A chromosome with two equal arms is

Options

A. Sub-metacentric
B. Metacentric
C. Telocentric
D. Acrocentric

Answer

To answer the question "A chromosome with two equal arms is," we need to analyze the types of chromosomes based on the position of the centromere. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand Chromosome Structure
- Chromosomes are structures within cells that contain DNA. They are typically shaped like an "X" when they are duplicated and ready for cell division.
- Each chromosome has a centromere, which is the region where the two chromatids are joined.

### Step 2: Identify Types of Chromosomes
- Chromosomes can be classified based on the position of the centromere:
1. **Metacentric**: The centromere is located in the middle, resulting in two equal arms.
2. **Submetacentric**: The centromere is slightly off-center, leading to one shorter arm and one longer arm.
3. **Acrocentric**: The centromere is located closer to one end, resulting in one very short arm and one very long arm.
4. **Telocentric**: The centromere is at one end of the chromosome, resulting in one arm.

### Step 3: Analyze Each Option
- **Telocentric**: This type has arms that are not equal and forms a V shape. **(Incorrect)**
- **Acrocentric**: This type has one long arm and one short arm. **(Incorrect)**
- **Submetacentric**: This type has one long arm and one short arm, though the difference is less pronounced than in acrocentric. **(Incorrect)**
- **Metacentric**: This type has two equal arms on either side of the centromere. **(Correct)**

### Step 4: Conclusion
- The chromosome with two equal arms is classified as **metacentric**.

### Final Answer
A chromosome with two equal arms is **metacentric**.

---