype for sickle cell anemia represents each of jackson’s parents’ traits?
a aa
b aa
c normal blood cells
d sickle cell anemia

question #11
examine the punnett square.
punnett square with t, t on top and t, t on the side
what percentage of the offspring should be purebred recessive?
a 25%
b 50%
c 75%
d 100%

Explanation:

Question #10

Sickle cell anemia is recessive (\(aa\)), so Jackson's genotype is \(aa\). His parents have normal blood (dominant), meaning they must carry the recessive allele to pass it to Jackson. A dominant trait with a recessive allele carrier has genotype \(Aa\) (heterozygous). \(AA\) would not pass the recessive allele, "normal blood cells" is a phenotype, and "sickle cell anemia" is Jackson's phenotype/genotype, not his parents'. So the parents' genotype is \(Aa\) (Option A).

Step1: Complete the Punnett square

The Punnett square has parents with genotypes \(Tt\) (row: \(T, t\); column: \(T, t\)). Filling it:

• Top - left: \(T \times T = TT\)
• Top - right: \(T \times t = Tt\)
• Bottom - left: \(t \times T = Tt\)
• Bottom - right: \(t \times t = tt\)

Step2: Identify purebred recessive

Purebred recessive is \(tt\) (homozygous recessive). Out of 4 offspring, 1 is \(tt\).

Step3: Calculate percentage

Percentage = \(\frac{1}{4} \times 100\% = 25\%\)

Answer:

A. Aa

Question #11