look at this cross: $x^b x^b$ x $x^b y$ what proportion/percent of the male children are colorblind?
look at this cross: $x^b x^b$ x $x^b y$ what proportion/percent of the male children are colorblind?
Answer
Explanation:
Step1: Analyze Parental Genotypes
The mother's genotype is ( X^B X^B ) (homozygous dominant for normal vision), and the father's genotype is ( X^b Y ) (hemizygous for colorblindness, as colorblindness is X - linked recessive).
Step2: Determine Gametes
- Mother (( X^B X^B )) can only produce ( X^B ) gametes.
- Father (( X^b Y )) can produce ( X^b ) and ( Y ) gametes.
Step3: Predict Offspring Genotypes
For male children, they inherit the Y chromosome from the father and an X chromosome from the mother. Since the mother only gives ( X^B ), male children will have the genotype ( X^B Y ).
Step4: Determine Colorblindness in Males
Colorblindness (for X - linked recessive) in males requires the ( X^b ) allele. Since male children have ( X^B Y ), they do not have the ( X^b ) allele, so 0% of male children are colorblind.
Answer:
0% (corresponding to the option with "0%")