Question

At the time of anther dehiscence

• A. Middle layers develop fibrous thickening
• B. Epidermic degenerates
• C. Endothecium develops fibrous thickening
• D. Endothecium degenerates

Answer 1

Answer: (C)

Endothecium develops fibrous thickening

The anther wall comprises four layers - Epidermis, Endothecium, Middle layers and Tapetum. Out of these layers, it is the Endothecium which helps in anther dehiscence.

The cells of endothecium are radially elongated and develop fibrous thickenings which arise from inner tangential walls, at maturity. These fibrous thickenings are made up of alpha cellulose and traces of lignin. The outer tangential walls remain thin. Endothecium has hygroscopic nature. The inner tangential walls are unable to stretch as the anther matures because of fibrous thickenings but the outer walls are thin and they can expand as the anther matures. Due to this uneven and differential expansion of outer and inner tangential walls, and the hygroscopic nature of endothecial cells, the endothecium helps in anther dehiscence at maturity. Therefore, at the time of anther dehiscence, fibrous thickenings are formed in endothecium.

So, the correct answer is C.