Final answer:
A metacentric chromosome (option b) results from an incorrect split of the centromere during meiosis, forming two identical arms. Chromatids, connected at the centromere, separate during anaphase in meiosis.
Step-by-step explanation:
A chromosome that results when the centromere splits in the wrong plane during meiosis, forming identical arms is known as a metacentric chromosome. This type of chromosome has a centromere that is situated in the middle, such that the two arms of the chromosome are of equal length, giving it a symmetrical appearance.
This contrasts with other types of chromosomes based on centromere location, such as telocentric chromosomes (centromere at the end), acrocentric chromosomes (centromere close to the end), and aneuploid chromosomes (abnormal number of chromosomes). Chromatids are the identical strands of a chromosome that are joined together at the centromere before a cell divides. During anaphase of meiosis, the sister chromatids separate from each other as they are pulled towards opposite poles of the cell.