Which of the following order is correct about the wall layers of microsporangium?

The correct answer is Epidermis → Endothecium → Middle layers → Tapetum

Concept:

• A typical angiosperm anther is bilobed with each lobe having two theca, i.e., they are dithecous
• Often a longitudinal groove runs lengthwise separating the theca
• The bilobed nature of an anther is very distinct in the transverse section of the anther.
• The anther is a four-sided (tetragonal) structure consisting of four microsporangia located at the corners, two in each lobe

Explanation:

Structure of microsporangium:

• In a transverse section, a typical microsporangium appears near circular in outline.
• It is generally surrounded by four wall layers the epidermis, endothecium, middle layers and the tapetum.
• The outer three wall layers perform the function of protection and help in dehiscence of anther to release the pollen.
• The innermost wall layer is the tapetum. It nourishes the developing pollen grains.
• Cells of the tapetum possess dense cytoplasm and generally have more than one nucleus.