Chapter 2 Structure of Chromosomes: Cell Cycle and Cell Division Progress Check Page 11 Fill in the blanks. 1. Chromatin fibre is made up of DNA and ……… . Answer Ans. Histones 2. The two sister chromatids of a chromosome are attached to each other at ………. Answer Ans. Centromere 3. The structure of DNA was first discovered by …………. Answer Ans. Rosalind Franklin 4. The three components of a nucleotide are ………….. , …………. and …………….. Answer Ans. phosphate, sugar (pentose) and nitrogenous base 5. DNA strand wound around a histone octamer forms a complex...