The shorter and longer arms of à submetaces chromosome are referred to as

Options

A. S-arm and I-arm respectively
B. p-arm and q-arm respectively
C. q-arm and p-arm respectively
D. m-arm and n-arm respectively

Answer

To answer the question regarding the shorter and longer arms of a submetacentric chromosome, we can follow these steps:

### Step-by-step Solution:

1. **Understanding Chromosome Structure**:
- Chromosomes are composed of two chromatids joined at a region called the centromere. The position of the centromere determines the shape of the chromosome.

2. **Types of Chromosomes**:
- There are four main types of chromosomes based on the position of the centromere:
- Metacentric
- Submetacentric
- Acrocentric
- Telocentric

3. **Focusing on Submetacentric Chromosomes**:
- In a submetacentric chromosome, the centromere is located slightly off-center. This results in two arms of unequal length.

4. **Identifying the Arms**:
- The shorter arm of a submetacentric chromosome is referred to as the **P-arm** (petit arm).
- The longer arm is referred to as the **Q-arm** (the next letter in the alphabet after P).

5. **Conclusion**:
- Therefore, in a submetacentric chromosome, the shorter arm is called the P-arm and the longer arm is called the Q-arm.

### Final Answer:
The shorter arm of a submetacentric chromosome is referred to as the **P-arm**, and the longer arm is referred to as the **Q-arm**.

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