Trisomy has chromosome complement of

Options

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

Answer

To solve the question regarding the chromosome complement of Trisomy, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding Trisomy**:
- Trisomy is a genetic condition where there is an extra chromosome present in the organism. This means that instead of the normal number of chromosomes, there is one additional chromosome.

2. **Normal Chromosome Number**:
- The normal chromosome complement for an organism is represented as "2n", where "n" is the number of pairs of chromosomes. For example, in humans, "n" is typically 23, so the normal complement is 46 chromosomes (2n = 46).

3. **Identifying the Change in Chromosome Number**:
- In the case of Trisomy, there is one additional chromosome. Therefore, the total number of chromosomes becomes 2n + 1. This indicates that there are three copies of a particular chromosome instead of the usual two.

4. **Example of Trisomy**:
- A well-known example of Trisomy is Trisomy 21, which is also known as Down syndrome. In this condition, there are three copies of chromosome 21 instead of the normal two.

5. **Conclusion**:
- Therefore, the chromosome complement of Trisomy is expressed as 2n + 1.

### Final Answer:
The chromosome complement of Trisomy is **2n + 1**.

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