The probability of a child with a bent thumb is out of 4 is 50%.
Explanation:
Information given:
dominant gene = straight thumb (genotype TT, Tt)
recessive trait = bent thumb (genotype tt)
from the question genotype of parents can be deduced:
Parent 1 = Tt
parent 2 = tt
from the Punnet square:
T t
t Tt tt
t Tt tt
From the results of Punnet square it is seen that 50% of progeny will be straight thumb and 50% of progeny will be bent thump.
phenotype ratio and genotype ratio = 1:1
There will be 50 % probability that one of their offspring will be with bent thumb.
progeny with bend thump percent = [tex]\frac{progeny with bent thumb}{total number of offspring}[/tex] x100
= 50%.
