Question

6. During mitosis cells use changes in the chromosome apparatus to accurately separate their chromatid pairs between two cells.

A. Please explain (and considering making a diagram) of how the spindle microtubules change across the process of mitosis. Please explain how chromosome attached microtubules change across mitosis and add those to your drawing.

B. Please explain where and how changes in polymerization of microtubules drive these changes and how motor proteins function in this process.

C. Please EXPLAIN HOW cells know that the steps in part A have been completed before moving on to the next phase of mitosis.

Answer 1

Ans. A - The primary function of sister chromatids is to pass on a complete set of chromosomes to all the daughter cells formed as a result of cell division. During mitosis, they are attached to each other through the centromere – a stretch of DNA that forms protein complexes.

cyclin and CDk protein complex is present in cell, this protein complex are present in each stage of cell, this protein complex have the function of pushing the cell cycle to next stage, once cell cycle enter to next stage protein complex become inactive, in next stage new cyclin and CDK complex get form.

Ans.B-

Fifteen hours later, the whole process is repeated by the two daughter cells. During interphase, the period between mitoses, chromosomes are decondensed and dispersed.

Ans. C.-

Every cells have some special kind of protein complex, which form after completion of one stage.

This protein complex push to cell cycle in next stage, this proteins are called cyclin and CDK proteins.

If you have any doubt then mention in comment.