Q.1 A parenchymatous cells having thirty units of DNA, undergoes repeated mitotic division. Assess and explain the DNA units present in the cell(cells) during:- · Prophase · Anaphase · Early telophase · Late telophase · Interphase

ANSWER -

Prophase – It is largest stage of mitosis after interphase, at the time of prophase chromosomes in the beginning appears as five heteropycnotic threads and nucleus look like a ball of wool. The no. of DNA is 60 at this time.

Anaphase – It is the shortest of the mitotic phase, anaphase, occurs when the mutual attachment between two sister chromatids cases at that point the centromere of each chromatid on the metaphase plate separates from its sister centromere and the product of this division, which may now called daughter chromosomes move towards opposite pole of the spindle – total units as DNA = 60. Daugther units towards opposite pole -30-30.

Early telophase – 60 in cell (total) 30-30 towards opposite poles.

Late telophase – 30 in daughter nuclei, 60 in cell because at this time, cell having to daughter nuclei.

Interphase – Having 60 units of DNA due to duplication in S-phase of cell cycle.