2.2: All cells arise from other cells

Question 1

Through what phase does DNA replication happen?

Answer 1

Interphase - S phase

Question 2

What are the three phases of the cell cycle?

Answer 2

interphase, mitosis, cytokinesis

Question 3

What happens in the G1 phase?

Answer 3

Growth

Question 4

What is G2 phase?

Answer 4

Growth and preparation for mitosis

Question 5

What are the four key stages of mitosis?

Answer 5

Prophase, metaphase, anaphase, telophase

Question 6

What is the function of mitosis?

Answer 6

Growth and repair e.g. clonal expansion of B cells

Question 7

Describe prophase

Answer 7

• Nuclear membrane breaks down
• Centrioles move to the end of the poles and make spindle fibres
• Chromosome supercoil and condense to become visible
• Each chromosome appears as two identical sister chromatids joined at the centromere

Question 8

Describe metaphase

Answer 8

• Centrioles complete production of spindle fibres
• Chromosomes attached to spindle fibres by their centromeres
• Chromosomes align down the equator of the cell

Question 9

Describe anaphase

Answer 9

• Spindle fibres contract and shorten
• Centromere splits
• Identical sister chromatids pulled apart to opposite ends of the poles

Question 10

Describe telophase

Answer 10

• Nuclear membrane reforms around chromosomes
• Chromosomes uncoil and become invisible