Cell Division and Inheritance (Part 2) PDF

Cell Division and Inheritance (Part 2) Prepared by: Mr. Jay Flores Tandan Faculty, College Department Centro Escolar Las Piñas Objectives At the end of this unit, the students should be able to: Create a flowchart of the events that happen in the cell cycle Explain the different stages Mitos...

Cell Division and Inheritance (Part 2) Prepared by: Mr. Jay Flores Tandan Faculty, College Department Centro Escolar Las Piñas Objectives At the end of this unit, the students should be able to: Create a flowchart of the events that happen in the cell cycle Explain the different stages Mitosis  Cell cycle -includes cell’s preparation for and its actual division -major stages: Interphase (non-dividing) and Mitosis (dividing)  Interphase -occurs between the end of cytokinesis and the beginning of the next mitotic division -divided into G1, S and G2 phases; also includes G0 Human Genetics: Concepts and Applications 12th Ed. by Lewis, p. 27 G1 (first growth or gap) phase -early growth phase -production of carbohydrates, proteins, and lipids needed for building extra cell membrane  G1 (first growth or gap) phase -preparatory stage of DNA replication (synthesis of transfer RNA, ribosomes, messenger RNA and many enzymes)  G0 -quiet phase -point in G1 wherein the cell can exit the cell cycle -the cell here is alive, keeps it specialized characteristics but it does not replicate its DNA or divide; other possible fate of the cell - proceed to  S (DNA synthesis) phase -growth continues; DNA replication DNA replication -results to a pair of identical sister Chromatid -attaches to its other copy or sister at a constriction point (Centromere); bounded to each centromere is a disk of protein (Kinetochore), serves as attachment sites for the microtubules Zoology 10th Ed. by Miller and Harley, p. 39 Zoology 10th Ed. by Miller and Harley, p. 39 Human Genetics: Concepts and Applications 12th Ed. by Lewis, p. 28 G2 (second growth or gap) phase -assembly and storage of membranes under the plasma membrane -replication of mitochondria and other organelles, synthesis of microtubules and protein (mitotic spindle fibers’ components) and chromosome condensation -preparation for chromosome separation during mitosis (synthesis of spindle and aster proteins) Interphase -nucleus contains chromatin fibers M (mitotic) phase -distribution of chromosomes between two daughter cells; division of the cytoplasm (Cytokinesis) Human Genetics: Concepts and Applications 12th Ed. by Lewis, p. 28 Prophase -begins when chromosomes become visible as threadlike structures; nuclear envelope and nucleoli disintegrate; two centriole pairs move apart and eventually migrate at the opposite poles of the cell by the end of prophase  Between the centrioles, the microtubules form a spindle of fibers that extends from pole to pole Mitotic spindle -collective term for centrioles, asters, Human Genetics: Concepts and Applications 12th Ed. by Lewis, p. 29  Prometaphase -a second group of microtubules attach at one end (to the kinetochore of each chromatid) and its other end (to one of the poles of the cell)  Metaphase -chromatids begin to align at the center of the cell; centromeres divide and detach the two sister chromatids from each other (called as Daughter chromosomes) Integrated Principles of Zoology 17th Ed. by Hickman Jr. et al., p. 50  Anaphase -each daughter chromosome moves toward its respective poles (due to shortening of the microtubules in the spindle fiber and activity of kinetochore’s motor proteins)  Telophase -mitotic spindle disassembles -nuclear envelope reforms (around each set of chromosomes) and nucleoli resynthesize -chromosomes begin to uncoil -cell begins to pinch in the middle Cytokinesis -cytoplasm divides; starts sometime during late anaphase or early telophase -contracting belt of microfilaments (Contractile ring) pinches the plasma membrane to form the Cleavage furrow; furrow deepens, and two new, genetically identical daughter cells form Integrated Principles of Zoology 17th Ed. by Hickman Jr. et al., p. 52 Introductory Botany: Plants, People, and the Environment 2nd Ed. By Berg, p. 244 Cell Cycle and Mitosis https://www.youtube.com/watch?v=WAGjRco olds References Books Klug, William S. Concepts of Genetics. 12th ed. USA: Pearson Education, Inc., 2019 Lewis, Ricki. Human Genetics: Concepts and Applications. 12th ed. USA: McGraw-Hill Education, 2018 Books (For Zoology/Foundations of Zoology/General Zoology) Dela Paz, Reynaldo M., Annabelle A. Herrera and Edna A. Amparado. Lecture Notes on Zoology. Quezon City: ACLC Trading Enterprises, 2006 Hickman Jr., Cleveland P. et al. Integrated Principles of Zoology. 17th ed. New York: McGraw- Hill Education, 2017 Miller, Stephen A. and John P. Harley. Zoology.10th ed. New York: McGraw-Hill Education, 2016