Hormones have the following features:
I. Adenophypophysis produces gonadotropins
II. Besides sex cells , hormones are also produced by testis and ovary
III. Testosterone is produced by Leydig cells
IV. Estrogen is produced by the ovary
Which of the above factors influence secondary sexual characters ?

Options

A. III and IV
B. II, III and IV
C. II and IV
D. All

Answer

To solve the question regarding which features influence secondary sexual characters, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Understanding Secondary Sexual Characteristics**:
- Secondary sexual characteristics are features that differentiate males and females externally, such as the development of facial hair in males and breast development in females.

2. **Analyzing Statement I**:
- **Statement**: Adenohypophysis produces gonadotropins.
- **Explanation**: The adenohypophysis (anterior pituitary) produces hormones like Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH), which are crucial for the functioning of the gonads (testes and ovaries) and influence secondary sexual characteristics.
- **Conclusion**: This statement is true.

3. **Analyzing Statement II**:
- **Statement**: Besides sex cells, hormones are also produced by testis and ovary.
- **Explanation**: The testes produce hormones (androgens) and the ovaries produce hormones (estrogens and progesterone) in addition to producing sex cells (sperms and ova). These hormones are essential for the development of secondary sexual characteristics.
- **Conclusion**: This statement is true.

4. **Analyzing Statement III**:
- **Statement**: Testosterone is produced by Leydig cells.
- **Explanation**: Leydig cells in the testes produce testosterone, which is responsible for male secondary sexual characteristics such as facial hair and deepening of the voice.
- **Conclusion**: This statement is true.

5. **Analyzing Statement IV**:
- **Statement**: Estrogen is produced by the ovary.
- **Explanation**: The ovaries produce estrogen, which is vital for the development of female secondary sexual characteristics, such as breast development and wider hips.
- **Conclusion**: This statement is true.

6. **Final Conclusion**:
- Since all four statements are true and contribute to the development of secondary sexual characteristics, the answer is that all of the above factors influence secondary sexual characters.

### Final Answer:
All of the above statements (I, II, III, and IV) influence secondary sexual characters.

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