Question

Male gametes are formed by
(a) Pollen cell
(b) Generative cell
(c) Pollen tube cell
(d) Pollen mother cell

Answer 1

Hint:They are the reproductive cell, especially a cell of an angiosperm pollen grain that divides to provide two male gamete nuclei. Upon germination, the tube cell forms the pollen tube through which this cell migrates to enter the ovary.

Complete answer: Male gametes are formed by Generative cells. A typical anther contains four microsporangia. The microsporangia form sacs or pockets within the anther (anther sacs or pollen sacs) . The two separate locules on either side of another may fuse into one locule. Each microsporangium is lined with a nutritive membrane called the tapetum and initially contains diploid pollen mother cells. These undergo meiosis to make haploid spores. The spores may remain attached to every other during a tetrad or separate after meiosis. Each microspore then divides mitotically to make an immature microgametophyte called a pollen grain.
The pollen grain is the male gametophyte. The cell within the pollen grain divides unequally to make two cells called a generative cell and a vegetative cell. The vegetative cell provides nourishment. The generative cell divides mitotically to form the two male gametes. These two male gametes move together with the pollen tube towards the female gametophyte.
The vegetative cell then gives rise to the pollen tube, a tubular protrusion from the pollen grain, which carries the sperm cells within its cytoplasm. Microsporogenesis within another involves the meiotic division of pollen mother cells, which each produce four microspores. So, the right answer is ‘Generative cell’.

Note: Pollen of angiosperms must be transported to the stigma, the receptive surface of the carpel, of a compatible flower, for successful pollination to occur. After coming to the stigma, the pollen grain (an immature microgametophyte) typically completes its development. It may grow a pollen tube and undergo mitosis to provide two sperm nuclei.