Chromatid

A: The center of the two chromosomes that holds them together. The centromeres split during anaphase 2

B: The finches of the Galapagos Islands showed speciation after being isolated on different islands. Adapted to the different food sources on the different islands after a long period of time by changing the shape of their beaks.

C: Testes or ovaries of the male or female reproductive organs

D: Either of the two strands joined together by a single centromere, formed from the duplication of the chromosome during the early stages of cell division and then separate to become individual chromosome during the late stages of cell division.