Theme 2D Iheritance Of Dna Flashcards
What is the cell cycle
The process, where one cell grows and divides into two daughter cells
What is the first step of the cell cycle
G1 (gap phase) where proteins, RNA, metabolites and anything other than DNA is synthesized
What is the second step of the cell cycle
S phase Where DNA replication occurs
What is the third phase of cell cycle
G2 phase
What is the 4 step of cell cycle
M-phase where
mitosis: nuclear division (seperation of chromosome)
Cytokinesis: cell division (separation of cell into two daughter cells)
Occurs
What is the last phase of the cel cycle
G0: resting phase or quienscence
(When cells stop dividing, no more telomeres)
What phase of the cel cycle are most adult human cells in
G0 permanently (muscle or nerve cells)
Or semipermanently (liver cells reenter g1 during injury)
What is cyclin dependent kinase
Enzyme that adds phosphate to protien substrate
Need to be activated in order to progress the cell cycle
Is bound to a regulatory cyclin subunit in each phase of cell cycle
What are checkpoints during the cell cycle
They delay the cell cycle to allow completion of the events in each phase before moving onto the next phase
What is the DNA damage checkpoint
Where does it occur
Makes sure dna is okay for replication
Happens between G1 and S phase
What is the DNA replication checkpoint
Where does it happen
Checks if DNA is fully replicated before mitosis
Happens between G2 and M phase
What is the mitotic spindle checkpoint
Where does it occur
Check if chromosome are aligned properly in metaphase
Happens before anaphase
How is cancer caused in relation to cell division?
Caused by uncontrolled cell division, and altered expression of multiple genes due to mutations
What mutated genes are in cancers
Onco genes and tumour suppressor genes
What do ONCOGENES do
They are positive regulators of the cell cycle (gain of function) so they amplify the cell cycle turns, and they amplify the genes through cyclin D/E
Insensitive to inhibition
What are tumour suppressor genes?
Negative regulators of the cell cycle (loss of function) including checkpoint jeans P 53 and RB. This causes no cell cycle stops, because the checkpoint genes aren’t functioning.
What does n mean?
Haploid number of unique chromosomes
What does 2n mean?
Diploid number of chromosome
What are homologous chromosomes
Maternal and paternal pair of. Chromosomes.
One from mom one from dad
Review slides 6 7 8 9
Describe the cell cycle in prokaryotes
Replication starts at the origin, where the chromosome is attached to the cell membrane
Then the cell elongates so the replicated chromosomes can separate
The plasma membrane of the cell undergoes inward growth and creates a new cell wall.
Each chromosome goes into their own separated cell. This makes two daughter cells
What is pre meiotic replication
Occurs in germ cells
Pre meiotic replication duplicates 4 chromatids to make 4 chromosome with 2 chromatids per chromosome
At the start of prophase 1, the chromosomes (homologous pairs) condense
Then synapsis occurs where non sister chromatids from each homologous pair, are attached together by the synaptonemal complex
What is happening at the start of prophase 1 in meiosis
At the start of prophase 1, the chromosomes (homologous pairs) condense
What is happening during synapsis in meiosis 1
Then synapsis occurs where each homologous pair, are attached together by the synaptonemal complex
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