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Programmed Variation
Phase Variation
Random Variation
Misc.
100
Is programmed variation intentional or random?
Intentional
100
What is phase variation?
It's the method for changing the phenotype.
100
What is random variation?
Random variation is when antigenic variation takes place due to random factors.
100
How do cells benefit from antigenic variation?
They are able to evade the immune system and not die for longer.
200
What are the mechanisms behind programmed variation?
Conversion, Homologous recombination, and Transcription regulation.
200
What evidence is there for phase variation?
Color variation experiment (different proteins caused the cell to display different dyes) and observation.
200
How does antigenic drift happen?
That happens when small mutations are created due to the RDRP messing up.
200
What's dangerous about antigenic variation for humans?
It allows for the cell to live longer and release exotoxins as well as wearing down the immune system.
300
When does programmed variation happen?
There are two times: The first is during homologous recombination during crossing over and the other is when the DNA goes through a double stranded break (the reason for this break happening is still unknown). It might be worth noting that another mechanism for this, transcription regulation, can still happen even when the other two factors are't.
300
What's the difference between Phase variation and antigenic variation?
Basically, phase variation focuses on turning on/off the phenotypes (the actual antigens on the cell) while antigenic variation changes the genotype.
300
What's antigenic drift?
It's when multiple kinds of the same virus end up in the same organism and reproduce from the same cells. It creates a mixture of genes in new virus cells.
300
What environmental factors trigger antigenic variation?
We really don't know for sure.