Question

The anther wall consists of four wall layers where
A. Endothecium lies inner to middle layers
B. Tapetum lies just inner to endothecium
C. Tapetum lies next to the epidermis
D. Middle layers lie between endothecium and tapetum

Answer 1

The anther wall consists of 4 layers. Each anther lobe develops two pollen sacs. Then, a two-lobed anther develops four pollen sacs that situate at four corners of the anther.

Complete answer: The order of arrangement of the layers is the epidermis, endothecium, middle layer, and tapetum. The middle layers are present between the endothecium and tapetum. The middle layer consists of 2-4 cells. The innermost layer is the tapetum, which delivers nutrition to the evolving pollen cells. The cells of the tapetum can be multinucleated or uninucleated. The outer three layers have a protective function. The tapetum is a specific layer of nutritive cells found within the anther of flowering plants, where it is positioned between the sporogenous tissue and the anther wall.
Different layers of the anther wall include-
a) A single layer of epidermis between, which becomes stretched and shrivels off at maturity.
b) A single layer of endothecium. The cells of endothecium have fibrous thickenings.
c) One to three middle layers. Cells of these layers generally disintegrate in the mature anther.
d) A single layer of the tapetum. The tapetal cells may be uni, bi, or multinucleate and possess dense cytoplasm. The cells of the primary sporogenous layer divide further and give rise to diploid sporogenous tissue.
Hence, the correct option is (D) Middle layers lie between endothecium and tapetum

Note: The anther wall is formed by a specific number of cell layers that originate in the earliest developmental stages. It consists of four layers. Development of pollen sacs begins with the differentiation of archesporial cells in the hypodermal region below epidermis at four corners of the young anther.