Mammary glands in female, moustache and beard in human males are examples of

Options

A. Sex linked traits
B. Sex limited tratis
C. Sex differentiating traits
D. Sex-determining traits

Answer

To solve the question regarding mammary glands in females and moustaches and beards in human males, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Traits**:
- Mammary glands are present in females and are responsible for milk production.
- Moustaches and beards are secondary sexual characteristics found in males.

2. **Classify the Traits**:
- These traits can be classified based on their expression and the influence of sex hormones.
- Mammary glands are influenced by female hormones (like estrogen), while facial hair is influenced by male hormones (like testosterone).

3. **Understand the Terminology**:
- **Sex-linked traits**: Traits whose genes are located on the sex chromosomes (X or Y).
- **Sex-limited traits**: Traits that are expressed in only one sex, even if the genes are present in both sexes.
- **Sex-differentiating traits**: Traits that differentiate between male and female but may not be limited to one sex.
- **Sex-determining traits**: Traits that initiate the development of male or female characteristics during embryonic development.

4. **Analyze the Options**:
- **Sex-linked traits**: Not applicable here, as both traits are not linked to genes on sex chromosomes but rather influenced by hormones.
- **Sex-limited traits**: Correct, as mammary glands are active only in females and moustaches/beards are present only in males.
- **Sex-differentiating traits**: Incorrect, as this term is broader and includes traits that may not be limited to one sex.
- **Sex-determining traits**: Incorrect, as these traits are related to the initial development of sex in embryos.

5. **Conclusion**:
- The correct classification for mammary glands in females and moustaches/beards in males is **sex-limited traits** since they are expressed in only one sex.

### Final Answer:
Mammary glands in females and moustaches and beards in human males are examples of **sex-limited traits**.