Griffith Avery and Hershey and Chase

Who described the Transforming Principle - that diseased genes can be spread to healthy individuals

• Miescher

• Griffiths

• Watson & Crick

• Chargaff

Who explained the Transforming Principle using DNA as agent of the disease

• Levene

• Franklin & Wilkins

• Avery, MacLeod & McCarthy

• Hershey & Chase

• Griffith

Who showed that DNA and not proteins were the genetic material?

• Griffith

• Avery, MacLeod & McCarthy

• Franklin & Wilkins

• Hersey & Chase

Who discovered that dead pathogenic bacteria passed on their disease-causing properties to live, non-pathogenic bacteria?

• Levene

• Griffith

• Hershey & Chase

• Miescher

Avery built on Griffith’s work and concluded that DNA was the transformative agent that stored and transmitted genetic information between bacterial generations. But not all scientists were convinced. Hershey and Chase designed a confirming experiment using bacteriophages, which reproduce by injecting their genetic material into bacterial hosts. Hershey and Chase used unique radioactive tags: 35 S was used to tag the phage’s outer protein coat and 32 P was used to tag their DNA core. Then the phages were allowed to infect bacteria. When the bacteria were later tested, what type of radioactivity did Hershey and Chase find? And what did that finding mean?

• Hershey

  and Chase found only phosphorus-32 in the bacteria. The bacteriophage was injecting its

  DNA into the host. The DNA, not proteins, was the genetic information.

• Hershey

  and Chase found only phosphorus-35 in the bacteria. The bacteriophage was injecting its

  Protein into the host. The Protein, not DNA, was the genetic information.

• Hershey

  and Chase found only phosphorus-32 in the bacteria. The bacteriophage was injecting its

  Protein into the host. The Protein, not DNA, was the genetic information.

• Hershey

  and Chase found only phosphorus-35 in the bacteria. The bacteriophage was injecting its

  Protein into the host. The Protein, not DNA, was the genetic information.

Answer explanation

Hershey and Chase labeled the protein coats of bacteriophages with sulfur-35 and their

DNA with phosphorus-32. After allowing the bacteriophages to infect bacteria, Hershey

and Chase found only phosphorus-32 in the bacteria. This meant that the whole

bacteriophage was not entering the host bacteria. The bacteriophage was injecting its

DNA into the host. The DNA, not proteins, was the genetic information.

Tags

NGSS.HS-LS1-1

Who conducted the experiment that demonstrated the 'Transforming Principle' in bacteria?

• A) Hershey & Chase

• B) Avery, MacLeod & McCarty

• C) Griffith

• D) Watson & Crick

Which scientists used bacteriophages to show that DNA is the genetic material?

• A) Griffith

• B) Hershey & Chase

• C) Avery, MacLeod & McCarty

• D) Franklin & Wilkins

What was the main conclusion of Griffith's experiment with Streptococcus pneumoniae?

• A) DNA is the genetic material

• B) Proteins are the genetic material

• C) A 'transforming principle' can transfer genetic information

• D) RNA is the genetic material

In the Hershey-Chase experiment, what radioactive element was used to label DNA?

• A) Carbon-14

• B) Phosphorus-32

• C) Sulfur-35

• D) Nitrogen-15

What did Avery, MacLeod, and McCarty identify as the 'transforming principle'?

• A) RNA

• B) Protein

• C) DNA

• D) Lipids