$A$ : 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.

An organism which receives identical alleles of a particular gene from both parents is

When Mendel self hybridised the $F_{1}$ plants $(RrYy)$, he found that dominant and recessive traits of one character are segregated in a

The character that is expressed in the $F_{1}$-generation is called the

When a diploid female plant is crossed with a tetraploid male, the ploidy of endosperm cells in the resulting seed is