Read the passage and answer the following questions:
A typical microsporangium, when observed in a transverse section, has a nearly circular shape. It is typically surrounded by four layers of walls: the epidermis, endothecium, middle layers, and the tapetum. The outer three wall layers serve to protect the microsporangium and aid in the anther's opening to release the pollen. The innermost wall layer, known as the tapetum, provides nourishment to the developing pollen grains. Tapetum cells are characterized by their dense cytoplasm and often contain multiple nuclei. In angiosperms, an anther usually consists of two lobes, each with two theca, making it dithecous. The theca are often separated by a longitudinal groove. The anther itself has a tetragonal shape with four microsporangia situated at its corners, two in each lobe. These microsporangia undergo further development and transform into pollen sacs.
What is a characteristic feature of tapetum cells?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → They often contain more than one nucleus.
The passage states that “Tapetum cells are characterized by their dense cytoplasm and often contain multiple nuclei.” It also states that the tapetum is the innermost wall layer and that it provides nourishment to the developing pollen grains.
Option (1) They have a sparse cytoplasm. — Incorrect. The passage says the cytoplasm of tapetal cells is dense, not sparse.
Option (2) They often contain more than one nucleus. — Correct. Tapetal cells often contain more than one nucleus; they are generally bi-nucleate.
Option (3) They are the outermost cells of the microsporangium. — Incorrect. The tapetum is the innermost wall layer. The outermost layer is the epidermis.
Option (4) They are responsible for anther dehiscence. — Incorrect. Anther dehiscence is helped by the outer three wall layers (epidermis, endothecium and middle layers). The tapetum nourishes the pollen grains.