Module 2 - Cell cycle

Question 1

What is the cell cycle?

Answer 1

• a regulated sequence of events that occurs between one cell division and the next

Question 2

What are the three stages of the cell cycle?

Answer 2

• interphase
• mitosis
• cytokinesis

Question 3

What are the three phases of interphase?

Answer 3

• G1 phase
• S phase
• G2 phase

Question 4

What occurs in G1 phase?

Answer 4

• the cell grows in size
• organelles duplicate
• protein synthesis occurs for enzymes

Question 5

What occurs in the G1 checkpoint?

Answer 5

• DNA is checked to see if it’s damaged
• checks to see if all chemicals needed for DNA replication are present

Question 6

What occurs in the S phase?

Answer 6

• DNA is replicated
• as DNA replicates, DNA polymerase is prone to random spontaneous errors causing mutations in the DNA
• these can either be beneficial, harmful or neutral

Question 7

What could occur before the S phase?

Answer 7

• G0 - resting phase

Question 8

What is G0?

Answer 8

• can be triggered in early G1
• cells that enter here do not go on to replicate
• they either undergo apoptosis, become specialised or become senescent

Question 9

What occurs in the G2 phase?

Answer 9

• cell grows in size
• organelles duplicate
• ATP production increases as protein synthesis for spindle fibres begins

Question 10

What occurs in the G2 checkpoint?

Answer 10

• cell checks whether all the DNA has been replicated without any damage.

Question 11

What is involved in mitosis?

Answer 11

• the duplication and separation of chromosomes to ensure that each new daughter cell receives a complete set of chromosomes and the necessary components to function as a separate cell

Question 12

What are the four stages of mitosis?

Answer 12

• prophase
• metaphase
• anaphase
• telophase

Question 13

What is cytokinesis?

Answer 13

• where the cell completely divides into two daughter cells