AP Biology Unit 6 DNA Experiments

Griffith investigated R and S strains with mice. What did he conclude about the S strain and the R strain in the trial with heat-killed S strain and living R strain?

• The mouse lived as the R strain provided protection from the nonliving S strain

• The mouse died as the R strain did not provide protection from the nonliving S strain

• The mouse lived as the R strain was not affected by a transforming agent released from the nonliving S strain

• The mouse died as the R strain was affected by a transforming agent released from the nonliving S strain

What was the difference between the R and S strains in the Griffith experiment?

• R strain was pathogenic while S strain was not pathogenic

• R strain was not pathogenic while S strain was pathogenic

What technology did Rosalind Franklin use to produce the image of the DNA molecule used by Watson & Crick?

• X-ray crystallography

• Light microscope

• Electron microscope

• NMR

What feature did Hershey and Chase use to differentiate between protein and nucleic acid in their experiment?

• Proteins have phosphorus and nucleic acids have sulfur

• Proteins have sulfur and nucleic acids have phosphorus

• Proteins are single stranded and nucleic acids are double stranded

• Proteins are double stranded and nucleic acids are single stranded

Based on the conservative model, what are the predicted results from two rounds of replications in the Meselson-Stahl experiment where the initial strands are ¹⁵N and the new strands are ¹⁴N?

• The first round involves a hybrid (¹⁴N-¹⁵N) band, the second round involves a light (¹⁴N) band and a hybrid (¹⁴N-¹⁵N) band

• The first round involves a hybrid (¹⁴N-¹⁵N) band, the second round involves a hybrid (¹⁴N-¹⁵N) band

• The first round involves a heavy (¹⁵N) band and a light (¹⁴N) band, the second round involves a hybrid (¹⁴N-¹⁵N) band

• The first round involves a heavy (¹⁵N) band and a light (¹⁴N) band, the second round involves a heavy (¹⁵N) band and a light (¹⁴N) band

Based on the semiconservative model, what are the predicted results from two rounds of replications in the Meselson-Stahl experiment where the initial strands are ¹⁵N and the new strands are ¹⁴N?

• The first round involves a hybrid (¹⁴N-¹⁵N) band, the second round involves a light (¹⁴N) band and a hybrid (¹⁴N-¹⁵N) band

• The first round involves a hybrid (¹⁴N-¹⁵N) band, the second round involves a hybrid (¹⁴N-¹⁵N) band

• The first round involves a heavy (¹⁵N) band and a light (¹⁴N) band, the second round involves a hybrid (¹⁴N-¹⁵N) band

• The first round involves a heavy (¹⁵N) band and a light (¹⁴N) band, the second round involves a heavy (¹⁵N) band and a light (¹⁴N) band

Based on the dispersive model, what are the predicted results from two rounds of replications in the Meselson-Stahl experiment where the initial strands are ¹⁵N and the new strands are ¹⁴N?

• The first round involves a hybrid (¹⁴N-¹⁵N) band, the second round involves a light (¹⁴N) band and a hybrid (¹⁴N-¹⁵N) band

• The first round involves a hybrid (¹⁴N-¹⁵N) band, the second round involves a hybrid (¹⁴N-¹⁵N) band

• The first round involves a heavy (¹⁵N) band and a light (¹⁴N) band, the second round involves a hybrid (¹⁴N-¹⁵N) band

• The first round involves a heavy (¹⁵N) band and a light (¹⁴N) band, the second round involves a heavy (¹⁵N) band and a light (¹⁴N) band

Which of the following did Watson & Crick determine from the image provided by Rosalind Franklin?

• Approximate width of the DNA molecule

• Length of one turn of the DNA molecule

• Number of nucleotides in the DNA molecule

• Nitrogenous bases order in the DNA molecule

What information did Chargaff provide to Watson & Crick to aid in their understanding of base pairing?

• Adenine pairs with thymine and guanine pairs with cytosine

• Adenine pairs with guanine and thymine pairs with cytosine

• Adenine pairs with cytosine and guanine pairs with thymine

• Adenine pairs with adenine and thymine pairs with thymine

Which scientist(s) conclusively proved that DNA was the genetic material for organisms?

• Chargaff

• Watson & Crick (+ Rosalind Franklin)

• Griffith

• Hershey & Chase

• Meselson & Stahl