Male gametes in angiosperms are formed by the division of

What is the primary function of the tapetum in the anther?

Which one of the following is surrounded by a callose wall?

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:

Even after killing the generative cell with a laser beam,the pollen grain of a flowering plant germinates and produces a normal pollen tube because:

In flowering plants,a mature 'male gametophyte' is derived from a 'pollen mother cell' by