CELL GROWTH & REPRODUCTION Chapter 8, Section 2

Cell Size Small cells are more efficient Small cells have a greater Surface Area-to-Volume Ratio so that exchange of materials across the plasma membrane is more efficient

Cell Reproduction Chromosomes = condensed DNA, form when cell is ready to divide Made up of 2 halves held together in the center by the centromere

Cell Cycle (Interphase & Mitosis) Cell Cycle = sequence of growth & division of a cell 1. Interphase 2. Cell Division Mitosis Cytokinesis Interphase = growth period, majority of a cell’s life Cells grow (G1) Chromosomes duplicate (S) Prep for division (G2)

Mitosis Mitosis = period of division, 2 daughter cells get formed, each w/ a complete set of chromosomes Divided into 4 Phases

Prophase Chromatin coils into chromosomes Sister Chromatids = two halves of the chromosome, chromatids are genetically identical Nuclear Envelope & Nucleolus break down Centrioles start sending out Spindle Fibers

2. Metaphase Chromosomes line up in the center of the cell Spindle Fibers attach the chromatids

3. Anaphase Separation of Sister Chromatids

4. Telophase Chromatids pulled to opposite ends of the cell Nuclear Envelope & Nucleolus re-form

Cytokinesis Cytokinesis = division of the cytoplas Cleavage Furrow in animals Cell Plate in plants