Chimera is produced due to

$A$ : Occasionally mammary glands are functional in males and the condition is called gynaecomastia.

$R$ : Decreased testosterone in later life may also lead to gynaecomastia. It is usually due to perturbation of estrogen to androgen ratio.

Which of the following diseases results from the genetic inability to synthesize a single enzyme?

If interference is complete or cent percent then the frequency of observed double crossover will be

Night blindness is

A diseased man marries a normal woman and they get three daughters and five sons. All the daughters were diseased and sons were normal. The gene of this disease is