Mitosis Mitosis A form of asexual Reproduction Mitosis

Mitosis!

Mitosis • A form of asexual Reproduction • Mitosis is the process in which the nucleus divides to form two new nuclei #1 and # 2 (Click on Mitosis above for video) 2 2

How do little elephants grow up to be BIG elephants?

Why do animals shed their skin?

Three reasons why cells reproduce by asexual reproduction: 1. Growth 2. Repair 3. Replacement Skin cancer - the abnormal growth of skin cells - most often develops on skin exposed to the sun. Cells that reproduce by asexual reproduction reproduce constantly. #3

#4 & #5 and #6 Genetic material (DNA)is found inside of the cell - nucleus Every human body cell has 46 chromosomes (23 from mom, 23 from dad). DNA is copied during interphase (before mitosis starts) The 4 Steps of mitosis are: › › Prophase Metaphase Anaphase Telophase

The process of asexual reproduction begins after a sperm fertilizes an egg.

Plant and Animal Cells #7 Plant cells have chloroplast (for photosynthesis)-they also have cell walls Plant cells also have large vacuoles to store water Animal cells have no chloroplast or cell wall-contains small vacuoles if any

Plant and Animal Cell

What living things use mitosis? #8 Both plants and animals use mitosis Some unicellular organisms use mitosis to reproduce

Temporary Cell Structures in Mitosis #9 Centrioles, spindle fibers, centromeres are all temporary structures in the cell used for mitosis

Sister Chromatids #10 Chromosome

Centrioles #11 Centrioles move to the opposite ends of the cell and attach to chromosomes by spindle fibers

Animated Mitosis Cycle http: //www. cellsalive. com/mitosis. htm Cell Division occurs in a series of stages, or phases • Interphase (Not a phase of mitosis) • Prophase (step 1) • Metaphase (step 2) • Anaphase (step 3) • Telophase & Cytokinesis (step 4)

Interphase # 12 occurs before mitosis begins Chromosomes are copied (# doubles) • Chromosomes appear as threadlike coils (chromatin) at the start, but each chromosome and its copy(sister chromosome) change to sister chromatids at end of this phase • Nucleus CELL MEMBRANE Cytoplasm Centromere-holds together the sister chromatids

Interphase Animal Cell Plant Cell Photographs from: http: //www. bioweb. uncc. edu/biol 1110/Stages. htm

Prophase 1 st step in Mitosis begins (cell begins to divide) • Centrioles (or poles) appear and begin to move to opposite end of the cell. • Spindle fibers form between the poles. • Sister chromatids Centrioles Spindle fibers

Prophase (draw this) Animal Cell Plant Cell Spindle fibers Centrioles Photographs from: http: //www. bioweb. uncc. edu/biol 1110/Stages. htm

Metaphase 2 nd step in Mitosis • Chromatids (or pairs of chromosomes) attach to the spindle fibers. Draw this Centrioles Spindle fibers

Metaphase Animal Cell Plant Cell Photographs from: http: //www. bioweb. uncc. edu/biol 1110/Stages. htm

Anaphase 3 rd step in Mitosis • Chromatids (or pairs of chromosomes) separate and begin to move to opposite ends of the cell. Draw this but vertically Centrioles Spindle fibers

Anaphase Animal Cell Plant Cell Photographs from: http: //www. bioweb. uncc. edu/biol 1110/Stages. htm

Telophase 4 th step in Mitosis Two new nuclei form. • Chromosomes appear as chromatin (threads rather than rods). • Mitosis ends. • Nuclei Chromatin Nuclei

Telophase (draw this) Animal Cell Plant Cell Photographs from: http: //www. bioweb. uncc. edu/biol 1110/Stages. htm

Cytokinesis occurs after mitosis • Cell membrane moves inward to create two daughter cells – each with its own nucleus with identical chromosomes.

Onion

Plant Mitosis -- Review Interphase Prophase Metaphase Anaphase Telophase Interphase

Phase?

Animal Mitosis -- Review Interphase Prophase Metaphase Anaphase Telophase Interphase

Cell Cycle 30

Mitosis Animation http: //www. cellsalive. com/mitosis. htm