Biology Chapter 16 Questions

In his transformation experiments, what phenomenon did Griffith observe?

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

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

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

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

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

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

• A strand of RNA is created from a DNA 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, nonphosphorescent 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

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

• Especially bright phosphorescence in 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 sulfur, whereas protein does not.

• DNA contains phosphorus, whereas protein does not.

• DNA contains nitrogen, whereas protein does not.

• DNA contains purines, whereas protein includes pyrimidines.

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?

• Alfred Hershey and Martha Chase

• Oswald Avery, Maclyn McCarty, and Colin MacLeod

• Erwin Chargaff

• Matthew Meselson and Franklin Stahl

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?

• 8%

• 16%

• 42%

• 58%

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%

• 16%

• 22%

• 72%

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?

• sequence of bases

• phosphate-sugar backbones

• complementary pairing of bases

• side groups of nitrogenous bases

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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?

• A = C

• A = G and C = T

• A + C = G + T

• G + C = T + A

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NGSS.HS-LS1-1

For a science fair project, two students decided to repeat the Hershey and Chase experiment, with modifications. They decided to radioactively label the nitrogen of the DNA, rather than the phosphate. They reasoned that each nucleotide has only one phosphate and two to five nitrogen atoms. Thus, labeling the nitrogen atoms would provide a stronger signal than labeling the phosphates. Why won't this experiment work?

• There is no radioactive isotope of nitrogen.

• Radioactive nitrogen has a half-life of 100,000 years, and the material would be too dangerous for too long.

• Although there are more nitrogens in a nucleotide, labeled phosphates actually have 16 extra neutrons; therefore, they are more radioactive.

• Amino acids (and thus proteins) also have nitrogen atoms; thus, the radioactivity would not distinguish between DNA and proteins.