Question: First meiotic division is completed in which of the following follicle?
A At the time of copulation within fallopian tube
B After formation of ovum within the ovary
C At the time of fertilization within ampulla
D Within tertiary follicle prior to ovulation
Answer: Within tertiary follicle prior to ovulation
| Aspect | Description |
| Initiation | The first meiotic division of the primary oocyte initiates during fetal development and is arrested in prophase I before birth. |
| Location | This process takes place within the ovaries of the female reproductive system. |
| Resumption of Meiosis | The first meiotic division resumes within a tertiary (Graafian) follicle shortly before ovulation. |
| Key Event | · Homologous chromosomes undergo recombination and crossing over during prophase I. · Reduction division occurs during the first meiotic division, leading to the formation of two haploid cells, but one of them is much larger and called a secondary oocyte. |
| Result of the First Meiotic Division | The first meiotic division produces a secondary oocyte and a smaller polar body. |
| Status After the First Division | The secondary oocyte is arrested in metaphase II of meiosis until fertilization. |
| Significance | The secondary oocyte is the cell that can be fertilized by a sperm cell, and upon fertilization, it completes the second meiotic division to form a mature ovum. |
| Key Function | Ensures the generation of haploid gametes for fertilization, as it reduces the chromosome number by half. |
| Control Mechanisms | Various hormonal signals and environmental cues regulate the resumption of meiosis and the timing of ovulation. |