3.Human Peripheral blood exposed with tritiated water at variousdoses for 54 hr was examined to observe the chromosome and chromatid abe-rrations at metaphases in the first mitosis of lymphocytes.
6.The paired and replicated chromosomes are called bivalents or tetrads, which have two chromosomes and four chromatids, with one chromosome coming from each parent.
8.So now End 1 is placed near a similar nucleotide sequence, called the homologous sequence, because it's found in the same spot on the homologous sister chromatid.
9.Since homology-directed repair uses a sister chromatid as a template, this is a more reliable repair mechanism than non-homologous end joining because there's no loss of nucleotides.