Question

cell cycle homework questions

1. during which stage of the cell cycle does replication of the dna occur?
2. why is it necessary that the cell copies its dna?
3. why are chromosomes visible during mitosis but not at other times?
4. under a microscope, some cells can appear to be between metaphase and anaphase. explain this observation.
5. which stage or phase of the cell cycle corresponds to each of the descriptions below?

a) a new cell wall begins to form.
b) the membrane of the nucleus dissolves.
c) daughter chromosomes begin to separate.
d) the cell begins to pinch together along its centre.
e) thick chromosome threads are visible in two distinct regions of the cell.
f) the cell grows and copies its dna.

1. create a table to summarize what happens during the three stages of the cell cycle. use the back of this page.
2. biology books used to describe interphase as the ‘resting phase’. based on what we know now, what was wrong with this term?

Explanation:

Question 4 Explanation:

Cells in a population don't divide synchronously. When observing under a microscope, the transition between metaphase (chromosomes aligned at the equator) and anaphase (sister chromatids separating) is a continuous process. Some cells will be caught in the middle of this transition as they progress from metaphase to anaphase, so they appear "between" the two stages.

Answer:

Cells divide asynchronously, so some are in the continuous transition from metaphase (chromosomes at equator) to anaphase (chromatids separating), appearing between these stages.