The second maturation division of the human ovum occurs at the time of :
**Core Concept**
The second maturation division of the human ovum is a critical process in the reproductive cycle, where meiosis II is completed, resulting in the release of a mature ovum. This process is essential for fertilization and subsequent embryonic development.
**Why the Correct Answer is Right**
The second maturation division occurs approximately 24 hours after the first meiotic division, coinciding with ovulation. During this time, the ovum undergoes a series of changes, including the formation of a secondary oocyte and the release of the first polar body. The completion of meiosis II results in the formation of a mature ovum, which is then released into the fallopian tube, where it can be fertilized by a sperm.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the first maturation division, not the second, occurs before ovulation.
**Option B:** This option is incorrect because the second maturation division is a meiotic process that occurs after the first meiotic division, not during the follicular phase of the menstrual cycle.
**Option C:** This option is incorrect because the completion of meiosis II occurs after ovulation, not during the luteal phase of the menstrual cycle.
**Clinical Pearl / High-Yield Fact**
The timing of the second maturation division is critical for fertilization, as it coincides with ovulation and the release of the mature ovum into the fallopian tube.
**Correct Answer:** C. 24 hours after the first meiotic division.