Chromosome question cell cycle

Question

The same chromosome can look very different depending on when in the cell cycle it is observed. Why is that? How many DNA molecules does each chromosome contain at its most condensed? Use the following terms in your explanation: chromatin, histone, chromatid, centromere, chromosome.

Answer 1

A condensed chromosome during interphase has compact chromatin where chromosome is tightly bound with histone proteins.

 

As cycle progresses and interphase disappears with onset of prophase, chromosome begins to decondense, DNA molecules unwind and histone binding is not as tight/compact. Eventually, unwound DNA will replicate and chromatids will be visible. Centromere would pull two chromatids on two ends and decondensed chromosome will appear. They would begin to condense in  end of anaphase and telophase and remain condensed as chromatin when cell undergoes cytokinesis to produce two daughter cells.

 

This is the standard mitosis and cell would begins another cycle of growth differentiation and division.

 

Best,