Question 14 of 15intermediate💡 UnderstandShort Answer3 marks

Explain the role of tapetum in the formation of pollen-grain wall.

Correct Answer

The tapetum is the innermost wall layer of the microsporangium and plays a vital role in the development of pollen grains. It nourishes the developing pollen grains as they mature from microspores.

The cells of the tapetum possess dense cytoplasm and generally have more than one nucleus, which enables them to provide essential nutrients and materials for pollen grain development.

While the outer three wall layers (epidermis, endothecium, and middle layers) mainly perform protection and help in dehiscence of anther, the tapetum specifically supports the formation and maturation of pollen grains, which develop a two-layered wall consisting of the outer exine (made of sporopollenin) and inner intine (made of cellulose and pectin).

Exercise: EXERCISES | Q: 17 | (Page 31)
For More Understanding

Explanation

The question specifically asks about tapetum's role in pollen-grain wall formation. According to the NCERT context provided, the tapetum is described as the innermost wall layer that nourishes developing pollen grains. The text mentions that tapetal cells have dense cytoplasm and are often bi-nucleate. While the context explicitly states tapetum nourishes developing pollen grains, it does not provide detailed biochemical mechanisms of how tapetum contributes to exine/intine formation. Students should focus on the nourishing role and characteristics of tapetum cells as mentioned in the textbook.

Solution Steps

  1. Step 1: Identify tapetum as the innermost wall layer of microsporangium

  2. Step 2: State its primary function of nourishing developing pollen grains

  3. Step 3: Describe characteristics of tapetal cells (dense cytoplasm, multinucleate)

  4. Step 4: Connect to pollen grain structure (exine and intine layers)

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