In mammals the female secondary sexual characters are developed mainly by the hormone :-

Options

A. Relaxin
B. Estrogens
C. Progesterone
D. Gonadotropins

Answer

To answer the question regarding which hormone mainly develops female secondary sexual characteristics in mammals, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: We need to identify which hormone is primarily responsible for the development of female secondary sexual characteristics in mammals.

2. **Identify the Options**: The options provided are:
- Relaxin
- Estrogens
- Progesterone
- Gonadotropins

3. **Analyze Each Option**:
- **Relaxin**: This hormone is produced by the ovary and placenta and is mainly involved in preparing the body for childbirth by relaxing pelvic ligaments and widening the cervix. It does not primarily contribute to the development of secondary sexual characteristics.

- **Estrogens**: Estrogens are a group of steroid hormones that play a crucial role in regulating reproductive functions and the development of secondary sexual characteristics in females. These characteristics include breast development, nipple erection, and hair growth in specific areas (underarm and pubic hair). Thus, estrogens are essential for the development of female secondary sexual characteristics.

- **Progesterone**: This hormone is mainly involved in preparing the endometrium for potential pregnancy after ovulation. While it plays a vital role in pregnancy, it does not directly influence the development of secondary sexual characteristics.

- **Gonadotropins**: These are hormones released by the anterior pituitary that stimulate the gonads (ovaries and testes) to produce sex hormones. They are not directly responsible for the development of secondary sexual characteristics.

4. **Conclusion**: After analyzing all the options, it is clear that the hormone responsible for the development of female secondary sexual characteristics in mammals is **Estrogens**.

### Final Answer:
In mammals, the female secondary sexual characters are developed mainly by the hormone **Estrogens**.

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