Cellular Reproduction Cell Division cellular material is divided between new daughter cells cellular material is divided between new daughter cells Nuclear division: Mitosis or Meiosis Nuclear division: Mitosis or Meiosis Cytoplasmic division: Cytokinesis Cytoplasmic division: Cytokinesis

Mitosis and Meiosis in the Human Life Cycle

Cell Cycle with Mitosis G1 S G2 cytoplasm doubles chromosomes replicate assembly of components for division cytokinesis P M A T Mitosis Mitosis P = prophase M = metaphase M = metaphase A = anaphase T = telophase Interphase G1 = growth phase 1 S = synthesis phase S = synthesis phase G2 = growth phase 2 Interphase

Applying Your Knowledge A.When does nuclear division occur? B.When are the chromosomes duplicated? C.When do the cytoplasmic contents double? 1.G1 2.S 3.G2 4.Mitosis 5.Cytokinesis

Chromatin is diffuse, individual chromosomes cannot be distinguished. Interphase nucleus nucleolus

Chromosomes condense. Spindle forms. Nucleolus disappears. Nuclear envelope breaks down. Prophase

Each chromosome appears as a pair of chromatids attached at the centromere. chromatid centromereSister Chromatids are held together at their centromeres. chromatid

Chromatid pairs align at the cell equator. Metaphase

Sister chromatids separate and are drawn to opposite poles by spindle fibers. Anaphase

Chromosomes have reached poles of cell. Spindle disperses. Nuclear envelope surrounds chromosomes. Chromosomes become diffuse, nucleolus reforms. Telophase

Telophase + Cytokinesis These phases can overlap in time. New Daughter Cells

Cytokinesis in animal cells Cytokinesis in plant cells

Applying Your Knowledge A.When do chromosomes line up at the cell equator? B.When are sister chromatids first visible? C.When do sister chromatids separate from each other? 1.Prophase 2.Metaphase 3.Anaphase 4.Telophase

Comparing Mitosis and Meiosis MitosisMeiosis Cell type at start Cell type at end Are products identical? (Y/N) Number of cells produced Number of chromosome duplications Pairing of homologues (Y/N) Crossing-over (Y/N) Number of chromosome divisions

Comparing Mitosis and Meiosis MitosisMeiosis Cell type at start DiploidDiploid Cell type at end DiploidHaploid Are products identical? (Y/N) YesNo Number of cells produced TwoFour Number of chromosome duplications prior to OneOne Pairing of homologues (Y/N) NoYes Crossing-over (Y/N) NoYes Number of chromosome divisions OneTwo