Trisomy is represented by

Options

A. (2n -1)
B. (2n -2)
C. (2n +2)
D. (2n + 1)

Answer

To solve the question "Trisomy is represented by", we need to understand what trisomy means in the context of genetics.

### Step-by-Step Solution:

1. **Understanding Chromosome Number**:
- In genetics, the term "n" refers to the number of chromosomes in a haploid set. For humans, the haploid number (n) is 23, so the diploid number (2n) is 46.

2. **Defining Trisomy**:
- Trisomy is a genetic condition where an individual has three copies of a particular chromosome instead of the usual two. This results in a total of one extra chromosome.

3. **Mathematical Representation**:
- If the normal diploid number of chromosomes is represented as 2n, then having one extra chromosome due to trisomy can be represented as 2n + 1. This indicates that there is one additional chromosome.

4. **Identifying the Correct Option**:
- Now, looking at the options provided:
- a) 2n - 1 (This represents one less chromosome, not trisomy)
- b) 2n - 2 (This represents two less chromosomes, not trisomy)
- c) 2n + 2 (This represents two extra chromosomes, which is not trisomy)
- d) 2n + 1 (This represents one extra chromosome, which is the definition of trisomy)

5. **Conclusion**:
- Therefore, the correct representation of trisomy is **2n + 1**.

### Final Answer:
The answer to the question is **2n + 1**.

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