3.2.2 All cells arise from other cells

Question 1

What is mitosis?

Answer 1

Mitosis is the dividing of the parent cells to produce two genetically identical daughter cells.

Question 2

Give the two main functions of mitosis.

Answer 2

• for growth of multicellular organisms

- for repairing damaged tissues

Question 3

List the four stages of mitosis.

Answer 3

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

Question 4

Give one example of how a cancer treatment can target the cell cycle.

Answer 4

• Chemotherapy can prevent the synthesis of enzymes needed for DNA replication, therefore disrupting the synthesis phase and forcing the cell to kill itself.
• Radiation and some drugs can damage DNA. If severe damage is detected, the cell will kill itself.

Question 5

What is an interphase?

Answer 5

• A part of the cell cycle that consists of a period of cell growth and DNA replication.
• It’s separated into three separate growth stages: Gap Phase 1, Synthesis, and Gap Phase 2.

Question 6

What happens during the Prophase stage?

Answer 6

• The chromosomes condense.
• Centrioles move to opposite poles (sides) to form a network of protein fibres called spindles.
• The nuclear envelope breaks down.

Question 7

What happens during the Metaphase stage?

Answer 7

• The chromosomes line up along the equator (middle) of the cell.
• The chromosomes are attached to the spindle by their centromere.

Question 8

What happens during the Anaphase stage?

Answer 8

• The centromeres divide, separating each pair of sister chromatids.
• The spindles contract, pulling chromatics to opposite poles of the spindle.

Question 9

What happens during the Telophase stage?

Answer 9

• The chromatids reach the opposite poles of the spindle.
• They uncoil (becoming long and thin).
• A nuclear envelope forms around each group of chromosomes, forming 2 nuclei.

Question 10

What is cytokinesis?

Answer 10

The dividing of cells (during mitosis) to form two daughter cells.