CELL DIVISION AND MITOSIS

Think about it…  Does an organism get larger because each cell increases in size or because it produces more of them?

Why cells need to be small  -  -  Would the size of Munster’s library be adequate in Chicago? NO… not enough info to go around!  -  -

Division of the Cell  Cell Division – -  -

Asexual Reproduction  Asexual Reproduction – -  For many single celled organisms, cell division is the only form of reproduction.  -

Asexual Reproduction  -.  Ex: Hydra

Sexual Reproduction  Sexual Reproduction – -  -  Most animals and plants and some single-celled organisms.  -

THE PROCESS OF CELL DIVISION

What happens when you are done growing?  Does cell division STOP?

Chromosomes  Chromosome = -  -  Even small cells like E-Coli have A LOT of DNA  Total amount of DNA = 1.6mm  1,000 times longer than the cell!  -  -

Prokaryotic Chromosomes ------

Eukaryotic Chromosomes  -  The number of chromosomes depends on the organism.  Fruit flies = 8 chromosomes per cell  Human cells = 46 chromosomes per cell  Carrot cells = 18 chromosomes per cell  Dog cells = 78 chromosomes per cell

 -  Histones = -  Chromatin = -  -

The Cell Cycle  -  - Prokaryotic Cell Cycle  - Results in the production of 2 genetically identical daughter cells

Eukaryotic Cell Cycle  Consists of 4 phases  -  Interphase – -  G1 S G2  G1phase = -  S phase = -  G2 = -  M phase = -  2 main stages: -

Mitosis  Mitosis – -  Four phases  -  Depending on the cell mitosis can last a few minutes to several days

Prophase  The first phase of mitosis  Usually the longest phase  What happens during prophase?  -

Metaphase  Second phase in mitosis  Generally the shortest phase  What happens during metaphase?  -

Anaphase  3 rd phase of mitosis  What happens during anaphase?  -

Telophase  The fourth phase of mitosis  What happens during telophase?  -

Cytokinesis  Cytokinesis = -  -

Animal Verse Plant Cytokinesis  -  Anchored to membrane  -  Vesicles with wall building contents in middle  - AnimalPlant