The size of ovum is :
**Core Concept**
The size of the ovum, also known as the mature oocyte, is a critical aspect of reproductive physiology. The ovum is released from the ovary during ovulation and is the largest cell in the human body, with a significant impact on fertility and reproductive health.
**Why the Correct Answer is Right**
The mature ovum measures approximately 120-130 micrometers (μm) in diameter, with a slight variation in size depending on the individual. This size is essential for fertilization, as the sperm must be able to penetrate the zona pellucida, a glycoprotein layer surrounding the ovum. The ovum also contains a large amount of cytoplasm, which provides nutrients for the developing embryo after fertilization.
**Why Each Wrong Option is Incorrect**
* **Option A:** 50 μm is too small for a mature ovum, which is not capable of supporting embryonic development.
* **Option B:** 200 μm is significantly larger than the actual size of the ovum, which would not be feasible for the reproductive system.
* **Option C:** 80 μm is closer to the size of a primary oocyte, which is smaller than the mature ovum.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the size of the ovum is critical for fertilization, and any significant variation in size can impact fertility and reproductive health.
**Correct Answer:** C.