Cell Division Lesson 5 PDF

Cell Division  Cell Division Series of growth and development steps a cell undergo to make two new daughter cells Multiplication of the cell number ang growth and development of a multicellular organisms. Cell Cycle Sequence of events involving interphase, cell division (meiosis/mitosis), cell...

Cell Division  Cell Division Series of growth and development steps a cell undergo to make two new daughter cells Multiplication of the cell number ang growth and development of a multicellular organisms. Cell Cycle Sequence of events involving interphase, cell division (meiosis/mitosis), cell growth, cell senescence/aging and cell death 2 types of Cell Division: MITOSIS a process of cells uses to make exact replicas of themselves. Mitosis is observe in almost all the body’s cell, including eyes, skin, hair and muscle cells MEIOSIS This is a cell division of sperm or egg cell in which it produced 4 daughter cells in the end of the process. BINARY FISSION Single –celled organism like bacteria replicate themselves for production. Mitosis type of cell division in which one cell (mother cell) divides to produced two new cells (daughter cell) that are genetically identical to itself INTERPHASE (Resting Phase) Interphase consist of processed called G1, S and G2 phase G1 PHASE G1 phase is the first stage after the division, the cell is recovering from division and conducting most its normal metabolism Synthesis of nucleotides used for the next round of DNA replication The cell grows physical and increase the volume of both protein and organelles The longest part of the cell cycle  Mitosis S PHASE The stage of DNA replication. G2 PHASE During G phase cells prepare for division Protein synthesis happens in this stage. This phase last only 2-for 3 hours The alpha and beta-tubulins necessary for Spindle Microtubules are synthesize Cell produced protein necessary for processing chromosome and breaking down nuclear enveloped. MITOSIS PROPHASE DNA of Chromosome exist as a long, extended double helix associated with histone protein. Genetic material (DNA) condensed. Nucleolus become less distinct and usually completely disappear by the end of prophase Nuclear envelope break to many vesicles, each attached to rough endoplasmic reticulum Microtubules –organizing centers (e.g centrosome) begin to move towards opposite end of the cell, produces and organize the spindle MITOSIS METAPHASE The chromosome move to the center of the cell called METAPHASE PLATE Chromosomes is visible Enzyme “separase” is activated and it digest cohesion: The two chromatids of each chromosome are suddenly free of each other Preparation for pulling of genetic information towards opposite region of the cell MITOSIS ANAPHASE Anaphase is the fourth phase of mitosis. The process that separates the duplicated generic material carried in the nucleus of a parent cell into two identical daughter cell Separation of chromatids and pulled toward opposite region/end of cell MITOSIS TELOPHASE A chromosome approach the ends of the spindle fiber. Fragments of nuclear enveloped appear near them and connect each other. Chromosome become less distinct because it starts to uncoil. The spindle depolymerizes completely and disappears Telophase is the reverse of the prophase. After telophase, CYTOKINESIS occurs MEIOSIS Meiosis involves two round of division without allowing the S phase to occur after the first division, The two division under meiosis are MEIOSIS I and MEIOSIS II, each contains four phases similar to those of Mitosis. The sex cell (gametes) fused together forming zygote which the grows into a new adult. Each gametes contain one complete sets of chromosome. Nuclei cell and organism with one set of chromosomes in each nucleus are said to be HAPLOID. The zygote has two complete set (one from each gamete) so it is DIPLOID. Meiosis occurred only in the production if reproductive cells: Gametes of animals, some algae and fungi but in plant, the meiosis occurs in a few cell of the stamen and ovaries. MEIOSIS I PROPHASE I All event in prophase in mitosis occur in prophase I of meiosis. Nucleolus and nuclear membrane breakdown Centrioles separates Spindle forms Microtubules attach to centromeres Chromosome condense and become visible Divided into 5 stages: Leptotene, Zygotene, Pachyten, Diplotene and Diakinesis MEIOSIS I METAPHASE I Spindle microtubules move the tetrad to the center of the cell, forming the Metaphase Plate MEIOSIS I ANAPHASE I The homologous chromosome separate completely from each other. Moving to opposite end of the spindle. Centromere do not dived, and each chromosome continues to consist of two chromatids MEIOSIS I TELOPHASE I Chromosomes are still doubled (each has two chromatids) and are in G2 state. They do not undergo interphase. Cytokinesis occurs. The process of dividing the cytoplasm of the original cell into 2 daughter cell. MEIOSIS II PROPHASE II DNA replication does not take place in the second step of meiosis. The cell division process immediately begins Prophase II does not include the step of leptotene, zygotene, pachytene, diplotene and diakinesis. MEIOSIS II METAPHASE II The metaphase II, the chromosomes line up individually along the metaphase plate MEIOSIS II ANAPHASE II In Anaphase II, the sister chromatids separates and are pulled toward opposite poles of the cell MEIOSIS II TELOPHASE II In Telophase II, nuclear membrane form around each set of chromosomes and the chromosomes decondense. ASSIGNMENT: Research about different asexual reproduction that occur in cells and organisms. Have a simple yet concise description and explanation to each reproduction.