A disease is caused by a dominant gene,but it | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(C) Let the dominant gene causing the disease be $A$ and the normal recessive allele be $a$.The man is heterozygous $(Aa)$ and the woman is homozygous

Vedclass · Accepted Answer

$1/10$

Vedclass · Answer

(C) Let the dominant gene causing the disease be $A$ and the normal recessive allele be $a$.The man is heterozygous $(Aa)$ and the woman is homozygous normal $(aa)$.The cross is $Aa 	imes aa$.The offspring genotypes are $50\% Aa$ and $50\% aa$.Only the individuals with the genotype $Aa$ carry the dominant gene for the disease.The probability of a child having the genotype $Aa$ is $1/2$.Since the penetrance of the gene is $20\%$ (or $1/5$),only $20\%$ of the individuals with the genotype $Aa$ will express the disease.Therefore,the proportion of children expected to have the disease is $1/2 	imes 1/5 = 1/10$.

$A$ disease is caused by a dominant gene,but it shows only $20\%$ penetrance. $A$ heterozygous man marries a homozygous normal woman. What proportion of the children in the population is expected to have the disease?

Similar Questions

Mention the contribution of Gregor Mendel. Mention the reasons for his success.

$A$ heritable feature and its detectable variant is known as........

Out of $7$ contrasting trait pairs selected by Mendel,how many traits were dominant and recessive?

Which of the following traits was $NOT$ considered by Mendel in his experiments on pea plants?

Punnett square was developed by

Vedclass Test Series

Exam Paper Generator

Online Exam Module