4.5 The Cell Cycle - Part I

cell cycle

highly regulated series of events - controls growth/reproduction of eukaryotic cells

somatic cell

cells in body (not reproductive germ cells)

somatic cells makeup

tissues, organs with functions: growth, repairs, maintenance of body

diploid

cells containing 2 sets of chromosomes

diploid in humans

46 chromosomes - 23 from each parent

diploids - genetic info is..

characteristics/traits of individuals

somatic cell examples (3)

skin, muscle, and nerve cells

somatic cells function

divide and replicate during mitosis > identical daughter cells

cell cycle phases (4)

g1, s, g2, mitois

g1 phase (Gap 1) description

cell grows/synthesizes proteins needed for dna replication

s phase (synthesis) description

dna replication > 2 identical copies of genetic material

G2 phase (Gap 2) description

continued growth/syntesis of proteins, checks errors in dna replication/repairs damage

m phase (mitosis)

duplicated chromosomes > 2 daughter cells (process split into 4 phases)

cytokinesis

cytoplasm divides, cell membrane pinches in - daughter cells separate

after cytokinesis/mitosis - daughter cells

enter G1 phase - cycle starts again

duration of cell cycle influences (3)

influenced by external signals, cell type, development stage

mitosis definition

cell division > transmitting chromosomes from one generation to the next

mitosis importance and goal

ensures/creates 2 daughter cells with same genetic info as parent

mitosis stages (4)

prophase, metaphase, anaphase, telophase

prophase description (2)

chromosomes condense and become visible, nuclear membrane breaks down

metaphase description

chromosomes line up at center of cell - spindle fibers attach to each

anaphase description

fibers pull chromosomes apart - pieces move to opposite poles in cell

telopase description

reach opposite poles > nuclear membrane forms around each new pair