SPANGLER SCIENCE

MITOSIS
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CELL CYCLE: GROWTH AND DIVISION

INTERPHASE: Prepatory stage for cell division. Three things happen: 1. The cell increases in size (grows) 

2. Organelles duplicate within the cell

3. Chromotin condense to chromosomes.

4. Centrioles  are copied in cytoplasm.


MITOSIS: Second stage for cell duplication. The duplication of chromosomes.

*DNA distributed into two cells by seperation of chromosomes.

*creation of two nuclei

PHASE 1: PROPHASE   *Centrioles appear with fibers

*nuclear membrane breaks down 

*chromosomes coil to chromotids with centrioles


PHASE 2: METAPHASE   * centrioles at opposite ends of the cell

*fibers connect to centromere of the chromatids

*chromatids line up in the center (row)


PHASE 3: ANAPHASE   * centromeres split 

*chromatids go to opposite sides of the cell (2 daughter chromosomes)


PHASE 4: TELOPHASE  * new nuclear membrane forms around two sets of chromosomes

*fibers disappear



CYTOKINESIS:  Cell membrane starts to pinch inward to create two seperate cells. The cytoplasm divides, the organells go to each new cell. This process begins at the same time as telophase. The final stage of the cell cycle.


*Animal cells- pinch in at membrane

*Plant cells-cell plate formed in the middle and grows outwards.




BINARY FISSION: Prokaryotic cells only have one chromosome. Asexual.






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PH Active Art- Cell Cycle

DNA: Double Helix - twisted ladder    Carries all cell’s instructions (genetic material)

Structure of nucleotides of a sugar, phosphate & base. Bases are nitrogen, four kinds are adenine, thymine, guanine & cytosine. The bases only pair off A=T & C=G, they can not pair off any other way.

The structure of DNA was only discovered 50 years ago.


CHROMOSOMES: Made up of DNA and proteins

number of chromosomes vary with the organism.

condensed chomatin

                                             

CHROMATIN: scattered in the nucleus.

material that contains DNA and genetic info.


CHROMATIDS: sister chromosomes hooked together by centromere during mitosis. Identical rods of chromosomes.


GENE: segment of DNA that codes specific trait

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W.T. EICH INTERMEDIATE