CELL GROWTH REPRODUCTION Chapter 8 Section 2 Cell

CELL GROWTH & REPRODUCTION Chapter 8, Section 2

Cell Size § Small cells are more efficient § Small cells have a greater Surface Areato-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, 2 parts § 1. Interphase § 2. Cell Division § Mitosis § Cytokinesis § 1. Interphase = growth period, majority of a cell’s life § § § Cells grow (G 1) Chromosomes duplicate (S) Prep for division (G 2)

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

Phases of Mitosis § 1. 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 = division of the cytoplasm § Cleavage Furrow in animals § Cell Plate in plants

Cancer (Ch. 9, Sec. 3) § Results from uncontrolled cell division § If the DNA of a cell is damaged/altered, regulation of cell division can be affected § Environmental factors can damage cells

Practice § Lung cancer is the leading cause of death by cancer for males and females. Explain how this statistic can be easily reduced.