Ch 12 Cell Cycle PDF
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These notes cover the cell cycle, including key roles, reproduction (sexual and asexual), cellular organization, and genetic material. Topics such as mitosis, meiosis, and the eukaryotic cell cycle are discussed. The notes also include sections on centrosomes and prokaryotic reproduction.
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# Ch 12 Cell Cycle ## 12.1 Cell cycle * Cells come from pre-existing cells. * Individuals can produce more of their own kind. ## Key Roles * New life/organisms * Multi-cellular organisms * Renewable and repair of multi-cellular eukaryotes * Distribution of identical genetic material ## Reproduc...
# Ch 12 Cell Cycle ## 12.1 Cell cycle * Cells come from pre-existing cells. * Individuals can produce more of their own kind. ## Key Roles * New life/organisms * Multi-cellular organisms * Renewable and repair of multi-cellular eukaryotes * Distribution of identical genetic material ## Reproduction ### Sexual * Different from parents (parental cell), better at adapting ### Asexual * Offspring same as parents * Only needs one ## Cellular Organization and Genetic Material * All DNA in cell - genome * May be a single DNA molecule (prokaryotes) * Many DNA molecules (eukaryotes) * DNA molecules are packaged into chromosomes. * Few 100 to 1000 of genes * Gene - section of DNA that codes for something, usually protein. * Chromatin - complex of DNA & proteins, it condenses during cell division. This is then called sister chromatids. * Each of the strands are identical due to DNA process. * Somatic Cells : Non-reproductive cells (all other cells in body) * Gametes: Reproductive cells * Sister chromatids separate into chromosomes & move to the new daughter cells. ## Cell division * Mitosis: Division of genetic material in the nucleus * Cytokinesis: Division of the cytoplasm (everything) * Meiosis: Makes reproductive cells (gametes). * Yields non-identical daughter cells because it has half as many chromosomes as the parent cells. * Haploid (n) * Diploid (2n) * Interphase : 90% of cell cycle (mitosis & Cytokinesis 10%). * Growth and function * G<sub>1</sub> (growth): First gap - metabolic activity/growth * Synthesis: Metabolic activity, growth and DNA replication. * G<sub>2</sub>: Second gap - metabolic activity, growth, and prep for cell division ## Mitosis * Prophase - development of centrosomes * Prometaphase - breakdown of nuclear envelope * Metaphase - organization of sister chromatids lining up in the middle (metaphase plate) * Anaphase - chromosomes are split, movement towards new nucleus form cleavage furrow * Telophase - ## Centrosomes * On the two poles of the cell. * Made of microtubules * Attachment points for sister chromatids to be separated via "walking" & "pulling" mechanisms. ## Bacteria (Prokaryotes) * Undergoes binary fission (asexual process) ## 12.3 Eukaryotic cell cycle is regulated * Molecular control system. * Varies on the type of cell (based on molecular signals & biomolecules) * When it has errors, one example is cancer. * Know checkpoints from fig 12.5.
