CO2 Cell Cycle.pdf

Cell Cycle Prepared by: Paul John L. Guzman, LPT LECTURE OBJECTIVES To characterize the phases of the cell cycle and their control points To describe the stages of mitosis To describe the stages of meiosis To explain the significance or applications of...

Cell Cycle Prepared by: Paul John L. Guzman, LPT LECTURE OBJECTIVES To characterize the phases of the cell cycle and their control points To describe the stages of mitosis To describe the stages of meiosis To explain the significance or applications of mitosis and meiosis To identify disorders and diseases that result from the malfunction of the cell during the cell cycle 2  DEFINITION OF TERMS CELL CYCLE a series of events involving growth, synthesis, and regulations in a cell that results in cell division CELL DIVISION reproduction of cells a parent cell produces daughter cells Mason, K. A., Losos, J. B., Duncan. T. Stem Jems/Science Source. Biology 13th Edition 3 PROKARYOTIC EUKARYOTIC CELL DIVISION vs CELL DIVISION 4 Prokaryotic Cell Division 5  BINARY FISSION a process that occurs in bacteria to reproduce themselves clonal – each cell produced by cell division is an identical copy of the original Mason, K. A., Losos, J. B., Duncan. T. Binary Fission. Biology 13th Edition 6  BINARY FISSION 7 Mason, K. A., Losos, J. B., Duncan. T. Binary Fission. Biology 13th Edition Eukaryotic Cell Division 8  EUKARYOTIC CHROMOSOMAL ORGANIZATION Java T Point (2021). Organization of Chromosome. Retrieved on https://www.javatpoint.com/chromosome Slide 9  CHROMOSOMES Humans have 46 chromosomes in 23 nearly identical pairs. Mason, K. A., Losos, J. B., Duncan. T. Binary Fission. Biology 13th Edition 10  CHROMOSOMES Each of the 46 chromosomes contains hundreds to thousands of genes. Genes play important roles in determining how a person’s body grows, develops, and functions. Mason, K. A., Losos, J. B., Duncan. T. Binary Fission. Biology 13th Edition 11  CHROMOSOMES AUTOSOMES numbered chromosomes numbered roughly in relation to their sizes SEX CHROMOSOMES determine the biological sex and sex-linked traits Mason, K. A., Losos, J. B., Duncan. T. Binary Fission. Biology 13th Edition 12  CHROMOSOMES HAPLOID (n) one complete set of chromosomes necessary to define an organism DIPLOID (2n) twice the haploid total number of chromosomes in BioNinja (n.d.). Haploid vs Diploid. Retrieved on https://ib.bioninja.com.au/standard- a cell level/topic-3-genetics/32-chromosomes/diploid-versus-haploid.html 13 Homologous chromosomes are maternal and paternal copies of the same chromosome. Sister chromatids are replicas of a single chromosome held together at their centromeres by cohesion proteins. Mason, K. A., Losos, J. B., Duncan. T. The difference between homologous chromosomes and sister chromatids. Biology 12th Edition 14  KARYOTYPING Chromosomes vary in size, staining properties, centromere, and the relative length of two arms on either side of the centromere. karyotype - particular array of chromosomes an individual organism possesses Mason, K. A., Losos, J. B., Duncan. T. Binary Fission. Biology 13th Edition 15 Overview of the Cell Cycle  Division Phase Time of high metabolic activity Intense Metabolic Activity Cell Cycle Regulation (Checkpoints) DNA replication (Nuclear)  EUKARYOTIC CELL CYCLE The cell cycle is divided into five phases. INTERPHASE ❑ G1 (Gap 1 Phase) ❑ S (Synthesis Phase) ❑ G2 (Gap 2 Phase) M PHASE ❑ Mitosis and Cytokinesis Mason, K. A., Losos, J. B., Duncan. T. The Cell Cycle. Biology 12th Edition 22  EUKARYOTIC CELL CYCLE INTERPHASE G1 (GAP 1 PHASE) primary growth phase of the cell cell performs normal functions cell organelles are duplicated cells grow longest phase Mason, K. A., Losos, J. B., Duncan. T. The Cell Cycle. Biology 12th Edition 23  EUKARYOTIC CELL CYCLE INTERPHASE S (SYNTHESIS PHASE) DNA replication Mason, K. A., Losos, J. B., Duncan. T. The difference between homologous chromosomes and sister chromatids. Biology 12th Edition Mason, K. A., Losos, J. B., Duncan. T. The Cell Cycle. Biology 12th Edition 24  EUKARYOTIC CELL CYCLE INTERPHASE G2 (GAP 2 PHASE) second growth phase double checks replicated chromosome for possible errors cell continues to prepare for mitosis cell produces proteins that will help in sorting the chromosome Mason, K. A., Losos, J. B., Duncan. T. The Cell Cycle. Biology 12th Edition 25  EUKARYOTIC CELL CYCLE M PHASE MITOSIS nuclear division occurs in somatic cells distribute duplicated chromosomes subdivided into five stages CYTOKINESIS division of the cytoplasm results to two daughter cells from one parent cell Mason, K. A., Losos, J. B., Duncan. T. The Cell Cycle. Biology 12th Edition 26 27 REVIEW 28 TRUE OR FALSE 1. Binary fission in prokaryotes requires the assembly of the nuclear envelope. 2. In eukaryotes, chromatin is composed of RNA and proteins. 3. Kinetochore is a structure that functions to connect centromere to microtubules. 4. In eukaryotic cell cycle, the Gap 1 phase double checks replicated chromosomes for possible errors. 5. Homologous chromosomes are maternal and paternal copies of the same chromosome. 6. Mitosis involves diploid somatic cells. 29 Mitosis 30  Chromatin (DNA packed with proteins)  Sister Chromatids  Diploid (2n) Haploid (n) A cell or organism with two A cell or organism with a sets of chromosomes and single set of chromosomes has two copies of its and has one copy of its genome(complete set of genome(complete set of DNA) DNA) Tetrad Overview of the Cell Cycle  Division Phase Time of high metabolic activity Intense Metabolic Activity Cell Cycle Regulation (Checkpoints)  Start or Restriction point DNA replication DNA replication Key players in Cell Cycle Centriole and Spindle Fibers Intense Metabolic Activity  MITOSIS nuclear division occurs in somatic cells a parent cell produces two new daughter cells that are genetically identical distribute duplicated chromosomes so that each daughter cell receives the same complement of chromosomes Reischig, J. (2020). Mitosis. Root Meristem of Onion. Retrieved from https://commons.wikimedia.org/wiki/File:Mitosis_%28261_14%29_Pressed;_ root_meristem_of_onion_%28cells_in_prophase,_anaphase%29.jpg Slide 55 STAGES OF MITOSIS Mason, K. A., Losos, J. B., Duncan. T. Mitosis and Cytokinesis. Biology 12th Edition 56  STAGES OF MITOSIS Prophase chromosomes condense and become visible chromosomes appear as two sister chromatids held together at the centromere cytoskeleton disassembles spindle fibers forms golgi apparatus and ER disperse nuclear envelope breaks down Mason, K. A., Losos, J. B., Duncan. T. Mitosis and Cytokinesis. Biology 12th Edition 57  STAGES OF MITOSIS Prometaphase Chromosomes attach to microtubules at the kinetochore. Chromosomes move to the equator of the cell. Centrosomes move towards opposite poles. Mason, K. A., Losos, J. B., Duncan. T. Mitosis and Cytokinesis. Biology 12th Edition 59  STAGES OF MITOSIS Metaphase All chromosomes are aligned at the equator (metaphase plate) of the cell. Mason, K. A., Losos, J. B., Duncan. T. Mitosis and Cytokinesis. Biology 12th Edition 61 STAGES OF MITOSIS Anaphase Proteins holding the centromeres of sister chromatids are degraded, freeing individual chromosomes. Chromosomes are pulled to opposite poles. Spindle poles move apart. Mason, K. A., Losos, J. B., Duncan. T. Mitosis and Cytokinesis. Biology 12th Edition 63 STAGES OF MITOSIS Telophase Chromosomes are clustered at the opposite poles and decondense. Nuclear envelopes re-form around chromosomes. Golgi apparatus and ER re-form Spindle is disassembled. Mason, K. A., Losos, J. B., Duncan. T. Mitosis and Cytokinesis. Biology 12th Edition 65  IMPORTANCE OF MITOSIS necessary for growth and development of an organism needed to form the more complex structures in an organism such as tissues and organs necessary when an organism needs new and genetically identical cells to replace those that are Reischig, J. (2020). Mitosis. Root Meristem of Onion. Retrieved from https://commons.wikimedia.org/wiki/File:Mitosis_%28261_14%29_Pressed;_ already old, lost, and/or damaged root_meristem_of_onion_%28cells_in_prophase,_anaphase%29.jpg 67 STAGES OF MITOSIS Cytokinesis In animal cells, cleavage furrow forms to divide the cells. In plant cells, cell plate forms to divide the cells. Mason, K. A., Losos, J. B., Duncan. T. Mitosis and Cytokinesis. Biology 12th Edition 68 CHECKPOINTS AND REGULATION OF THE EUKARYOTIC CELL CYCLE 71 Brooker, R. J. (2020). Checkpoints in the cell cycle. Biology 5th Edition REVIEW 72 In which stage of Mitosis do the following scenarios occur? 1. division of the cytoplasm 2. breakdown of nuclear envelope 3. alignment of chromosomes in the equator of the cell 4. chromosomes are pulled to the opposite poles 5. re-formation of nuclear envelope 6. re-assembly of golgi apparatus and endoplasmic reticulum 7. chromosomes condense and become visible 73 Meiosis 74  MEIOSIS type of cell division that occurs in gametes a parent cell produces 4 daughter cells that are genetically unique from each other occurs after a cell finishes the stages of the interphase has two divisions: o Meiosis I o Meiosis II Brooker, R. J. (2020). How the process of meiosis reduces chromosome number. Biology 5th Edition 75 76 77 78 79 80 81 82 83  STAGES OF MEIOSIS I 84 Mason, K. A., Losos, J. B., Duncan. T.. Biology 12th Edition  STAGES OF MEIOSIS II 85 Mason, K. A., Losos, J. B., Duncan. T.. Biology 12th Edition MEIOSIS I: Prophase I Chromosomes begin to condense. Spindle fibers begin to form. Each chromosome consists of two sister chromatids attached at the centromere. Homologous chromosomes form a bivalent through a process called synapsis Crossing over occurs in the chiasmata. Mason, K. A., Losos, J. B., Duncan. T.. Biology 12th Edition 86  SYNAPTONEMAL COMPLEX joins homologous chromosomes (paired homologues, each composed of two sister chromatids) forms bivalent or tetrad Mason, K. A., Losos, J. B., Duncan. T. Formation of a bivalent. Biology 13th Edition 87 88  GENETIC RECOMBINATION crossing over allows homologues to exchange chromosomal material occurs in the chiasmata Brooker, R. J. (2020). Formation of a bivalent and crossing over during meiosis I. Biology 5th Edition 89 90 MEIOSIS I: Metaphase I Pairs of homologous chromosomes randomly align at the equator of the cell. Chiasmata keep homologous pairs together. A kinetochore microtubule from one pole of the cell attaches to one homologue of a chromosome, while a kinetochore from the other pole attaches to the other homologue of a pair. Mason, K. A., Losos, J. B., Duncan. T. Biology 13th Edition 91 MEIOSIS I: Anaphase I Kinetochore microtubules shorten. Homologous pairs are pulled apart. Sister chromatids do not separate. Mason, K. A., Losos, J. B., Duncan. T. Biology 13th Edition 92 MEIOSIS I: Telophase I The separated homologues form a cluster at each pole of the cell. Nuclear envelope re-forms around each daughter cell. Cytokinesis may occur. Resulting cells have half the number of chromosomes of the original cell. Mason, K. A., Losos, J. B., Duncan. T. Biology 13th Edition 93 MEIOSIS II: Prophase II New spindle fibers form in each cell. Nuclear envelope breaks down. Mason, K. A., Losos, J. B., Duncan. T. Biology 13th Edition 94 MEIOSIS II: Metaphase II Chromosomes consisting of sister chromatids joined at the centromere align along the equator (metaphase plate) of each cell. Kinetochore microtubules from opposite poles attach to kinetochores of sister chromatids. Mason, K. A., Losos, J. B., Duncan. T. Biology 13th Edition 95 MEIOSIS II: Anaphase II Kinetochore microtubules shorten. Sister chromatids are pulled to opposite poles of the cells. Mason, K. A., Losos, J. B., Duncan. T. Biology 13th Edition 96 MEIOSIS II: Telophase II Nuclear membranes re-form. Cytokinesis occurs and four haploid cells are formed. No two cells are alike due to the random alignment of homologous pairs at metaphase I and crossing over during prophase I. Mason, K. A., Losos, J. B., Duncan. T. Biology 13th Edition 97 98 99  SEXUAL LIFE CYCLE IN ANIMALS SEXUAL REPRODUCTION reproduction that involves meiosis and fertilization (syngamy) Slide 100 Mason, K. A., Losos, J. B., Duncan. T. The Sexual Life Cycle in Animals. Biology 12th Edition A COMPARISON OF MEIOSIS AND MITOSIS Mason, K. A., Losos, J. B., Duncan. T. A Comparison of Meiosis and Mitosis. Biology 12th Edition 101 102 REVIEW 103 In which stage of meiosis do the following scenarios occur? 1. Bivalents randomly align along the equator of the cell. 104 In which stage of meiosis do the following scenarios occur? 2. Sister chromatids separate and individual chromosomes move toward the poles as kinetochore microtubules shorten. 105 In which stage of meiosis do the following scenarios occur? 3. Sister chromatids align along the equator of the cell. 106 In which stage of meiosis do the following scenarios occur? 4. Homologous chromosomes synapse to form bivalents. 5. Crossing over/genetic recombination 107 TRUE OR FALSE 6. The random alignment of homologous chromosomes during metaphase I of meiosis results in the formation of genetically unique cells. 7. Synaptonemal complex joins homologous chromosomes to form bivalents. 8. Bivalents form during synapsis. 9. Gametes are diploid. 10. After meiosis II, two identical cells are formed. 108 Cancer 109  CANCER Anything that damages DNA, such as environmental factors or UV radiation in sunlight, can lead to mutations. Random mutations arise with each round of DNA replication. If a gene is mutated that encodes one of the proteins involved in cell division, this can lead to uncontrolled growth. Mason, K. A., Losos, J. B., Duncan. T. Lung Cancer Cells.. Biology 12th Edition 110  CANCER acquired condition characterized by uncontrolled cell division may arise from exposure to carcinogens initially diagnosed via the presence of a tumor Mason, K. A., Losos, J. B., Duncan. T. Lung Cancer Cells.. Biology 12th Edition 111 CANCER BENIGN TUMOR excessive proliferation does not spread to other parts of the body MALIGNANT TUMOR can metastasize Brooker, R. J. (2020). Cancer: its typical progression and effects. Biology 5th Edition 112 CANCER PROTO-ONCOGENES normal cellular genes that become oncogenic when mutated only one allele needs to be mutated TUMOR-SUPPRESSOR GENES normal cellular genes that when mutated can lead to cancer both alleles lose function 113 Brooker, R. J. (2020). General Features of a Signal Transduction Pathway involving growth factor that promotes cell division. Biology 5th Edition 114 p53 GENE tumor-suppressor gene which encodes the p53 protein “guardian of the genome” ✓ involved in the G1/S checkpoint ✓ promote DNA repair ✓ promote programmed cell death (apoptosis) When a mutation removes p53 gene function, the cell can proceed through the cell cycle with damaged DNA, leading to further mutations that lead to cancer. 115 116 End of Presentation  REFERENCES ❑ Mason, K. A., Losos, J. B., Duncan, T. D. (2023). Biology, Thirteenth edition, McGraw-Hill LCC ❑ Brooker, R. J., Widmaier, E. P., Graham, L. E., Stiling, P. D. (2021). Principles of Biology, Fifth Edition, McGraw-Hill Education ❑ Biology: The Dynamic Science, 4th ed by Russell, Hertz, & McMillan (2017) ❑ World of the Cell, 8th Ed by Becker, Hardin, Kleinsmith, & Bertoni (2012) 118