Question

Question 4. The cells that undergo meiosis to ultimately produce a woman’s eggs are called primary oocytes. A primary oocyte divides to form a secondary oocyte and the first polar body. The secondary oocyte then divides to form the ovum and the second polar body. 4A. Is there any difference between the DNA that is present in the first polar body versus the secondary oocyte? If so, please describe it clearly. 4B. Is there any difference between the DNA that is present in the second polar body versus the ovum? If so, please describe it clearly.

Answer 1

4A. The primary oocyte undergoes meiosis I to produce two cells, the secondary oocyte and a polar body. The number of chrsomoses beceme 23 in both the sec. oocyte and polar body but the sec. oocyte is larger than polar body.

4B. The ovum is developed when secondary oocyte divides, after coming in contact with sperm. This is meiosis II which will keep the number of chromosemes equal.Hence the resulting cells will be, the large ovum which gained nearly all the cytolasm and the samller one, the polar body, which will has almost DNA only. Hence the DNA will be same in both.