Draw the diagram of a microsporangium and label its wall layers. Write briefly about the wall layers.

Explanation

A typical angiospermics anther is bilobed with each lobe having two theca. The anther is a four sided structure consisting of four microsporangia located at the corners, two in each lobe.
In a transverse section, a typical microsporangium is circular in out line and is surrounded by four wall layers, the a) epidermis b) endothecium, c) walt layers, d) tapetum.
a) Epidermis : The epidermis is one called thick, the cells present between the pollen sacs are the thin walled and their region is called as stomium which is useful for the dehiscence of pollen sacs.
b) Endothecium : Itis present below the epidermis and expands radically with fibrous thickenings, at maturity these cells loose water and contract and help in the dehiscence of pollen sacs.
c)Wall layers : Beneath the Endothecium, there are thin walled cells, arranged in one to five layers, which also help in dehiscence of Anther.
d) Tapetum : The innermost wail layer is Tapetum, the cells are large, with thin cell walls, abundant cytoplasm and have more than one nuclei. Tapetum is a nutritive tissue which nourishes the developing pollen grains.
The centre of the microsporengium consists of sporogeneous tissue, which undergo meiotio divisions to form microspore tetrads. This process is known as Microsporogenesis.