The mitotic cell cycle：練習題

During which stage of mitosis do the chromosomes align themselves individually along the equator of the spindle?

Which of the following occurs during anaphase of mitosis?

Uncontrolled cell division can lead to the formation of a tumour. Which of the following is the most likely underlying cause of this loss of control in the mitotic cell cycle?

During which stage of mitosis does the nuclear envelope reform around each group of separated daughter chromosomes?

Why is the action of telomeres essential for the continued division of stem cells?

State the name of the organelle composed of microtubules that organizes the mitotic spindle in animal cells.

Outline the sequence of events that occurs to sister chromatids during anaphase of mitosis.

Compare the process of cytokinesis in plant cells and animal cells as the final stage of the mitotic cell cycle.

(a) Explain how uncontrolled mitosis can lead to tumour formation.

(b) Distinguish between a benign tumour and a malignant tumour.

The graph shows the changes in the mass of DNA per nucleus in a mammalian cell over time during one complete cell cycle, starting at time \(t = 0\) hours.

(a) Identify the phases of the cell cycle represented by regions X, Y, and Z.

(b) Explain what is happening to the DNA molecule during region Y.

(c) Explain why the mass of DNA decreases sharply at region W.