Tapetum Structure and Bi-nucleate Cells — NEET Biology
✅ Asked in NEET 2025Structure 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. Can you think of how tapetal cells could become bi-nucleate?
NTA tests students on why tapetal cells are bi-nucleate (or multinucleate). These cells develop extra nuclei through mitosis WITHOUT complete cytokinesis—the nucleus divides but the cell doesn't separate, creating one cell with two nuclei. This is crucial because tapetal cells need high metabolic activity to nourish developing pollen grains, and multiple nuclei support this demand. Students mistake this for typical mitosis or think nuclei fuse together. Remember: bi-nucleate cells form when nuclear division occurs without cell division, increasing nuclear:cytoplasmic ratio for enhanced protein synthesis and nutrient provision to pollen.
This paragraph was tested 2 times in NEET.
Given below are two statements: Assertion (A): Cells of the tapetum possess dense cytoplasm and generally have more than one nucleus. Reason (R): Presence of more than one nucleus in the tapetum increases the efficiency of nourishing the developing microspore mother cells. Choose the correct answer:
Which one of the following statements is not true? (NEET 2016)
Through deep analysis of NEET and NTA, 88 of 90 questions from the NEET 2026 paper were matched straight from the MedicNEET Biology question bank.
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