bio unit 2 quiz 2 Flashcards
cell division
the process that allows a single cell to beocme an orgnism with trillons of cells
cell differentioaion
the process where newly formed cells become more specialized to perfom diffenrt funcions
cell specialization
cells take on specifc functions. accomplshed by differntial gene expression.
differntial gene expression.
the activation of differnt instructins within a given cell by chmical signals causing it to differenntiate. Same gene in all cellls. cell truing on and off.
gene expression and the environment
cells have contral over which gene are beig expressed so we say its a regulated process. cells can also respond to envronmental factors such as light and temperature.
purpose of cell division
happens in eukayotics
- for growth and developemnt
- for repair : replace dying cells, wear and tear, and regeneration of new cells.
cell cycle
the sequence of grwoth and division that occurs in cells. In cell cycle there is cell growth, DNA replication, Cell gowth, and then cell division.
phases of the cell cycle
interphase if first which consists of : G1 - growth , S phase - DNa synthesis and replication, G2 - more cell growht and cell geting ready to divide.
Then mitosis which consists of PMAT, which does nuclear division
then cytokinesis which is where the cytoplams divides
chromatin
the form of the DNA during interphase. Loose noodle like. Able to transcribe
Chromosome
the DNa when cell enters mitosis. The chromatn coils up to from chromoosmes. we have 46
interphase
befoer mitosis. Nuleus in visible. The DNA is in loose strands of chromatin.
G1
evryday cellular activity and the cell grows
G2
cell is prepared for mitoosis
g0
some cells can enter this. Is a resting pahses. Where the cell doe snot prepare to divide.
s phase
- DNa replication
this has to happend befreo cell division. Create new set of DNa identical to the fisrt.
DNa replication
DNa in chromosome is copied. Each chromosome has an identical copy. Each copy is called chromatid. they are refered to as siter chromatids. A centromere joins them together.
somatic cell
have a full set of chromosomes
Diploid
if a cell has a full set of chromosomes. symbol = 2n=#
pourpose of mitosis
the division of the nuclues, and its contents. 4 steps : PMAT
prophase
- nuclear envelope breaks down
- chromatin coild into the chromosome
- Centroles move to oppsosite ends, with spinde fibers in between.
metaphase
chromosmes duplicate with sister chromatids. They line up across the middel fo the cell.
Anaphase
the sister chromatids seprate inot indidual chromosomes. Are pulled to the oppposite ends of the cel.
telephase
the chromose is at eh oppise end of the cell. 2 new nuclear evelopes form and 2 nuclei appear. BUt not yet duplicated
cytokinesis
the cytoplam divided. Then 2 cells form. They are identical daughter cells with the same number of chromosomes.
cell plate
formed in cytokinesis. This is used to create the cell wall.
results of the cell cycle
2 genetically identical daughter cells with the same number of chromosomes. Same DNA.
cancer
disruption of the cell cycle. unontrolled cell division of abmnormal and damaged cells. The caner cel donts respond to regulatory signals. The cells dont listen to G0 or protein signals.
cycline
Cycline proteisn regulate the cell cycle.
external factors
directs cell to speed up or slow down. Can include growth factors. respond to the events outside of the cell
protoocgenes adn tumor suppressor genes
codes for porteins that help regulate cell growth and diviison. Tumer suppergenses stop the growth of abonral cell growht and division.
mutations in protoocgenes adn tumor suppressor genes
can crate diffent proteins that fail to regulate cell growh and function. can prevent cells from doing cell division. the most commn is p53.
g1 checkpoint
check to see if DNA is damaged
g2 checkpint
Check to see f DNA is replicated properly
M checkpint
spindel assembly checkpijt, check for the alignment of the shromosomes.
checkpoints
checkpoint see if anything is wrong during the cell cycle =. is worng then cell go throuhg repainr or the apoptosis they die.
some causes of cancer
uv-light, x -rays, smoking, chemicals, radiation expoture, and viral infection.
