Flashcards in The Genetic Material Deck (12):
Why must genetic material be capable of replication with sufficient fidelity?
So that organisms can pass their characteristics on to their offspring.
Why must genetic material be capable of undergoing some change?
Otherwise evolution could not have occured
Why must genetic information be capable of encoding vast amounts of information?
In order to programme the complexity of living organisms.
Who first observed genetic transformations?
Griffiths in 1928
What was Griffiths study?
Two types of bacteria: TypeIIR (nonvirulent) and TypeIIIS (virulent). TypeIIR does not kill while typeIIIS does. Dead typeIIIS + living typeIIR kills mouse and typeIIIS can be detected
What do the S and R stand for?
Rough and smooth
Who showed that the transforming principle was DNA?
Avery et al.
How did Avery show that the transforming principle was DNA?
Treated a mix of DNA and RNA with an RNase so only DNA remained. Added this to R bacteria and grown on a plate produces S bacteria. If treated with a DNase there were no S transformations.
How did Hershey and Chase (1952) prove Avery et al.'s conclusion?
Used a bacteriophage T2, infects E.colli gown in 32P, progeny phages have 32P-labelled DNA. Repeat with T2 and 35S-containing medium. Allow both phages to bind to new E.coli the briefly blend to remove phage ghosts. RAdioactivity recovered in host and passed on to phage progeny from 32P DNA.
Why are bacteriophage's useful for genetic studies?
Large numbers can be generated.
What did the X pattern in the X-ray crystallography of Franklin and Wilkins produce?