BIOD 101 Module 4 Portage Learning Exam With Complete Solutions

BIOD 101 Module 4 Portage Learning Exam With Complete Solutions Chromosomes - structures of packaged chromatin complexes Somatic cell - All of the body's cells except gametes Number of chromosomes in each somatic cell - 46 (23 pairs) Cell cycle - Process of parent cell replicating its genetic info and dividing into 2 new daughter cells cytokinesis - division of the cytoplasm interphase - G1, S, G2 phases. 90% of cycle time. Gap phase 1 - First phase, growth phase Messenger RNA (mRNA) - transfers genetic info from DNA to ribosomes site of protein synthesis - ribosomes S phase - DNA duplication phase, lasts 10-12 hours G2 phase - Second growth phase, when synthesis of organelles and proteins needed for mitosis occurs. Lasts 4-6 hours. centrosome - region that organizes microtubules for cell division centriole - short cylindrical protein filaments made of tubulin. Plays role in formation of mitotic spindle. Chromatin fibers become more coiled and densely packed, sister chromatids are joined at the centromere and have an X shape. - Condensation stage of prophase Cohesions - proteins holding sister chromatids together Microtubules begin moving to opposite poles of cell - Centrosome movement stage of prophase aster - Radial microtubule proteins extending from each centrosome Cytoskeletal apparatus composed of different types of microtubules to separate sister chromatids. Includes centrosomes, spindle microtubules, and asters - Mitotic spindle Synthesizes ribosomal subunits, breaks down during prophase - Nucleolus Characteristics of Prophase - 1. Condensation of chromatin fibers 2. Centrosome movement 3. Formation of mitotic spindle 4. Breakdown of nucleolus Characteristics of Prometaphase - 1. Continued chromatin condensation 2. Changes to nuclear envelope 3. reorganization and changes to mitotic spindle kinetochore - structured region used for microtubule attachment, face in opposite directions Characteristics of metaphase - 1. polarization of centrosomes 2. chromosome alignment along equatorial line of cell 3. kinetochore attachment metaphase plate - symmetrical plane across cell formed by centrosome placement Characteristics of anaphase - 1. Separation of sister chromatids 2. movement of separated chromatids toward centrosome poles 3. elongation of cell Characteristics of telophase - 1. reformation of nuclei, some organelles, and nuceoli 2. decondensing of chromosomes 3. dissolution of spindle microtubules 4. mitotic phase completion 5. Cytokinesis Cleavage - Process through which cytokinesis occurs in animal cells Cleavage furrow - visible groove along metphase plate of cell. Actin and myosin interact to contract actin ring like a drawstring and divide the cell Cell cycle control system - molecular surveillance mechanisms that can halt the cell cycle or allow it to proceed