Question

Endothecium layer of anther wall plays an important role in dehiscence of anther. The presence of fibrous bands and differential expansion of inner and outer tangential walls of endothecial cells cause dehiscence of anther.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

The Correct Option is A

Microsporangial wall has four types of layersepidermis (common anther covering), endothecium, 1-3 middle layers and tapetum. In a typical anther the endothecial cells develop fibrous thickenings of a-cellulose on the inner and radial walls. Because of the presence of fibrous thickenings, the endothecium is also called fibrous layer. The mature anther dries up. The sterile strip present between the two pollen sacs of each anther lobe disintegrates to form a single cavity. With the loss of water the differentially thickened cells of endothecium contract from their outer thin walls. The latter become concave. It brings their outer radial walls nearer. As a result the endothecium shortens and ruptures the anther lobe wall in the region of stomium.