GEN BIO REVIEWER.pdf

GEN BIO REVIEWER CELL DIVISION - It's the process by which a cell divides to form two new cells Three types of cell division or cell reproduction in organism Prokaryotes (bacteria) - Binary fission + Divides forming two new identical cells Eukaryotes - Mi...

GEN BIO REVIEWER CELL DIVISION - It's the process by which a cell divides to form two new cells Three types of cell division or cell reproduction in organism Prokaryotes (bacteria) - Binary fission + Divides forming two new identical cells Eukaryotes - Mitosis + Cell or organism growth + Replacement or repair of damaged cells - Meiosis + formation of sex cells, or gametes WHY DO CELLS DIVIDE? Cells divide for growth, development, repair of worn-out tissues and reproduction To facilitate the exchange of materials To control DNA overloading PROKARYOTIC CELL DIVISION 1.Binary Fission Three (3) major steps; DNA Replication + DNA is copied resulting into two identical chromosomes Chromosome Segregation + Chromosomes separate and move towards ends (poles) of cell Cytokinesis (Separation) + Cytoplasm divides forming two (2) cells Each new daughter cell is Genetically Identical to parent cell EUKARYOTIC CELL DIVISION - Cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent cell 1.MITOSIS Two (2) main steps: A. Mitosis + Fours steps; [Prophase>Metaphase>Anaphase>Telophase]  B. Cytokinesis + Cytoplasm divides forming two new daughter cells Each daughter cell is Genetically Identical to parent cell THE CELL CYCLE - The sequence of events from the time a cell first arises as a result of cell division until the time when that cell itself divides. Arise – Divide ❖ This consist of periods of; Growth and Development DNA Replication Preparation For Division The Cell Cycle Consist of two(2) main periods; I.Interphase II.Mitotic Phase CELL CYCLE - Interphase Interphase: period of growth and DNA replication between cell divisions Three (3) phases: G1 Phase ‒Cell increases in size S Phase ‒Replication of DNA ‒Two sister strands of DNA called chromatids are produced G2 Phase - organelle double  - new cytoplasm - all other structures needed for mitosis form CELL CYCLE – Mitotic Phase Mitotic phase is the stage when a cell divides Mitosis – the division of a single nucleus into two genetically identical daughter nuclei This division involves two(2) processes; ‒Division of the nucleus ‒Separation of the cytoplasm and the new nuclei into daughter cells Mitotic Phase Divided into two (2) mitotic phases 1st MP contain four stages (P-MAT) ‒Prophase, metaphase, anaphase and telophase 2nd MP is cytokinesis mitosis 1.Prophase 2.Metaphase 3.Anaphase 4.Telophase