Q.Describe the structure of a mature anther as seen in transverse section.

In transverse section, each microsporangium is bounded by an epidermis, endothecium, 2-3 middle layers, and an innermost tapetum, enclosing sporogenous tissue.

A mature anther, seen in transverse section, is typically bilobed, the two lobes joined by a connective that carries the vascular strand. Each lobe is dithecous, i.e. it contains two microsporangia, so a whole anther commonly has four microsporangia (pollen sacs), one in each corner. Each microsporangium, when young, is surrounded from outside inward by four wall layers: the epidermis (protective, outermost), the endothecium (helps in anther dehiscence by later developing fibrous thickenings), 2-3 middle layers (nutritive, transient), and the innermost tapetum, which nourishes the developing pollen and is progressively absorbed as the pollen matures. Enclosed within each microsporangium is a central mass of sporogenous tissue, whose cells become the pollen mother cells that undergo meiosis to form pollen grains.

Describe the anther's gross bilobed/dithecous organisation first, then the four-layered wall of a single microsporangium from outside inward, ending with the sporogenous tissue at the centre.

Confusing microsporangium (a pollen sac, one of four per anther) with the whole anther; misordering the four wall layers or omitting the tapetum's nutritive role.