In his transformation experiments, what phenomenon did Griffith observe?

• Infecting mice with nonpathogenic strains of bacteria makes them resistant to pathogenic strains.

• Mixing a heat-killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living cells into the pathogenic form.

• Mice infected with a pathogenic strain of bacteria can spread the infection to other mice.

• Mixing a heat-killed nonpathogenic strain of bacteria with a living pathogenic strain makes the pathogenic strain nonpathogenic.

Which of the following statements describes the process of transformation in bacteria?

• A strand of RNA is created from a DNA molecule.

• A strand of DNA is created from an RNA molecule.

• Bacterial cells are infected by a phage DNA molecule.

• External DNA is taken into a cell, becoming part of the cell's genome.

A heat-killed, phosphorescent (light-emitting) strain of bacteria is mixed with a living, non-phosphorescent strain. Further observations of the mixture show that some of the living cells are now phosphorescent. Which of the following observations would provide the best evidence that the ability to phosphoresce is a heritable trait?

• Evidence that DNA was passed from the heat-killed strain to the living strain

• Especially bright phosphorescence in the living strain

• Evidence that protein passed from the heat-killed strain to the living strain

• Phosphorescence in descendants of the living cells

Tags

NGSS.HS-LS3-1

NGSS.HS-LS3-2

Which of the following facts did Hershey and Chase make use of in trying to determine whether DNA or protein is the genetic material?

• DNA contains purines, whereas protein includes pyrimidines.

• DNA contains nitrogen, whereas protein does not.

• DNA contains phosphorus, whereas protein does not.

• DNA contains sulfur, whereas protein does not.

Which of the following investigators was (were) responsible for the discovery that in DNA from any species, the amount of adenine equals the amount of thymine, and the amount of guanine equals the amount of cytosine?

• Oswald Avery, Maclyn McCarty, and Colin MacLeod

• Erwin Chargaff

• Matthew Meselson and Franklin Stahl

• Alfred Hershey and Martha Chase

Cytosine makes up 42% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this sample will be thymine?

• 58%

• 8%

• 42%

• 16%

Thymine makes up 28% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this sample will be guanine?

• 8%

• 72%

• 16%

• 22%

It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information. Which of the following characteristics of DNA is responsible for this?

• phosphate-sugar backbones

• complementary pairing of bases

• sequence of bases

• side groups of nitrogenous bases

Tags

NGSS.HS-LS3-1

In an analysis of the nucleotide composition of a molecule of DNA, which of the following combinations of base pairs will be found?

Hershey and Chase set out to determine what molecule served as the unit of inheritance. They completed a series of experiments in which *E. coli* was infected by a T2 virus. Which molecular component of the T2 virus actually ended up inside the cell?

• RNA

• ribosome

• DNA

• protein