The genes are present only in males

Options

A. Sexlinked gnes
B. XY linked genes
C. Holandric genes
D. Incompletely sex linked genes

Answer

To solve the question regarding which genes are present only in males, we can follow these steps:

### Step 1: Understand the Question
The question asks about genes that are specifically found in males. This implies we need to identify genes that are linked to male-specific characteristics or are located on chromosomes that are only present in males.

### Step 2: Analyze the Options
We have four options to consider:
- Option A: X-link genes
- Option B: XY-link genes
- Option C: Hollandric genes
- Option D: Incompletely sex-linked genes

### Step 3: Define Each Option
- **X-link genes**: These are genes located on the X chromosome. Both males (XY) and females (XX) have X chromosomes, so these genes are not exclusive to males.
- **XY-link genes**: This term is not commonly used in genetics. It may imply genes associated with the XY chromosome pair, but it doesn't specifically indicate exclusivity to males.
- **Hollandric genes**: These are genes located on the Y chromosome. Since males have one Y chromosome and females do not, these genes are indeed exclusive to males.
- **Incompletely sex-linked genes**: These are genes that may be linked to sex chromosomes but can also be expressed in both sexes, so they are not exclusive to males.

### Step 4: Identify the Correct Answer
Based on the definitions and the exclusivity of the genes to males, the correct answer is **Option C: Hollandric genes**. These genes are present only in males because they are located on the Y chromosome.

### Step 5: Conclusion
Thus, the genes that are present only in males are Hollandric genes.

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