The document summarizes key aspects of cell division, including the cell cycle phases and mitosis. It discusses that phase R of the cell cycle is known as replication. Subphases K, L, and M of the cell cycle are known as the phases of interphase, where DNA replication and protein synthesis occur in preparation for cell division. Mitosis is the cell division process that occurs in phase N and has three stages: prophase, metaphase, and anaphase. Meiosis consists of two stages, Meiosis I and Meiosis II. Meiosis I reduces the number of chromosomes by half from diploid to haploid, such as from 4 chromosomes to 2. Meiosis II is similar to mitosis and separates the

1. Chapter 5: Cell Division
Section A
1. Diagram shows the cell cycle of an animal cell
a) (i) Name the phase labeled R in the cell cycle. [1m]
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(ii) What are subphases K, L and M known as? [2m]
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b) Explain the changes which occur in subphases K, L and M [3m]
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c) What is the cell division process that occurs in N? [1m]
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d) Diagram below shows three stages of mitosis, P, Q and R in an animal cell.
i. Name the stages P, Q and R [3m]
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ii. Explain what happens at stage Q. [3m]
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2. iii. State the chromosome behavior at stage P and R [2m]
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Section B
2. Meiosis consists of 2 stages, that are Meiosis I and Meiosis II.
a) Meiosis I reduces the number of chromosomes by half, that is, from diploid to haploid.
Explain this statement if the diploid number is 2n = 4. [8m]
b) Meiosis II is similar to mitosis. Explain the statement beginning with a cell 2n=4 [8m]
c) (i) Explain how crossing over occurs.
(ii) What is the significance of crossing over? [4m]