Cellular Division

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What’s Happening in Interphase?

What the cell looks like

Animal Cell

What’s occurring

Slide 27

Sketch the Cell Cycle

Daughter Cells

DNA Copied

Cells Mature

Cells prepare for Division

Cell Divides into Identical cells

Slide 28

Mitosis

Slide 29

Mitosis

Division of the nucleus

Also called karyokinesis

Only occurs in eukaryotes

Has four stages

Doesn’t occur in some cells such as brain cells

Slide 30

Four Mitotic Stages

Prophase

Metaphase

Anaphase

Telophase

Slide 31

Early Prophase

Chromatin in nucleus condenses to form visible chromosomes

Mitotic spindle forms from fibers in cytoskeleton or centrioles (animal)

Chromosomes

Nucleolus

Cytoplasm

Nuclear Membrane

Slide 32

Late Prophase

Nuclear membrane & nucleolus are broken down

Chromosomes continue condensing & are clearly visible

Spindle fibers called kinetochores attach to the centromere of each chromosome

Spindle finishes forming between the poles of the cell

Slide 33

Late Prophase

Nucleus & Nucleolus have disintegrated

Chromosomes

Slide 34

Spindle Fiber attached to Chromosome

Kinetochore Fiber

Chromosome

Slide 35

Review of Prophase

What the cell looks like

What’s happening

Slide 36

Spindle Fibers

The mitotic spindle form from the microtubules in plants and centrioles in animal cells

Polar fibers extend from one pole of the cell to the opposite pole

Kinetochore fibers extend from the pole to the centromere of the chromosome to which they attach

Asters are short fibers radiating from centrioles

Slide 37

Sketch The Spindle

Slide 38

Metaphase

Chromosomes, attached to the kinetochore fibers, move to the center of the cell

Chromosomes are now lined up at the equator

Pole of the Cell