Which of the following is the example of sex-linked disease?

Options

A. AIDS
B. Colour blindness
C. Syphilis
D. Gonorrhoea

Answer

To determine which of the following is an example of a sex-linked disease, we need to analyze each option provided: AIDS, color blindness, syphilis, and gonorrhea.

### Step-by-Step Solution:

1. **Understanding Sex-Linked Diseases**:
- Sex-linked diseases are those that are associated with genes located on the sex chromosomes (X or Y). Most commonly, these diseases are linked to the X chromosome.

2. **Analyzing the Options**:
- **AIDS**: This is caused by the Human Immunodeficiency Virus (HIV) and is classified as a sexually transmitted disease, but it is not a sex-linked disease. It does not involve genes on the sex chromosomes.
- **Color Blindness**: This condition is caused by a defective gene located on the X chromosome. Therefore, it is classified as a sex-linked disease.
- **Syphilis**: This is a sexually transmitted disease caused by the bacterium Treponema pallidum. It is not a genetic disorder and does not involve sex-linked inheritance.
- **Gonorrhea**: This is also a sexually transmitted disease caused by the bacterium Neisseria gonorrhoeae. Similar to syphilis, it is not a genetic disorder and does not involve sex-linked inheritance.

3. **Conclusion**:
- Among the options provided, the only example of a sex-linked disease is **color blindness**.

### Final Answer:
The correct answer is **color blindness**.