Trisomy has a chromosome complement of -

Options

A. `2n-1`
B. `2n + 2`
C. `2n + 3`
D. `2n +1`

Answer

To answer the question "Trisomy has a chromosome complement of -", we need to understand what trisomy means in the context of genetics.

### Step-by-Step Solution:

1. **Understanding Chromosome Number**:
- Humans typically have 46 chromosomes, arranged in 23 pairs. This is known as the diploid number (2n).

2. **Definition of Trisomy**:
- Trisomy is a type of aneuploidy where there is an extra chromosome in addition to the normal diploid set. This means that instead of having two copies of a particular chromosome, there are three.

3. **Chromosome Complement in Trisomy**:
- In the case of trisomy, the chromosome complement is represented as 2n + 1. This indicates that there is one extra chromosome.

4. **Example of Trisomy**:
- A common example of trisomy is Down syndrome, which is caused by an extra copy of chromosome 21. In this case, the chromosome complement would be 47 chromosomes (46 normal + 1 extra).

5. **Final Answer**:
- Therefore, the chromosome complement of trisomy is 47 chromosomes (for humans), which can be expressed as 2n + 1.

### Final Answer:
Trisomy has a chromosome complement of 47 chromosomes (2n + 1).

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