MITOSIS VS MEIOSIS :MITOSIS VS MEIOSIS BY BEATRIZ PELAEZ


objectives :objectives Discuss Cell growth & division Explain interphase Explain mitosis Discuss the four stages of mitosis Explain Meiosis What is the purpose of Meiosis


Cell growth & division :Cell growth & division The process by which a cell divides to form two daughter cells.


TWO TYPES OF CELL DIVISION :TWO TYPES OF CELL DIVISION MITOSIS MEIOSIS Is the process of cell division for the purpose of reproduction Is the process of cell division in which the nucleus and the cytoplasm divide to form two identical cells


MITOSIS VS MEIOSIS :MITOSIS VS MEIOSIS mitosis Daughter cells’ chromosomes number = parent cell’ chromosome H chromosomes don’t pair No crossing over MEIOSIS Daughter cells’ chromosomes number half of parent cells’ chromosome H chromosomes pair at prophase I Crossing over occurs


MITOSIS VS MEIOSIS :MITOSIS VS MEIOSIS mitosis Identical daughter cell Two daughter cells from one parent cell One nuclear division Occurs in normal body cells for repair and growth MEIOSIS Variated daughter cell four daughter cells from one parent cell two nuclear division Occurs in gonads during gamete formation


interphase :interphase Interphase refers to all stages of the cell cycle other than mitosis. The chromosomes are not visible and the DNA appears as uncoiled chromatin


Slide 9:G1 = gap or growth S = synthesis – replicates its DNA G2 = the gap or growth phase following the replication of DNA and prior to mitosis


MITOSIS :MITOSIS PROPHASE METAPHASE ANAPHASE TELOPHASE TWO NEW CELLS


Slide 11:prophase the first stage of mitosis the chromosomes condense and become visible the spindle apparatus forms at opposite poles of the cell


Slide 12:METAPHASE Chromosomes line up at the EQUATOR. Centromere of each chromosome attached to a spindle fiber.


Anaphase: :Anaphase: Each centromere splits, pulling apart the chromatids to opposite poles of the cell. Separated, the chromosomes are now known as daughter chromosomes.


Telophase :Telophase the separated chromosomes reach the opposite poles the nuclei of the daughter cells form around the two sets of chromosomes


Slide 16:MEIOSIS


SUMMARY :SUMMARY A new cell is produced from its parent cell, when this daughter cell divides it becomes two new cells. Before a dividing cell enters mitosis, it undergoes a period of growth called interphase The process in cell division by which the nucleus divides, typically consisting of four stages, prophase, metaphase, anaphase, and telophase


questions :questions True or false Mitosis is the process of cell division for the purpose of reproduction Meiosis is the process of cell division in which the nucleus and the cytoplasm divide to form two identical cells. Name the four stages of mitosis After the four stages what is NORMALLY formed? What is the difference between mitosis and meiosis.


questions :questions Before a dividing cell enters mitosis it goes through a growth period called _______ 7. 8. 9. 10.


ANSWERS :ANSWERS FALSE FALSE prophase, metaphase, anaphase, and telophase normally resulting in two new cells formed by the original cell. 1 replication and 2 cell divisions, producing four haploid (n) cell


answers :answers Interphase. Prophase Anaphase Telophase metaphase


references :references Davis, Bernard E Textbook of Microbiology. NY: Hoeber Medical DivisionHarper & Row Publishers. http://porpax.bio.miami.edu/~cmallery/150/mitosis/mitosis.htm#five Forshier, Steve Essentials of radiation biology and protection. NY: by Delmar, a division of Thomson Learning