Question

Choose the correct sequence of wall layers in a microsporangium of an angiosperm.

• A. Epidermis, Middle layer, Endothecium, Tapetum
• B. Epidermis, Endothecium, Middle layer, Tapetum
• C. Epidermis, Tapetum, Middle layer, Endothecium
• D. Epidermis, Middle layer, Tapetum, Endothecium

Hint:

Visualize the structure from outside in with the acronym E-E-M-T: Epidermis, Endothecium, Middle layers, Tapetum.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept: The microsporangium (pollen sac) in an angiosperm anther is surrounded by four distinct wall layers that protect and nourish the developing pollen grains.
Step 2: Key Formula or Approach: Recall the anatomical arrangement of the anther wall layers from the outermost periphery to the innermost core.
Step 3: Detailed Explanation: From the outermost surface to the innermost lining, the sequence of layers is as follows:
1. Epidermis: The outermost single layer of protective cells.
2. Endothecium: The layer situated just below the epidermis, usually with fibrous thickenings that aid in anther dehiscence.
3. Middle layers: Consists of 1 to 3 layers of short-lived cells.
4. Tapetum: The innermost layer, which is crucial for providing nourishment to the developing pollen grains.
Therefore, the correct sequence from outside to inside is Epidermis, Endothecium, Middle layers, and Tapetum.
Step 4: Final Answer: The correct sequence is given in option (2).