2.3.2 - Mitosis

Question 1

what are the four stages of mitosis?

Answer 1

1. Prophase
2. Metaphase
3. Anaphase
4. Telophase

Question 2

what happens in prophase?

Answer 2

• chromosomes coil up
• nucleolus and nuclear membrane breaks down and these centrioles pull apart to form a spindle

(at the beginning of prophase the centromere already attaches the two daughter chromatids together)

Question 3

what happens in Metaphase?

Answer 3

• chromatids jostle about for a position on the metaphase plate of the spindle
• they are lined up along the plate (each centromere associated with a microtubule of the spindle)

Question 4

what happens in Anaphase?

Answer 4

• the centromeres split
• the chromatids from each pair are drawn towards the opposite poles of the cell
• contraction of the overlapping fibres causes the movement of chromatids (energy using process)
• the chromatids rely on the microtubules to move

Question 5

what happens in Telophase?

Answer 5

• spindle fibres break down
• nuclear envelopes form around the two sets of chromosomes
  (nuclei + centrioles are also re-formed)
• chromosomes begin to unravel

Question 6

what is cytokinesis?

Answer 6

• final stage of the cell cycle before it enters interphase again
• division of the cytoplasm at the end of mitosis to produce two independent, genetically identical daughter cells