Campbell Chapter 16 Online Test

1) In his transformation experiments, what did Griffith observe? 

• Mutant mice were resistant to bacterial infections.
• 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 strain

How do we describe transformation in bacteria? 

• the creation of a strand of DNA from an RNA molecule 
• the creation of a strand of RNA from a DNA molecule 
• the infection of cells by a phage DNA molecule
•  assimilation of external DNA into a cell

After mixing a heat-killed, phosphorescent strain of bacteria with a living nonphosphorescent strain, you discover that some of the living cells are now phosphorescent. Which observations would provide the best evidence that the ability to fluoresce is a heritable trait? 

• DNA passed from the heat-killed strain to the living strain. 
• Protein passed from the heat-killed strain to the living strain. 
• The phosphorescence in the living strain is especially bright.
•  Descendants of the living cells are also phosphorescent. 

After mixing a heat-killed, phosphorescent strain of bacteria with a living nonphosphorescent strain, you discover that some of the living cells are now phosphorescent. Which observations would provide the best evidence that the ability to fluoresce is a heritable trait? 

• DNA passed from the heat-killed strain to the living strain. 
• Protein passed from the heat-killed strain to the living strain. 
• The phosphorescence in the living strain is especially bright.
•  Descendants of the living cells are also phosphorescent. 

In trying to determine whether DNA or protein is the genetic material, Hershey and Chase made use of which of the following facts? 

•  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 following discovery? 
In DNA from any species, the amount of adenine equals the amount of thymine, and the amount of guanine equals the amount of cytosine

• Frederick Griffith 
• Alfred Hershey and Martha Chase 
• Oswald Avery, Maclyn McCarty, and Colin MacLeod 
•  Erwin Chargaff 

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%
• 31%
• 42%

Which of the following can be determined directly from X-ray diffraction photographs of crystallized DNA? 

• the diameter of the helix 
• the rate of replication 
• the sequence of nucleotides 
• the bond angles of the subunits 

It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information in which of the following? 

• sequence of bases 
• phosphate-sugar backbones 
• complementary pairing of bases 
• side groups of nitrogenous bases 

In an analysis of the nucleotide composition of DNA, which of the following will be found? 

• A = C 
•  A = G and C = T 
• A + C = G + T 
• G + C = T + A