Gain or loss of chromosome (s) is called

Options

A. Euploidy
B. Polyploidy
C. Aneuploidy
D. Haploidy

Answer

To solve the question "Gain or loss of chromosome(s) is called," we will analyze the terms provided and identify the correct one.

### Step-by-Step Solution:

1. **Understanding the Terms**:
- We need to first understand what each term means in relation to chromosomes.
- The options given are:
- Uploidy
- Polyploidy
- Aneuploidy
- Haploidy

2. **Defining Each Term**:
- **Uploidy**: This term is not commonly used in genetics and does not specifically refer to gain or loss of chromosomes.
- **Polyploidy**: This refers to a condition where a cell has more than two complete sets of chromosomes. It is not about the gain or loss of individual chromosomes but rather an increase in the entire set.
- **Haploidy**: This refers to a condition where an organism has a single set of chromosomes. It is not about gain or loss but rather a reduction in chromosome number.
- **Aneuploidy**: This is the correct term that refers to the gain or loss of one or more chromosomes from the normal set. It occurs due to nondisjunction during cell division.

3. **Identifying the Correct Answer**:
- Based on the definitions, the term that correctly describes the gain or loss of chromosomes is **Aneuploidy**.

4. **Conclusion**:
- Therefore, the answer to the question is **Aneuploidy**.