2.1.6 Cell Division – The Cell Cycle

Question 1

What three phases does the cell cycle consist of?

Answer 1

Interphase
Mitosis (M phase)
Cytokinesis

Question 2

List in order the stages of interphase.

Answer 2

G1 phase (gap 1)
G0 phase
S phase – Synthesis pahe
G2 phase (gap 2)

Question 3

What happens during interphase?

Answer 3

• The cell carries out normal functions, but also prepares to divide
• The cell’s DNA is unravelled and replicated to double its genetic content
• The organelles are replicated so it has spare ones
• Increased respiration so ATP stores are increased

Question 4

What are the two main checkpoints in interphase?

Answer 4

The G1 checkpoint and the G2 checkpoint.

Question 5

What are the four purposes of the checkpoints in the cell cycle?

Answer 5

• Ensure the cell cycle can’t be reversed
• Prevent uncontrolled division that could cause tumours
• Ensure DNA is only duplicated once in each cycle
  Detect and repair any damage caused to the DNA

Question 6

What happens if DNA damage is detected at the G2 checkpoint?

Answer 6

The cell cycle is halted and the cell tries to repair the damaged DNA.

Question 7

What takes place during mitosis?

Answer 7

Nuclear division which is split into four stages- prophase/ metaphase/ anaphase/ telophase.

Question 8

List the four events that take place inside the cell at the G1 phase of the cell cycle.

Answer 8

• Organelles duplicate
• Cells grow and increase in size
• Protein synthesis
• Transcription of genes to make RNA

Question 9

Which process takes place in the cell during the S phase?

Answer 9

DNA replication

Question 10

What does the term cytokinesis mean?

Answer 10

Where the cytoplasm divides after nuclear division, resulting in two new daughter cells.

Question 11

What is apoptosis?

Answer 11

Programmed cell death.