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

What is the common test to determine the genotype of a hybrid?

Test cross involves

An organism with two identical alleles for a given trait is:

Which of the following is incorrect for garden pea?

When a homozygous tall plant is crossed with a homozygous dwarf plant,what is the percentage of dwarf progeny obtained in the $F_1$ generation by Mendel (in $\%$)?

Vedclass Test Series

Exam Paper Generator

Online Exam Module