Beard appears only after attaining maturity as the gene

Options

A. Expression is delayed
B. Expression occurs only in presence of male hormones
C. Remains dominant in childhood
D. All the above

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question states that beard growth occurs only after reaching maturity, which implies that there is a genetic basis for this delayed expression.

2. **Identifying the Key Factors**: The primary hormones responsible for beard growth are testosterone and dihydrotestosterone (DHT). Testosterone is produced in higher amounts during puberty, which is when physical maturity is attained.

3. **Role of Hormones**: Testosterone plays a crucial role in the priming of hair follicles, while DHT is responsible for the actual growth of facial hair, including beards. The increase in these hormones during puberty triggers the development of secondary sexual characteristics, including beard growth.

4. **Analyzing the Options**:
- **Delayed Expression**: This option suggests that the gene expression for beard growth is postponed, which is not entirely accurate since the expression occurs at puberty.
- **Expression Occurs Only in the Presence of Male Hormones**: This option correctly identifies that the presence of testosterone and DHT is necessary for beard growth.
- **Remains Dominant in Childhood**: This option is incorrect as the genes responsible for beard growth are not dominant during childhood; they become active during puberty.
- **All of the Above**: Since not all statements are correct, this option is also incorrect.

5. **Conclusion**: Based on the analysis, the correct answer is that beard growth expression occurs only in the presence of male hormones, specifically testosterone and DHT.

**Final Answer**: Expression occurs only in the presence of male hormones.

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