BIOL 1201 Lecture : Lecture 20
Document Summary
Readings: pgs 234-241, 248-250 in campbell biology 9th ed. Continue from mitosis nuclear division in lecture 19. Cytokinesis: cytoplasmic division: animal cell, plant cell. Characteristics: circular chromosome of dna, origin- starting point for replication, no microtubules; points of origin separate, cell wall/plasma membrane growth leads to cell elongation and daughter cells. 12. 15: variation in timing, rate of cell division, controlling cellular checkpoints is crucial to growth, development, maintenance. Chemical signals regulate cell cycle (see experiment with mammalian cells fig. Chemical signals (example: cyclin-dependent kinase (cdk)- enzyme that phosphorylates proteins, cyclins- proteins that activate kinases, cyclin + cdk complex- activated kinase, provides signal to cell (example. Concentrations of cyclin and cyclin-dependent kinase complexes correlate with cell cycle transitions at g2 checkpoint. 13. 2: no genetic variation: clones , reproductive cells have the same number of chromosomes as vegetative cells, multicellular organisms: budding, etc.
