FIGURE 18.1. Stages of mitosis. One pair of chromosomes is shown: one chromosome originating from the father (gray), and the matching one from the mother (red).

FIGURE 18.2. Mitosis in cultured breast cancer cells. The upper cell is in prophase. The chromosomes (shown orange) have compacted and are visible as independent structures. The microtubule cytoskeleton (shown green) has not yet reorganized into the mitotic spindle, and microtubules have not invaded the nucleus because the nuclear envelope (not visible in this image) is still intact. The lower cell is in ana-phase. The microtubule cytoskeleton has been reorganized into the mitotic spindle. The two sets of chromosomes are being pulled to opposite spindle poles. Image by Professor David Becker, University College London; used with permission.

FIGURE 18.3. Activation of the anaphase promoting complex and the breakdownof cohesin allows cells to pass the spindle assembly checkpoint.

FIGURE 18.4. Stages of meiosis.

FIGURE 18.5. Chiasmata allow the crossing over of genetic material during prophase I of meiosis.

FIGURE 18.6. The cell division cycle.

FIGURE 18.7. Cdk activities through the cell cycle.

UNFIGURE 18.1.

FIGURE 18.8. How Cdk1 is controlled by cyclin B and phosphorylation in multicellular organisms.

FIGURE 18.9. Retinoblastoma protein Rb sequesters E2F, the critical transcription factor controlling entry into S phase.

FIGURE 18.10. ATM activation stops the cell cycle.

FIGURE 18.11. Recruitment of blood vessels is essential for tumor growth.

FIGURE 18.12. Pathways controlling apoptosis.

FIGURE 18.13. A green fluorescent protein chimera revels cytochrome c translocation in cells. Live human cells (HeLa) were transfected to ex-press a chimaera of cytochrome c and GFP then treated with staurospo-rine, a drug that evokes apoptotic cell death. Data of Choon Hong Tan and Professor Michael Duchen, University College London; used with permission.