In plants,meiosis occurs in

Given below are two statements: One is labelled as Assertion $(A)$ and the other is labelled as Reason $(R).$
Assertion $(A) :$ Cells of the tapetum possess dense cytoplasm and generally have more than one nucleus.
Reason $(R):$ Presence of more than one nucleus in the tapetum increases the efficiency of nourishing the developing microspore mother cells.
In light of the above statements,choose the most appropriate answer from the options given below:

The two-celled stage of a mature pollen grain consists of:

The male gametophyte of an angiosperm is represented by the . . . . . . .

Which structure of the stamen is long and slender?

Identify '$a$' in the given figure: