Question

During microsporogenesis, meiosis occurs in
(a) Endothecium
(b) Microspore mother cells
(c) Microspore tetrads
(d) Pollen grains

Answer 1

Hint: The cells which undergo meiosis in microsporogenesis give rise to microspore tetrads. They are also known as Pollen mother cells (PMC). They reside in the Pollen sac of the anther.

Complete answer:
During microsporogenesis, meiosis occurs in microspore mother cells. When the anther is young, a group of compactly arranged homogenous cells occupies the centre of each microsporangium. These centrally placed cells within the microsporangium form the ‘sporogenous tissue’.
Microsporogenesis: As each cell of the sporogenous tissue is capable of giving rise to a microspore tetrad, each one is considered potential pollen. ‘Microsporogenesis’ is the process of generation of microspores from a pollen mother cell (PMC) through meiosis. As microspores are formed, they are arranged in a cluster of four cells–'the microspore tetrad'.
- As the anthers mature and dehydrate, the microspores break away from each other and develop into ‘pollen grains’.
- Several thousands of microspores or pollen grains are formed inside each microsporangium. They are then released with the dehiscence of the anther.
- In a transverse section, the outline of a typical microsporangium appears near-circular. It is generally surrounded by four wall layers namely the epidermis, endothecium, middle layers and the tapetum.
- The innermost wall layer is the tapetum. It nourishes the developing pollen grains. Cells of the tapetum possess dense cytoplasm and are generally multinucleated.
So, the correct answer is ‘(b) Microspore mother cells’.

Note:
- As the anther develops, the cells of the sporogenous tissue undergo simultaneous meiotic divisions to form ‘microspore tetrads’.
- The pollen grains represent the male gametophytes.
- Endothecium along with the other outer two walls performs the function of protection and helps in dehiscence of anther to release the pollen.