Honors Bio: Reproduction of Cells and Organisms Pt. 1 (cell cycle, mitosis, meiosis)

The Cell Cycle

the life span or generation time of a cell from its beginnings, through its growth and to the time when it will divide

Life span varies according to cell type

Bacteria - 15 mins

Cheek Cells - hours

Stomach lining - days

Muscle cells - years

1st Growth (G1)

cell increases to adult size
performs its cell functions

G0

jumps out of cell cycle
will never divide again

Synthesis

DNA replication
cell is committed to dividing

2nd Growth (G2)

builds up materials needed for cell division before protein synthesis shuts down

Mitosis

“cell division”

a form of asexual reproduction in which a parent cell divides producing two daughter cells having identical genetic components

occurs in somatic cells of multicellular organisms

Parent Cells

original cell that divides to produce daughter cells

Daughter Cells

produced by parent cells, have identical genetic componets

Somatic Cells

normal body building cells/cells not involved in sexual reproduction

Purpose of Mitosis

Unicellular organisms (and some multicellular) - a form of asexual reproduction

Multicellular organisms - make the processes of growth, development and repair possible

What must multicellular and unicellular organisms pass on?

diploid number of chromosomes characteristic of that species

Human 2n=46

Diploid

full set/2n

IPMAT

Interphase (not included in cell division)

Prophase

Metaphase

Anaphase

Telophase

Interphase

parent cell

G1 - growth from previous division

S - DNA replication

G2 - preparation for division

Prophase

old cytoskeleton breaks down

centrioles separate, replicate and migrate to opposite

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