Question

Arm ratio in metacentric condition is

• A. 1:1
• B. 1:2
• C. 1:3
• D. 2:3

Answer 1

The correct option is A 1:1

The arm ratio in metacentric condition is 1:1. These are X-shaped chromosomes, with the centromere in the middle, so that, the two arms of the chromosomes are almost equal. A chromosome is metacentric, if its two arms are roughly equal in length. In a normal human karyotype, two chromosomes are considered metacentric: chromosomes 1 and 3. In some cases, a metacentric chromosome is formed by balanced translocation: the fusion of two acrocentric chromosomes to form one metacentric chromosome.