General Biology

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General Biology
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General Biology Overview

• Genetics
• Origins
• Structure, Function, and Reproduction of Plants
• Ecology

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Cell Division Overview

• History of Mitosis and Chromosomes
• Cell Division in Prokaryotes
• Cell Division in Eukaryotes
• Cytokinesis
• Control of the Cell Cycle

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History of Cell Biology and Division

• Nucleus discovered in 1830s
• Walther Fleming describes mitosis (1880s)
• Theodore Boveri (1891 figure 8-4)

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Bacterial Cell Division

• Most Prokaryotes have a single, circular
  chromosome
• Binary Fission

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Cell Division in Eukaryotes

• more complex (several homologous chromosomes)
• generally takes much longer and is highly
  regulated

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Errors in Figure
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Anaphase

• kinetochore microtubules shorten, bringing each
  chromatid to opposite pole
• centrosomes move apart

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Telophase

• spindle disperses
• chomosomes become diffuse chromatin again
• nuclear membrane forms again

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Cytokinesis

• Is separable from mitosis
• Why is it different in plants as compared to
  animals?
• Animals have a contractile ring pulls to form a
  cleavage furrow
• plants form a cell plate

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Review

• Cell Cycle Stages?
• Stages/Events of Mitosis
• chromatin, chromosome, chromatid, centromere,
  kinetochore, microtubules, MTOC, cytokinesis?

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Henrietta Lacks

• Born in 1920, diagnosed with cervical cancer in
  1951
• HeLa cells grew in culture very vigorously why
  is cell culture important?
• Problems in the 1970s how had this happened?
• Cervical Cancer
• Human papilloma Virus
• Oncogenes

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Cell Cycle Control

• When should cells be stimulated to divide?
• What keeps cells from becoming cancerous?
• Non-cancerous cells are mortal and become
  senescent
• an extremely complex cell division clock
• environmental conditions
• contact inhibition

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Studying the Cell Cycle in Depth

• What drives cells into mitosis?
• Saccharomyces cerevisiae
• synchronous cell populations

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Important Aspects of Cell Cycle Regulation

• division depends upon environmental conditions,
  until Start is passed
• controlled by mitosis promoting factor (MPF)