Mitosis Flashcards
What is mitosis used for?
Reproduction of single celled eukaryotes
Growth and development of multicellular organisms
Maintenance of multicellular organisms are
What is the only cell that does not preform mitotic cell division?
Germ cells
Ho do prokaryotes divide?
Binary fission.
What happens during binary fission?
Chromosomes attached to plasma membrane which grows between them to ensure they end up in different daughter cells
What is the mitotic cell division cell cycle?
G1 to S to G2 to M
What is S Phase?
DNA replicated forming a sister chromatids
What happens during M phase?
Chromosomes are divided evenly between two new cells
Why are G1 and G2 phased
Both are gap phases to help prepare the cell got the next step of the cell cycle
Make sure everything occurred correctly with the DNA
When and how does the cell grow in the mitotic cell cycle?
During gap phases by synthesizing proteins lipids and carbohydrates
What are the 5 stages that M phase can be divided into?
Prophase pro metaphase metaphase anaphase and telophase.
What happens in prophase?
Condense chromosomes. Centers ones start to move apart.
Site of micro tubule genisis
What happens in pro metaphase?
Nuclear envelope is taken apart and kinetochore occurs
What happens in metaphase?
Alrighnemt of chorizos ones on the center of the cell. Motor proteins on MT pulling in opposite direction to center chromosomes.
What happens in anaphase?
Sister chromatids separated and brought to opposite sides of the cell. The MTs shrink and proteins pull
What happens during telophase.
De Condensing of chromosomes. Reform nucleus and preform cytokinesis via contracting of microfilaments
What maintains the order of the cell cycle?
Cyclins
What do cycling do?
Ensure everything is going in the right order and serve the role as checkpoints and preventing progression of an error occurs
Where are mutations found that promote cancer?
Tumor suppressor a and oncogens.
What is normal function of a tumor suppressor?
Functions as a negative regulator of the cell cycle.
A brake.
What happens to a mutated tumor suppressor?
It divides in appropriately.
What is the normal function of an oncogen?
A positive regulator of the cell
A gas pedal
Describe tumor suppressor and oncogens role in cancer
Hundreds have been found in cancers, many cells must mutate before the onset of cancer. This requires multiple cell divisions and this occurs later in life.
What is the prevalence of cancer in the human body
We have 6 X 10^13 cells and 99.999999% of them will never become cancer
