mitosis the key to growth. mitosis - the division of the nucleus into two equal sets of genetic...
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MITOSIS
the key to growth
Mitosis - the division of the nucleus into two equal sets of genetic informationBasically, simple cell division
Mitosis is part of the Cell Cycle
The cell cycle is divided into 5 phases.1. Interphase
2. Prophase
3. Metaphase
4. Anaphase
5. Telophase
**This is a moving, continuous process. Stages are for study.
The Cell Cycle
Interphase
Mitosis
Cytokinesis
Mitosis
Interphase Period of growth and normal
cell activityEvents of Interphase:•90% of the cell life.•DNA is in the form of chromatin.•DNA replicates, making two exact copies of each chromosome.•2 centrioles appear.
Stages of interphase:• G1 (Gap 1) – normal cell growth•S (Synthesis) – DNA synthesis (replication)•G2 (Gap 2) – prepares for cell division
Look for a distinct nucleus
Interphase
Mitosis: Prophase
Three things happen:
Chromatin coils and become visible chromosomes.
The nuclear membrane breaks down and disappears
The spindle fibers & centrioles forms
Mitosis: ProphaseLook for chromosomes in the center
Mitosis: MetaphaseChromosomes line up on the “equator” (in the middle of the cell)
Chromatids attach to the spindle fibers at the centromere
Mitosis: MetaphaseLook for chromosomes lined up on the “equator”
Mitosis: Anaphase
Chromosomes pull apart in opposite directions towards the “poles”
This phase ends when the chromosomes reach the poles.
Mitosis: AnaphaseLook for chromosomes in two groups pulling apart
Mitosis: TelophaseThe fourth and final phase of mitosis
The opposite of Prophase
Chromosomes unwind to form chromatin
Two new nuclei form with new membranes
The spindle disappears
Mitosis: TelophaseLook for two groups of chromosomes with a cell plate or cleavage furrow
CytokinesisThe division of the cytoplasm
Animal cells pinch inward forming a cleavage furrow.
Plant cells divide from the inside towards the outside by forming a cell plate which becomes the cell wall.
Cytokinesis
Animals:Cleavage furrow
Cell plate cell wall
Differences in plant and animal cells:summary
Animals Plants
centrioles no centrioles
cleavage furrow cell plate
cell wall