(I) When the anther develops, each cells of
sporogenous tissue undergo melutic divisions to
form microspore tetrads.
(ii) Each one is a microspore mother cell (MMC).
(iii) The process of formnation of microspores from a
pollen mother cell (PMC) through meiosis is called
(iv) The microspores get arranged in a cluster of four
cells and hence are microspore tetrad.
(y) As the anthers mature and dehydrate, the
microspores dissociate from each ether and develop
into pollen grains.
(vi) From each microsporangium, thousands of pollen
grains are formed and released with the dehiscence
Pollen grain (male gametuphyte)
(i) The pollen grains represent the male gametophytes.
(ii) A pollen grain has a two-layered wall namely,
It is the hard outer layer which is made up of
(I) It is the inner, thin and continuous layer which is
made up uf cellulose and pectin.
(ii) A matured pollen grain contains two cells namely,
© Vegetative cell
(d) Generative cell
It is bigger cell having abundant food reserve and a
large irregularly shaped nucleus.
(j) It is small cell that floats in the cytoplasm of the
(ii) It is spindle shaped with dense cytoplasm and a
• Thi pollenn grains are shed at the 2-celled stage in
• In other plants, the generative cell divides
mitotically to give rise to the two male gametes
before pollen grains are shed in 3-celled stage.
• Once they are shed, pollen grains have to land on
the stigma before they lose viability.