B5 - Mitosis

Question 1

What is the cell cycle?

Answer 1

Cells divide over and over again.

Question 2

How do the DNA molecules duplicate?

Answer 2

1. A molecule of DNA splits.
2. Bases on free-floating nucleotides pair up with matching based on DNA.
3. Cross links form allowing the nucleotides to join. Two chromosomes produced.

Question 3

Describe the process of mitosis in five steps…

Answer 3

1. The DNA is spread out in long strings.
2. The DNA forms X shaped chromosomes. Each side of the X is a copy of the other.
3. Cell fibres pull apart the chromosomes.
4. Membranes separate the two sets of chromosomes and the cytoplasm divides.
5. The cell divides to form two cells identical to the mother cell.

Question 4

Mitosis is needed because …

Answer 4

This allows cells to divide and produce more cells for growth and repair.