Cell Cycle & Mitosis

Question 1

Define the principles of cell division

Answer 1

• Cell division involves the parent cell dividing to create two identical daughter cells
• Not all cells divide
• Cell division is regulated by a series of complex sequence of events

Question 2

Describe why cells divide

Answer 2

• It is used to grow new tissue and replace damaged or dead cells
• There are two types of cell division: Mitosis & Meiosis
• Mitosis is the division of somatic (body) cells
• Meiosis is the division of gamete (sex cell) production

Question 3

The cell cycle can be divided into what two phases?

Answer 3

• Interphase

- Mitotic phase

Question 4

List the phases of cell division

Answer 4

• Interphase which includes G0, G1, S phase and G2
• Mitotic phase which includes:
  ▫ Prophase
  ▫ Metaphase
  ▫ Anaphase
  ▫ Telophase

Question 5

What is the purpose of cell cycle check points?

Answer 5

To ensure the cell is fit to progress to the next phase, this avoids unhealthy/incomplete cells from dividing

Question 6

What occurs during mitosis

Answer 6

The division of the nucleus

Question 7

What occurs at G0 phase?

Answer 7

Normal cell functions - no division

Question 8

What occurs at G1 phase?

Answer 8

Replication of most organelles and cellular components

Question 9

What occurs at S phase?

Answer 9

Replication of DNA and synthesis of a new set of chromosomes

Question 10

What occurs at G2 phase?

Answer 10

Enzyme and centrisome replication completed as cell is prepared for division

Question 11

Explain the process of DNA replication

Answer 11

• The enzyme helicase unwinds the strands of DNA creating two separate strands
• The enzyme primase builds RNA primers onto the existing DNA strands to give DNA polymerase a place to start building new DNA strands
• DNA polymerase catalyses the addition of free nucleotides to the growing new DNA strands
• The result of this is two identical double helices