Bio / Biochem: Cellular Reproduction Flashcards
How many stage does the cell cycle have?
5
Autosomal cells are ___ (2n) while germ cells are ____ (n).
diploid (2n) ; haploid (n)
G1, S, and G2 are collectively known as what?
Interphase
What is the longest part of the cell cycle?
Interphase
Cells that don’t divide (muscle / nerve) spend all of their time in an offshoot of G1, called what?
G0 (G- naught) = continued growth
What happens in G1 (Presynthetic Gap)?
- cells grow & create organelles to make energy and produce proteins ; increase in size of cell ; restriction point to pass onto S phase
What happens in S (Synthesis) Phase?
DNA replicates, after which the chromosomes are in their familiar X forms made of 2 identical sister chromatids
What happens in G2 (Postsynthetic Gap)?
checkpoints:
- check the cell has enough organelles and cytoplasm to divide
- check for DNA replication errors
What happens in the M (Mitotic) Phase?
division, followed by another technical phase (cytokinesis is technically it’s own phase)
What happens during the G1/S checkpoint?
checks if DNA is good for synthesis phase ; if there is damage the cell cycle arrests until it is repaired
What happens during the G2/M checkpoint?
checks if the cell is large enough (has enough organelles and cytoplasm) to divide into 2 daughter cells ; have organelles all replicated?
Which is not a major player protein in cell division? p53, cyclins & their kinases, and transcription factors.
All of them are majorly important to the cell cycle’s progression.
What disease does the cell cycle become deranged in, so that cells with damaged DNA are allowed to pass checkpoints and continue replicating?
Cancer
How does a p53 mutation lead to cancer?
if p53 is mutated, damaged DNA is not tagged for repair so the cell cycle doesn’t arrest to repair it ; mutations accumulate and the cancer cells start to divide continuously ; rapid division leads to tumors
What is metastasis?
when cancerous cells reach other tissues from the ones they originate in
Mitosis occurs in what kind of cells?
somatic cells only!! never germ cells
What are the 4 phases of mitosis?
Prophase, Metaphase, Anaphase, Telophase
What is the final phase of the cell cycle?
Mitosis
What is inside the centrosome? (at the end of interphase before mitosis begins?)
Centrioles
What occurs in prophase of mitosis?
chromatin condenses into X’s (wound around histones) ; the pair of centrioles in the centrosome separate and start moving towards opposite ends of the cell ; the centrioles start making spindle fibers
What does a cell’s DNA look like at the end of interphase?
uncondensed chromatin
