plz answer this

Asked by satya36 | 8th Sep, 2009, 06:23: PM

Expert Answer:

A pollen grain is deposited on stigma in  2 celled stage i.e.  a small generative cell and a large tube cell. When the pollen grain germinates, the intine grows and comes out in the form of pollen tube through the germ pore of the exine. It carries along with it both generative and tube nuclei. The pollen tube bores its way down the tissue of stigma and style. The generative nucleus then divides to form 2 non-motile haploid male gametes surrounded by a mass of cytoplasm. The tube nucleus gets disorganised sooner or later. Thus the pollen tube contains only 2 cells i.e. the 2 male gametes.


Answered by  | 14th Sep, 2009, 09:45: AM

Queries asked on Sunday & after 7pm from Monday to Saturday will be answered after 12pm the next working day.