Solve this:
Q.123. A holandric gene is known for hypertrichosis (long hairs on ears). When a man with hairy ears marries a normal woman, what percentage of their sons would be expected to have hairy ears :-
(1) 100 %
(2) 0 %
(3) 50 %
(4) 25 %

Dear Student, 

Genes located on Y – chromosome are known as holandric genes. Traits linked with holandric genes are called as Y-linkage or holandric inheritance.

Hypertrichosis (long hairs on ears) is Y-linked or holandric trait .
 
Genotype of man with hairy ear = XYH
Genotype of normal woman = XX
 
When,  a man with hairy ears marries a normal woman,


 

Parent Man with hypertrichosis Normal Woman
XYH XX
X  and YH X
 
F1   X YH
X XX  XYH 
Normal female Male with hypertrichosis
X XX  XYH 
Normal female Male with hypertrichosis


Thus , all the sons will be affected . Option (1) is the correct answer.


Regards, 

 

  • 7
What are you looking for?