Which of the following is the secondary principle of proportion?
1 answer:
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Answer:
A) 50%
B) 25%
C) Same 25%
Explanation:
a) Smith parents should be heterozygous to the eye color gene, this means, they each should carry a copy of the “brown eye” gene (that we will call B), and one of the “blue eyed” one (that we will call b). Since the blue eye is a recessive trait, you can assume that they both inherited b genes to the daughter. If we draw a Punnet square (Bb vs Bb), we will see the possibilities of Smith having a copy of the blue eye gene (Bb), and it is 50%.
b) Again, with a Punnet square (Bb vs bb) we see that the possibility of having a blue eyed baby is 50% IF Smith carries the copy of the b gene. But since that possibility is established to be 50%, therefore the possibility of the baby to have blue eyes is reduced by half to 25%
c) The probability is the same, it does not have an additive effect, so there is no effect on the number of children
