Question

Polar bodies are produced during the formation of

• A. Sperm
• B. Oogonium
• C. Spermatocytes
• D. Secondary oocyte

Answer 1

Answer: (D)

Secondary oocyte

During the development of the foetus, many oogonia are produced which undergo mitosis and form primary oocytes which remain at prophase of meiosis I throughout the childhood. Primary oocytes are enclosed by a single layer of cells, the granulosa cells and form structures known as primordial follicles. During woman's fertile years, one primordial follicle per month develops into a mature follicle, known a Graafian follicle. It contains a secondary oocyte and the first polar body, formed when the primary oocyte divides by meiosis I. The secondary oocyte is haploid. The second meiotic division proceeds as far as metaphase but does not continue until a sperm fuses with the oocyte. At fertilisation, secondary oocyte undergoes the second meiotic division producing a large cell, the ovum and a second polar body. All polar bodies are small cells.

Hence, the first polar body is produced during the formation of Secondary oocyte.

So, the correct answer is 'Secondary oocyte'.