Conditions of a karyotype `2n pm 1 and 2n pm 2` are called

Options

A. aneuploidy
B. polyploidy
C. allopolyploidy
D. monosomy

Explanation

To solve the question regarding the conditions of a karyotype represented as `2n±1` and `2n±2`, we will analyze the definitions of the terms provided in the options and identify the correct answer step by step.

### Step-by-Step Solution:

1. **Understanding Karyotype Notation**:
- The notation `2n±1` and `2n±2` refers to the number of chromosomes in a cell. Here, `2n` represents the diploid number of chromosomes, while `±1` and `±2` indicate the addition or loss of one or two chromosomes, respectively.

2. **Defining Aneuploidy**:
- Aneuploidy is a chromosomal condition characterized by an abnormal number of chromosomes in a cell. This can occur due to nondisjunction during cell division, leading to conditions where there is either an extra chromosome (trisomy) or a missing chromosome (monosomy).
- Examples include Down syndrome (trisomy 21) and Turner syndrome (monosomy X).

3. **Examining Other Options**:
- **Polyploidy**: This condition involves having more than two complete sets of chromosomes (e.g., 3n, 4n). It is not applicable here as we are discussing variations of the diploid number.
- **Allopolyploidy**: A type of polyploidy that results from the hybridization of two different species, leading to multiple sets of chromosomes. This does not fit our karyotype conditions.
- **Monosomy**: This specifically refers to the loss of one chromosome from a pair, which is a specific case of aneuploidy but does not encompass the broader definition needed for `2n±2`.

4. **Conclusion**:
- Since `2n±1` and `2n±2` both indicate variations in chromosome number due to the addition or loss of chromosomes, the correct term that describes these conditions is **aneuploidy**.

### Final Answer:
The conditions of a karyotype `2n±1` and `2n±2` are called **aneuploidy**.

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