B is the correct answer. They can sometimes show an extinction but not always.
I think it’s zero, it might be zero
Answer:
25%
Explanation:
<u>Genotypes and phenotypes:</u>
- SS = straight hair
- CC= curly hair
- SC = wavy hair
- AA or A0= type A blood
- BB or B0= type B blood
- AB = type AB blood
- 00 = type 0 blood
A man with straight hair and A blood has the genotype SS AA or SS A0.
A woman with wavy hair and B blood has the genotype SC BB or SC B0.
Their first child has straight hair and O blood: SS 00
Because the child has type 0 blood, both parents must have a 0 allele, so their genotypes are SS A0 and SC B0.
<u>If their second child is a boy with straight hair, what is the probability that he has A blood?</u>
The hair and blood type genes are independent, so the hair phenotype of the child is irrelevant to determine the probability of him having A blood.
The parental cross for blood type is A0 x B0.
If you do a Punnett Square, you'll get the following offspring:
25% AB, 25% B0, 25% A0 and 25% 00.
The answer is the child has a probability of 25% of having A blood.
