Which of the following is not a correct difference between male and female humans?

Options

A. Spermatogenesis begins in males at puberty, whereas oogenesis begins in females before they are even born.
B. During meiosis, spermatogenesis involves equal cytokinesis whereas oogenesis involves unequal cytokinesis.
C. One primary spermatocyte produces four gametes (sperm) whereas one primary oocyte produces a single ovum.
D. Spermatozoon contributes to the mitochondria of the zygote whereas ovum contributes to the centrioles of the zygote.

Answer

To determine which of the following statements is not a correct difference between male and female humans, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement Analysis**:
- **Statement 1**: "Spermatogenesis begins in males at puberty, whereas oogenesis begins in females before they are even born."
- **Explanation**: Spermatogenesis, the formation of sperm, does indeed begin at puberty in males. Oogenesis, the formation of eggs, starts during embryonic development in females. This statement is correct.

2. **Conclusion for Statement 1**: This statement is a correct difference between males and females.

3. **Statement 2**: "During meiosis, spermatogenesis involves equal cytokinesis."
- **Explanation**: In spermatogenesis, cytokinesis is equal, resulting in four equal-sized sperm cells from one primary spermatocyte. In contrast, oogenesis involves unequal cytokinesis, leading to one large ovum and three smaller polar bodies. This statement is also correct.

4. **Conclusion for Statement 2**: This statement is a correct difference between males and females.

5. **Statement 3**: "One primary spermatocyte produces four gametes, whereas one primary oocyte produces a single ovum."
- **Explanation**: This is accurate; one primary spermatocyte produces four sperm cells, while one primary oocyte produces one ovum and three polar bodies. This statement is correct.

6. **Conclusion for Statement 3**: This statement is a correct difference between males and females.

7. **Statement 4**: "Spermatosoa contribute to mitochondria of the zygote."
- **Explanation**: This statement is incorrect. The mitochondria of the zygote come exclusively from the ovum, not the sperm. The sperm contributes only its nuclear DNA and a few organelles, but not mitochondria. Therefore, this statement is not a correct difference.

8. **Conclusion for Statement 4**: This statement is incorrect and does not represent a valid difference between male and female humans.

### Final Answer:
The statement that is not a correct difference between male and female humans is: **"Spermatosoa contribute to mitochondria of the zygote."**

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