Chromosomes complement with 2n-1 is calle as

Options

A. Monosomy
B. Nuilliosomy
C. Trisomy
D. Terasomy

Answer

To solve the question "Chromosomes complement with 2n-1 is called as," we need to understand the terms related to chromosome numbers. Let's break it down step by step:

### Step-by-Step Solution:

1. **Understanding Chromosome Number Notation**:
- The notation "2n" refers to the diploid number of chromosomes in a cell, where "n" is the number of distinct chromosomes.
- Therefore, "2n" represents a complete set of chromosomes, while "2n-1" indicates that one chromosome is missing from this complete set.

2. **Identifying the Condition**:
- When we have "2n-1," it signifies that there is a loss of one chromosome from the normal diploid set. This condition is known as monosomy.

3. **Defining Monosomy**:
- Monosomy is a genetic condition where one chromosome from a pair is missing. This can be represented mathematically as "2n-1," where "n" is the number of pairs of chromosomes.

4. **Exploring Other Options**:
- **Nullisomy**: This refers to the loss of both chromosomes of a homologous pair, represented as "2n-2."
- **Trisomy**: This is when there is an extra chromosome, leading to "2n+1."
- **Tetrasomy**: This refers to the gain of an extra pair of chromosomes, represented as "2n+2."

5. **Conclusion**:
- Since "2n-1" corresponds to the loss of one chromosome, the correct answer is **Monosomy**.

### Final Answer:
The chromosome complement with 2n-1 is called **Monosomy**.

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