Draw a neat, labelled diagram of an animal cell showing the Prophase stage of Mitosis with four chromosomes.

Your diagram must show: • FOUR chromosomes, each as two CHROMATIDS joined at a CENTROMERE • the NUCLEAR MEMBRANE beginning to disintegrate (drawn as a broken line) • the NUCLEOLUS disappearing • two CENTRIOLES moving to opposite poles • SPINDLE FIBRES beginning to form between them • CYTOPLASM and CELL MEMBRANE (no cell wall — this is an animal cell)

Labels required: chromosome, chromatid, centromere, nuclear membrane, centriole, spindle fibre, cell membrane.

THE FOUR INSTRUCTIONS IN THE QUESTION are each worth marks, and each is easy to lose: ANIMAL cell — so NO cell wall, NO chloroplasts, NO large vacuole, and CENTRIOLES must be present. Drawing a cell wall loses the mark outright. PROPHASE — chromosomes visible but NOT yet lined up at the equator (that is metaphase) and NOT separating (anaphase). FOUR chromosomes — count them. Drawing six or "several" loses a mark for not following the instruction. LABELLED — an unlabelled diagram earns very little however well drawn.

WHAT IDENTIFIES PROPHASE: each chromosome is still DOUBLE (two chromatids joined at the centromere), and the nuclear membrane is breaking down. Draw the membrane as a dashed or broken line to show this — it is the clearest way to signal the stage.

Use a sharp pencil, draw large, and place labels outside the diagram with straight lines that do not cross.