Biology · Continuity and change

D2.1 — Cell and nuclear division

Biology · SL / HL · syllabus-mapped notes

1. D2.1.1

   Generation of new cells in living organisms by cell division

   Explain that new cells only ever arise by division of a pre-existing cell.

2. D2.1.2

   Cytokinesis as splitting of cytoplasm in a parent cell between daughter cells

   Contrast cytokinesis in animal and plant cells, and explain why they differ.

3. D2.1.3

   Equal and unequal cytokinesis

   Contrast equal and unequal cytokinesis, using budding in yeast and oogenesis.

4. D2.1.4

   Roles of mitosis and meiosis in eukaryotes

   Contrast the roles of mitosis and meiosis, and explain why nuclear division comes first.

5. D2.1.5

   DNA replication as a prerequisite for both mitosis and meiosis

   Explain why DNA replication precedes division, and define chromatid and cohesin.

6. D2.1.6

   Condensation and movement of chromosomes as shared features of mitosis and meiosis

   Explain why chromosomes must condense, and how microtubules move them.

7. D2.1.7

   Phases of mitosis

   Describe the four phases of mitosis and what happens in each.

8. D2.1.8

   Identification of phases of mitosis

   Prepare a root tip squash and identify the phases of mitosis.

9. D2.1.9

   Meiosis as a reduction division

   Explain meiosis as a reduction division, and why gametes must be haploid.

10. D2.1.10

    Down syndrome and non-disjunction

    Explain non-disjunction and how it causes Down syndrome.

11. D2.1.11

    Meiosis as a source of variation

    Explain how crossing over and random orientation of bivalents generate variation.

12. D2.1.12

    Cell proliferation for growth, cell replacement and tissue repair

    Explain cell proliferation in growth, cell replacement and tissue repair.

13. D2.1.13

    Phases of the cell cycle

    Describe the phases of the cell cycle, including G0.

14. D2.1.14

    Cell growth during interphase

    Explain what a cell must double during interphase, and how each organelle is increased.

15. D2.1.15

    Control of the cell cycle using cyclins

    Explain how cyclins and checkpoints control the sequence of the cell cycle.

16. D2.1.16

    Consequences of mutations in genes that control the cell cycle

    Explain how mutations to proto-oncogenes and tumour-suppressor genes cause tumours.

17. D2.1.17

    Differences between tumours in rates of cell division and growth and in the capacity for metastasis and invasion of neighbouring tissue

    Explain how tumours differ in growth rate and capacity for metastasis, and calculate a mitotic index.