4 common features of all cells are structure, function, reproduction, and the cell cycle
The purposes of cell division are organism growth and development, damage repair of tissues, and reproduction to produce more cells
mitosis is the division of the nuclei
cytokinesis is the division of the cytoplasm
unlike animal cells which have cell membranes, plant cells possess cell walls
cells that frequently divide include skin cells, intestinal cells, and cheek cells
a type of cell that infrequently divides are liver cells
a type of cell that never divides are nerve cells
If the cell cycle is not regulated, it could potentially lead to the development of cancer cells
The stages of the cell cycle are: G1, S, G2, and M.
G1 phase is the growth phase of the cell cycle where the cell grows and prepares for DNA replication.
S is the stage of the cell cycle where the DNA replication occurs.
G2 is where the cell rapidly grows to prepare for cell division
The M-phase is mitosis.
Interphase is composed of the G1, S, and G2 phase.
Gap phases: preparation of the cell for mitosis
Label this
A) interphase
B) g1
C) s
D) g2
E) m
Checkpoints during the cell cycle occur at the G1 phase (where it can go to the G0 phase), G2 phase (where the MPF complex occurs), and the m-phase (where the cells are stopped from dividing during mitosis).
Mitosis-promoting factors or MPFs are at maximum levels during mitosis and the levels are correlated with cyclin levels.
cyclin is a regulatory protein which activates kinase via phosphorylation. When cyclin is added to CDK forms MPF.
The platelet derived growth factor (PDGF) is a growth factor that stimulates the cell division to result in the production of tissue to repair damage. The fibroblasts have a receptor to bind tyrosine kinases present in PDGF.
Prophase = chromosomes appear with sister chromatids. The spindle apparatus forms (contains microtubules).
Prometaphase = nuclear envelope breaks down. The microtubules attach to chromosomes at the centromere (kinetochores)
Metaphase = sister chromatids migrate to the middle of the cell. Spindle apparatus is complete. Chromosomes line up.
Anaphase = chromatids (chromosomes) are pulled along by kinetochore microtubules
Telophase = spindle apparatus breaks down. Nuclear envelope forms around chromosomes. Chromosomes de-condense.
Cytokinesis = division of cytoplasm and formation of cell membrane around two new cells
Stem cells can differentiate into different cells and are normally derived from embryonic tissues, umbilical cord, or amniotic fluid.
Struggles when differentiating stem cells into other cell types include: the cells being rejected by the immune system, or the stem cells growing irregularly or differentiating into undesired cell types