Final answer:
A chromosome with two arms of similar length is referred to as metacentric.
Step-by-step explanation:
A chromosome with two arms of similar length is referred to as metacentric. In a karyotype, chromosomes can be organized based on their size and the position of their centromere. A metacentric chromosome has the centromere near its center, resulting in two arms of similar length. This is different from telocentric chromosomes, which have the centromere at one end, acrocentric chromosomes, which have the centromere closer to one end but still have two arms, and telomeric chromosomes, which have only one arm. A metacentric chromosome has the centromere near its center, resulting in two arms of similar length.