The difference between ooganesis and spermatogenesis is

Options

A. oogenesis begins at puberty and spermatogenesis during embryonic development .
B. oogenesis results in formation of four haploid ova from a primary oocyte, while during spematogenesis only one sperm is formed from a primary spermatocyte.
C. the Cytoplasmic division is unequal in oogenesis and equal in spermatogenesis .
D. spermatogenesis is not completed until after fertilization occurs, but oogenesis is completed at the time of birth.

Answer

To solve the question regarding the differences between oogenesis and spermatogenesis, we will analyze each option provided in the question step by step.

### Step-by-Step Solution:

1. **Definition of Oogenesis and Spermatogenesis**:
- Oogenesis is the process of female gamete (ovum) formation, which occurs in the ovaries.
- Spermatogenesis is the process of male gamete (sperm) formation, which occurs in the testes.

2. **Timing of Initiation**:
- Oogenesis begins during fetal development, specifically around the 3rd month of gestation, and continues until menopause.
- Spermatogenesis begins at puberty and continues throughout life.

3. **Outcome of Gamete Formation**:
- In oogenesis, one primary oocyte produces one ovum and typically three polar bodies (which are non-functional).
- In spermatogenesis, one primary spermatocyte produces four functional sperm cells.

4. **Cytoplasmic Division**:
- In oogenesis, the cytoplasmic division is unequal, resulting in one large ovum and smaller polar bodies.
- In spermatogenesis, the cytoplasmic division is equal, resulting in four equally sized sperm cells.

5. **Completion of Process**:
- Oogenesis is completed at the time of ovulation, but the secondary oocyte does not complete meiosis until fertilization occurs.
- Spermatogenesis is a continuous process that results in the production of sperm after puberty.

### Conclusion:
Based on the analysis, the correct differences between oogenesis and spermatogenesis can be summarized as follows:

- Oogenesis begins in the fetal stage and is completed at ovulation, while spermatogenesis begins at puberty and continues throughout life.
- Oogenesis results in one ovum and three polar bodies, whereas spermatogenesis results in four sperm cells.
- Oogenesis involves unequal cytoplasmic division, while spermatogenesis involves equal cytoplasmic division.

### Final Answer:
The correct statement that highlights the difference between oogenesis and spermatogenesis is that oogenesis involves unequal cytoplasmic division, while spermatogenesis involves equal cytoplasmic division.

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