Transcript Cell Cycle
“Cell division is part of the cell cycle” Section 3.2 & 3.3 Do Now • Label the following diagram • 1- chromosome • 2- chromatid • 3- centromere Objectives • Describe the main events of the cell cycle • Differentiate interphase from mitosis • Construct a cell cycle model from paper plates. Cell Cycle • “normal sequence of development and division of a cell” • Two main phases: Interphase & M-phase (Mitosis) Interphase • There is no division in interphase, just growth. G1: organelles duplicate, cell grows S: DNA replicates (is copied) G2: cell grows, prepares to divide M-phase (Mitosis) • Mitosis= “nuclear division” • PMAT+ C • • • • • Prophase Metaphase Anaphase Telophase Cyokinesis Plate Models • You are now going to make a study tool using paper plates. • Follow along while I show you how to fold the plate, use the directions as a guide. • Pass out plates Mitosis • Creates 2 genetically IDENTICAL daughter cells. Prophase • DNA condenses to form chromosomes. • Each chromosome has 2 chromatids and a centromere • The nuclear membrane disappears Metaphase – “Middle” • Chromosomes line up in the middle of the cell at the “equator” Anaphase – “away” • Chromatids split • Spindles pull to opposite sides of the cell AWAY from each other Telophase • 2 Nuclei form • Nuclear membrane forms around each group of chromosomes. • The chromosomes become chromatin again. Cytokinesis • Division of the cytoplasm. • Occurs differently in plant and animal cells. • 2 New daughter cells! Cytokinesis • Animal Cells: • Membrane pinches together and forms a cleavage furrow until the cells separate. Cytokinesis • Plant Cells: • Cell plate forms which becomes the cell wall and divides the two cells. Section 3.3 “Both sexual and asexual reproduction involve cell division” • Eukaryotic cells divide by mitosis and cytokinesis. • Ex: skin cells apart of skin tissue (aren’t independent) • Most unicellular organisms use cell division to reproduce through asexual reproduction. • Asexual Reproduction: one organisms produces one or more new organisms that are identical to itself and that live independently of it Binary Fission • A form of asexual reproduction occurring in prokaryotes. • The parent organism splits in two, creating two independent daughter cells. • Genetically all the same! Budding - Organism develops tiny buds on its body. • Genetic material the same! • Can bud anywhere OR specialized cells in certain parts of the body. • Detaches when it reaches a certain size • Both unicellular and multicellular can reproduce by budding. Hydra Regeneration The process of new tissue growth at sites with wounds or lost limbs. Bacteria Many bacteria have a very short generation time. Some can have a new generation of cells in less than 30 min.