Cell Cycle Flashcards
Interphase
the phase when a cell is growing and preparing for cell division; when the cell is not dividing
G1
Gap 1
part of interphase; cell growth/normal cell activity
S
Synthesis
part of interphase; DNA replication
G2
Gap 2
part of interphase; protein + organelle synthesis
G0
Gap 0
outside of the interphase phase; resting/normal cell activity/ the cell isn’t preparing to divide
Mitotic Phase
the cell is dividing; mitosis and cytokinesis
Mitosis
nuclear division
Phases of Mitosis
prophase, metaphase, anaphase, telophase
What happens during prophase?
duplicated chromosomes are condensed more into sister chromatids; nuclear membrane breaks down, nucleolus dissappears; spindle forms; centrioles begin to move to opposite ends
What happens during metaphase?
spindle fibers from each pole of the cell attach to the centromeres; spindle fibers move the chromosomes into a line in the middle
What happens during anaphase?
spindle fibers separate the sister chromatids and move them to opposite ends of the cell; sister chromatids are now considered daughter chromosomes; cell elongates
What happens during telophase?
nuclear membrane reforms; nucleolus becomes visible; chromosomes are unwind into chromatin; animal cell starts to pinch in
Cytokinesis
division of the cell membrane + cytoplasm
Differences of cytokinesis in plant cells and animal cells
plant cells - cell plate
animal cells - cleavage furrow
Cytokinesis in Animal cells
cell membrane draws inward and cytoplasm is pinched into two equal parts; each cell contains a nucleus and cytoplasmic organelles
Cytokinesis in Plant cells
cell plate forms in the middle of the divided nuclei; slowly develops into a cell membrane that separate the cells; then a cell wall forms in between the two membranes to officially separate them
Purposes of mitosis?
asexual reproduction, growth of an organism, repair of an organism
Result of mitosis
two nuclei that are identical to each other (number and kind of chromosomes)
mitotic spindle
an apparatus of microtubules that controls the movement of chromosomes during mitosis
Binary Fission
asexual reproduction in prokaryote cells
How does the nuclear membrane dissolving help cell division?
frees the DNA; allows spindles to attach to the centromere
Why are chromosomes seen as sister chromatids during prophase?
DNA has been replicated/duplicated before cell division; each sister chromatid has identical information
How often does bacteria divide?
every 20 minutes
How often does the stomach lining divide?
2 days
How often do skin cells divide?
20 days
What type of cells does mitosis result in?
somatic cells
