Question

What are chromatids and centromere

Answer 1

chromatids
$each \: of \: the \: two \: \\ thread- \: like \: strands \: \\ into which \: a \: chromosome \: \\ divides \: longitudinally \: \\ during cell \: division. \: Each \: \\ contains \: a \: double \:helix \: \\ of DNA. \:$

The centromere is the constricted point at which the two chromatids forming the chromosome are joined together. See more at meiosis mitosis.