Mitosis

Question 1

what occurs prior to mitosis beginning?

Answer 1

before mitosis begins, the DNA in each linear chromosomes replicates to produce two sister chromatids attached to each other by a centromere.

their are still 46 chromosomes (as they are counted by their centromere), however their are 92 sister chromatids.

Question 2

what happens in prophase?

Answer 2

• the centrioles double and move to opposite poles.
• the nuclear membrane breaks down.
• the chromosomes condense and become visible.
• the chromosomes spread out across the cell.

Question 3

what happens in metaphase?

Answer 3

• the chromosomes independently line up on the metaphase plate at the centre of the cell.
• the spindle fibres between the centrioles act as attachment points for the centromere of each chromosome.

Question 4

what happens in anaphase?

Answer 4

• each replicated chromosome divides down the centre

- single chromosomes of each pair are separated to the opposite poles, led by their centromere.

Question 5

what happens in telophase?

Answer 5

• the spindle breaks down
• nuclear membranes form around each set of single chromosomes.
• chromosomes become long and thin.

Question 6

what happens during cytokinesis?

Answer 6

• a lasso of cytoskeleton tightens around the centre of the cell.
• cell membrane’s form around each cell.
• two smaller, genetically identical cells are formed.
• each cell has the diploid number of chromosomes.
• in a plant cell, the golji body is involved in laying down material to make the cell wall.