The mule is a

Who proposed the term 'Allelomorph'

When two genetic loci produce identical phenotypes in cis as well as in trans position, they are considered to be

Discontinuous variations are

$A$ : 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.

Genes on same chromosome can be