Question

Number of nuclei present in the mature male gametophyte of angiosperms is?

• A. One
• B. Two
• C. Three
• D. Many

Answer 1

The correct option is B Two

Pollen grain or the male gametophyte is formed from pollen mother cells through microsporogenesis and microgametogenesis. Each pollen mother cell (PMC) divide by meiosis to form four haploid microspores (this process is called microsporogenesis). Each microspore then develops into pollen grain (this process is called mocrogametogenesis).

Each microspore divides mitotically to form two cells: a large Vegetative cell and a small Generative cell. The generative cell resides within the cytoplasm of the vegetative cell. Later, the generative cell divides to form two sperm cells (i.e. male gametes or the male nuclei). At this stage, pollen grains are said to be 3-celled. If the generative cell divides inside the pollen tube, to form two male gametes the pollen is said to be liberated at 2-celled stage.

Thus, a mature pollen grain will always have 2 nuclei , whether liberated at 2-celled or 3-celled stage.

So, the correct answer is B.