Edward's syndrome, Patau's syndrome and Down's syndrome are due to
Mutation due to malnutrition
Change in sex chromosomes
Change in autosomes
Change in both sex chromosomes and autosomes
$A$ : 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.
Experimental evidence of chromosomal theory of inheritance was given by
Which one is a sex-linked disease
Frequency of Down’s syndrome increases when the maternal age is
Who has putforth Mendel's conclusions in the form of laws