The cell cycle Flashcards
Interphase
definition and phases
cell growth and copying of chromosomes
- its about 90% of the cell cycle
- G1 : metabolic activity & growth
- S : metabolic activity growth and DNA synthesis
- G2 : metabolic activity growth and preparation for cell division
Miotic (M) phase
phases
Mitosis - distribution of chromosomes into two daughter nuclei
Cytokinesis - division of cytoplasm, producing 2 daughter cells
The miotic spindle
What are centrosomes
in animal cells its the assebly of spindle microtubule and replictae during the interphase making 2 centrosomes
The miotic spindle
kinetochore
- a protein complex associated with centrosomes
- some microtubles attach to kinetochores during prometaphase
The miotic spindle
anaphase
- cohesion are cleaved
- sister chromatid seperate and move along the kinetochore
The miotic spindle
metaphase plate
at metaphase the chromosomes are line up at this step
The miotic spindlex
telophase and cytokinesis
cytokinesis - begins during anaphase or telophase and spindle eventually disassemble and occurs by a process called cleavage
telophase and cytokinesis
cleavage and cleavage furrow
slide 20
Cleave furrow - found in animal cells in cytokinesis which pinches the cytoplasm to two lobes that then separates into 2 cells
telophase and cytokinesis
cell plate
found in plant cells and forms during cytokinesis
what is the cell cycle control system
define checkpoints
G0 - phase where the cell might leave the cycle due to not passing the checkpoint in G1
G1 - checks to see if cell has enough nutrients and if it has growth factors to decide into 2 cells
G2 - checks to see if the cell has any damage or if the DNA was completely duplicated in the S phase
M - known as spindle checkpoint makes sure that each sister chromatid is properly attached to the spindle microtubules
signal checkpoints
internal and external signal at checkpoint
examples
checkpoints in G1, G2, G0 and M
The cell cycle clock
cyclins
cyclins
The cell cycle clock
cyclin - dependent kinases
