Question

In fully developed male gametophyte the number of nuclei is

• A. 1
• B. 4
• C. 3
• D. 2

Answer 1

Answer: (C)

3

Microspores are the male gametes which undergo division to form haploid male gametes. It is produced by mitotic cell division of spores, which are produced by meiosis in sporophytes. In the anthers of each stamen, there are pollen sacs. Within the pollen sacs, there are microspore mother cells or microsporocytes. These cells undergo meiosis forming microspores. Each microspore by mitosis forms a pollen grain containing one generative cell and one tube cell. The pollen grain is the male gametophyte. When pollination occurs and the pollen grain makes contact with the stigma the tube cell elongates its cytoplasm forming the pollen tube that grows towards the ovary. The generative cell divides forming two sperm nuclei that migrate through the pollen tube.

So, the correct answer is option C.