Cell Division, Cell Diversity and Cellular Organisation

What Cell Division, Cell Diversity and Cellular Organisation covers

Cell division, cell diversity and cellular organisation closes Module 2. It covers the cell cycle and its checkpoints, the stages of mitosis and meiosis and what each one produces, how cells specialise for particular jobs, the tissues and organs they build, and stem cells.

The 6 subtopics

Each one has its own page.

• The cell cycleThe five stages in order, what happens during G1, S and G2, cytokinesis, and the checkpoints that control progression.Open →
• Mitosis and observing it in root tipsProphase, metaphase, anaphase and telophase, how cytokinesis differs in plant and animal cells, why mitosis matters for growth and repair, and the root tip squash.Open →
• MeiosisHow meiosis halves the chromosome number, the independent assortment and crossing over that generate variation, and the stages of meiosis I and meiosis II in order.Open →
• Specialised cellsGuard cells, root hair cells, palisade cells, sperm cells, neutrophils, erythrocytes and the epithelia — and what fits each for the job it does.Open →
• Tissues, organs and organ systemsWhat separates a tissue from an organ and an organ system, with squamous and ciliated epithelium, cartilage, muscle, xylem and phloem as examples.Open →
• Stem cells and differentiationWhat a stem cell is and what differentiation does, the shared origins of blood cells and of xylem and phloem, meristems, and the medical uses being explored.Open →

What you need to know

Answer each one before you reveal it.

Take Cell Division, Cell Diversity and Cellular Organisation further

The same content, four other ways.

Commonly confused

Pairs that lose marks when they are blurred together.

• Mitosis vs Meiosis

  Mitosis: division producing two genetically identical diploid daughter cells. Meiosis: division producing four genetically different haploid daughter cells.

• Chromatid vs Homologous chromosome

  Chromatid: one of the two identical copies of a chromosome joined at the centromere. Homologous chromosome: one of a matching pair carrying the same genes from each parent.

• Cytokinesis vs Karyokinesis

  Cytokinesis: the division of the cytoplasm after the nucleus has divided. Karyokinesis: the division of the nucleus itself.

Questions from this topic

Each one with the model answer underneath.

1. 1

   Name the five main stages of the cell cycle in order.

   Model answer

   G1, S and G2 — which together make up interphase — then mitosis and cytokinesis.

2. 2

   What occurs during the G1 phase of the cell cycle?

   Model answer

   The cell increases in size and synthesises proteins and organelles.

3. 3

   What is the main event of the S phase?

   Model answer

   DNA replication occurs, producing two identical copies of each chromosome.

4. 4

   What happens during the G2 phase of the cell cycle?

   Model answer

   The cell continues to grow and prepares for mitosis by synthesising proteins needed for cell division.

5. 5

   What is the outcome of mitosis in terms of daughter cells?

   Model answer

   Two genetically identical daughter cells are produced.

6. 6

   Define cytokinesis.

   Model answer

   The division of the cytoplasm following mitosis to form two separate cells.

What is inside Levo

Six ways to work the same material.

Cell Division, Cell Diversity and Cellular Organisation revision questions

What does Cell Division, Cell Diversity and Cellular Organisation cover in OCR A-Level Biology?

6 subtopics: the cell cycle, mitosis and observing it in root tips, meiosis, specialised cells, tissues, organs and organ systems and stem cells and differentiation. Each one has its own page with questions and model answers.

How is Cell Division, Cell Diversity and Cellular Organisation organised?

By the OCR H420 specification, subtopic by subtopic, so it matches the order you are taught it in.