Females seldom become bald as they lack

Options

A. The gene for baldness
B. Y-chromosome
C. Male sex hormone
D. All the above

Answer

To solve the question "Females seldom become bald as they lack," we need to analyze the options provided and understand the biological mechanisms involved in baldness.

### Step-by-Step Solution:

1. **Understand the Question**: The question asks why females rarely experience baldness compared to males. This requires an understanding of the biological factors that contribute to hair loss.

2. **Identify the Options**: The options given are:
- A) The gene for baldness
- B) Y chromosome
- C) Male sex hormone
- D) All the above

3. **Analyze Each Option**:
- **Option A: The gene for baldness**: While there are genes associated with baldness, both males and females can carry these genes. Thus, this option alone does not explain why females seldom become bald.

- **Option B: Y chromosome**: Females have two X chromosomes (XX) and lack a Y chromosome. However, the absence of a Y chromosome is not the primary reason for the lower incidence of baldness in females.

- **Option C: Male sex hormone**: This is a crucial factor. Male baldness is often linked to the action of dihydrotestosterone (DHT), a derivative of testosterone, which is a male sex hormone. DHT causes hair follicles to miniaturize, leading to hair loss. Females have lower levels of testosterone and, consequently, lower levels of DHT. This is a significant reason why they seldom become bald.

- **Option D: All the above**: Since options A and B do not adequately explain the phenomenon, this option is also incorrect.

4. **Conclusion**: The most accurate answer is **C) Male sex hormone**. Females seldom become bald primarily because they lack significant levels of male sex hormones that contribute to hair loss.

### Final Answer:
**C) Male sex hormone**