Living Environment – Lesson 52
Danta/Meeker
Name____________________________
Avery and Hershey-Chase Experiments
Do Now: What was Griffith’s experiment and what did it show?
Explore: Look at the slide of the results of the Avery Experiment and answer the following
What question was Avery trying to test?
Why didn’t Avery trust Griffith?
What is a possible conclusion of the Avery Experiment?
What did the experiment show about bacteria?
Does this experiment show anything about DNA? Explain
What was Avery’s controls? Explain
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Living Environment – Lesson 52
Danta/Meeker
Oswald Avery (1877-1955)

Spent most of his career at Rockefeller University in ____________________________

Said to be one of the most deserving scientists not to win ________________________
o Was nominated many times
Between Griffith and Avery

Scientists thought __________________________ carried genetic information

Griffith’s experiments were __________________________ in the 1930s

Scientists still had no idea ____________________ was the hereditary material
Transformation: The genetic change of a cell from the uptake of _______________ from the
surroundings
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In Griffith experiment ____________________ was transformed into R Pneumococcus

One of 3 ways for bacteria ___________________________
What is the central dogma, and why do we know that DNA is the hereditary info?
What type of molecules usually ends in “-ase”? _______________________
Avery experiment (Avery-MacLeod-McCarty experiment)

Expanded on ________________________

Got rid of ______________________ and saw what worked

If _____________ was destroyed, ____________________ did not work
Hershey Chase: Look at the experimental data and answer the questions.
What question were Hershey-Chase trying to test?
What is a possible conclusion of the Hershey-Chase Experiment?
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Living Environment – Lesson 52
Danta/Meeker
What do you think radiolabeling means?
Does this experiment show anything about DNA? Explain
What would be good controls for this experiment? Explain
After Avery experiment

Avery experiment gave evidence DNA ____________________________________
o Most scientists were still not ___________________________
o Avery experiment only showed ___________________________________

Scientists still thought ___________________ had the info
Differences between protein and DNA

Proteins have __________________
o For a special __________________

DNA has _____________________
Radiolabeling: Tagging something with a ______________________ substance

Can make a specific _____________________ radioactive so that it glows/changes color

Usually use color ______________ or ______________
Hershey-Chase background

Scientists already knew viruses had __________________ and _____________
o Also knew viruses could transfer _______________________ to bacteria
o Bacteriophage: Virus that infects ______________________
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Living Environment – Lesson 52
Danta/Meeker
What is the question of the Hershey-Chase experiment?
Hershey-Chase Experiment
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Labeled protein coat of ________________________________
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Labeled DNA inside of bacteriophage ____________________
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Allowed virus to infect _____________________
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Found that inside cell _________________________

Red stayed with the ___________________
How they tested their results
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After infection put _____________ and __________________ in solution
o Found chopped up ________________ but no _______________

Means all DNA went _____________________
After Hershey-Chase

They never said __________________________________
o Only that it was _______________________

Helped convince Watson and Crick ___________________________
What was Hershey-Chase’s results in your own words?
What was Hershey-Chase’s conclusion?
What carries hereditary information? ____________________
What is the central dogma? __________________________________________________
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