Development of the gametophytes

Development of the gametophytes -...

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Development of the gametophytes Haploid  microspores  develop from  microsporocytes  in the anthers and give rise to pollen grains  containing two cells: the  tube cell  and the  generative cell . At about the time of pollination, the latter  cell divides and produces two  sperm . This three-celled pollen grain is the immature male  gametophyte (microgametophyte).  The female gametophyte, the  megagametophyte , develops in the ovary at the same time the male  gametophyte is developing in the anthers. While the process is exceedingly variable among taxa,  about three-quarters of the flowering plants go through the following steps.  One  megasporocyte  is contained in each of the young ovules within the ovaries in the flower buds.  The ovule is attached by a stalk, the  funiculus , to the  placenta  on the ovary wall and, at this stage,  is essentially a lump of tissue, the 
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This note was uploaded on 11/14/2011 for the course BIO 1421 taught by Professor Farr during the Fall '08 term at Texas State.

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