Avery, hershey/chase experiments using bozeman biology YT

1. 3 Major experiments in confirming DNA is the genetic material
http://www.youtube.com/watch?v=qoERVSWKmGk (Bozeman Biology History of DNA)
Frederick Griffiths
Frederick Griffiths looked at ___________________, which has 2
strains________________ (virulent) and ____________________ (non-virulent).
The mouse ____________ when Smooth (S) live bacteria where injected, unlike when live
___________ (R) were injected. Which of these experiments was the
control?____________________ When S bacteria were heat killed the
mouse____________________, since the bacteria were dead they could not infect the
mouse. Griffiths then mixed heat killed _________________ strain and live Rough (R).
He then injected the mouse which then died. This, Griffith believed was from a
_______________________ moving from the dead Smooth (virulent) to the living
_____________ (non-virulent)

2. Avery:
What did Avery figure out?
What 3 molecules did his team isolate that were candidates for the genetic material?
Avery‟s team isolated 3 main molecules from heat killed smooth strain. Avery then added
_________________ separately to digest _______, _______, or ______________.
(One enzyme per biological molecule). These digested mixtures were added to Rough live
bacteria and then injected into mice. Avery then observed whether or not they killed the
mice. Avery determined that when ____________ was digested with DNAse (meaning it
was no longer „transforming‟ the _____________ strain) the mice lived. If the isolated
DNA was added without being destroyed by enzymes the mouse died. This meant that Avery
determined that ___________ was the genetic material. Why did scientists think
otherwise?
Image taken from textbook:

3. Hershey and Chase:
Above we learned that Fredrick Griffith discovered a __________________. By the late
1940‟s, scientists knew that eukaryotic chromosomes consisted of two substances: DNA and
protein. There are twenty amino acids and only four bases that make up DNA, so scientists
at the time thought that DNA was too simple to account for all the traits in organisms. In
1952 Alfred Hershey and Martha Chase performed one of the most convincing experiments,
that DNA not protein is the genetic material. They used bacteriophages
(_____________________) (called phages for short). Bacteriophages are actually
____________. Viruses do not have their own machinery to replicate, so they hijack cells
to create more copies of themselves. Hershey and Chase used 2 different
__________________, Sulphur, which was “dyed” red and Phosphorus “dyed”
________. Sulphur was important because it is found in ___________________ but
not_______________. Phosphorus is found in DNA but not in _______________.
The only one that was found to “transfer” was the green dye finally proving that
___________was the „transforming‟ material and was „transferring the genetic code.

4. http://en.wikipedia.org/wiki/Hershey%E2%80%93Chase_experiment