Question

Question 9 of 25

Having a bent thumb is a recessive trait in humans. The trait is controlled by a
single gene. How many recessive alleles must a person have to have a bent
thumb?
A. 1
B. 0
C. 3
D. 2
SUBMIT

Answer 1

A person must have 2 recessive alleles to have a bent thumb.

Step-by-step explanation:

In order to have a bent thumb, a person must have 2 recessive alleles for the trait. A recessive trait is only observed when an individual is homozygous for that trait, meaning they have two copies of the recessive allele. If someone has just one recessive allele and one dominant allele, they are considered heterozygous and will not have a bent thumb.