Explain the structure of pollen grains in Angiosperms.

Explanation

Structure of pollen grain : pollen grain is the hapliod unicellular , uninucleated spherical shaped body bounded by outer thick , spiny or reticulate callose wall called exine and inner thin , smoth cellulose wall called exine , thin areas called germ pores are persent Intine encloses peripheral cytoplasm and central nuceleus .
pollen grain repsent the first stage of male gametophyte . Development be pollen grain takes place when it is still present in the anther locule . During the development it divides uneqally into a large vegetative cell and a small generative cell Generative cell then divides and give rise to two .
non - motile male gametes . this takes place either in the pollen grain or in the pollen tube after pollination .