Question 1

Which of the following does NOT describe the secondary structure of DNA as proposed by Watson and Crick?

Accepted Answer

A)  The two strands of the double helix are stabilized by hydrogen-bonding between A and T and between G and C. 
B)  The two strands of the double helix run in opposite directions. 
C)  The distance between the 1' carbons of the deoxyribose units is the same between the A-T and the G-C base pair. 
D)  The phosphate deoxyribose backbones of the helix are on the outside. 
E)  The base pairs are stacked on one other with their planes at 180o to the helix axis. 
A)  The two strands of the double helix are stabilized by hydrogen-bonding between A and T and between G and C. 
B)  The two strands of the double helix run in opposite directions. 
C)  The distance between the 1' carbons of the deoxyribose units is the same between the A-T and the G-C base pair. 
D)  The phosphate deoxyribose backbones of the helix are on the outside. 
E)  The base pairs are stacked on one other with their planes at 180o to the helix axis. E

Question 2

Viral genomes cannot be used as vectors for making recombinant DNA molecules.

Accepted Answer

A) True 
 B)False  False

Question 3

Dideoxynucleotide sequence analysis is a template-directed method that makes use of chain terminators that stop DNA synthesis because they lack a 2'OH group.

Accepted Answer

A) True 
 B)False  False

Question 4

Which statement is CORRECT?

Accepted Answer

A)  Both phosphodiester and glycosidic bonds in RNA and DNA are hydrolyzed in acid solution. 
B)  Both RNA and DNA are hydrolyzed in mild alkaline solution. 
C)  DNA is more unstable when dehydrated than when in solution 
D)  RNA is not hydrolyzed in mild alkaline solution. 
E)  Both A and B 
A)  Both phosphodiester and glycosidic bonds in RNA and DNA are hydrolyzed in acid solution. 
B)  Both RNA and DNA are hydrolyzed in mild alkaline solution. 
C)  DNA is more unstable when dehydrated than when in solution 
D)  RNA is not hydrolyzed in mild alkaline solution. 
E)  Both A and B

Question 5

The melting temperature of DNA ________ with increasing G plus C content.

Accepted Answer

The answer of The melting temperature of DNA ________ with...

Question 6

The difference between a nucleoside and a nucleotide is:

Accepted Answer

A)  the presence of uracil. 
B)  a phosphate group. 
C)  a phosphodiester bond. 
D)  a 2' -H group. 
E)  methylated cytosine. 
A)  the presence of uracil. 
B)  a phosphate group. 
C)  a phosphodiester bond. 
D)  a 2' -H group. 
E)  methylated cytosine.

Question 7

Restriction endonucleases are useful in gene cloning because:

Accepted Answer

A)  they can cut DNA at specific sequences. 
B)  they can join DNA molecules that have been cut at specific sequences. 
C)  they all make cohesive ends when they cut DNA. 
D)  they all make 5' phosphate extensions and recessed 3' OH groups that can be rejoined by DNA ligase. 
E)  they can both cut and rejoin DNA molecules. 
A)  they can cut DNA at specific sequences. 
B)  they can join DNA molecules that have been cut at specific sequences. 
C)  they all make cohesive ends when they cut DNA. 
D)  they all make 5' phosphate extensions and recessed 3' OH groups that can be rejoined by DNA ligase. 
E)  they can both cut and rejoin DNA molecules.

Question 8

The nucleotide sequence of a polynucleotide chain is called the ________ structure.

Accepted Answer

The answer of The nucleotide sequence of a polynucleotide chain...

Question 9

Nucleic acids absorb light strongly in the ultraviolet region of the spectrum because they have ________ double-bond systems.

Accepted Answer

The answer of Nucleic acids absorb light strongly in the...

Question 10

DNA in vivo is normally ________ supercoiled.

Accepted Answer

The answer of DNA in vivo is normally ________ supercoiled....

Question 11

Which of the following is a feature of X-diffraction?

Accepted Answer

A)  Radiation passing through a structure will be scattered only if the structure contains repeating units. 
B)  Scattered radiation from repeating units in a structure will be weakened by interference. 
C)  Scattered radiation from repeating units in a structure will be strengthened by interference. 
D)  Short spacings in repeating structures will result in short spacings in diffraction patterns. 
E)  The wavelength of radiation used to generate diffraction patterns must be slightly longer than the spacings between the repeating units of the structure. 
A)  Radiation passing through a structure will be scattered only if the structure contains repeating units. 
B)  Scattered radiation from repeating units in a structure will be weakened by interference. 
C)  Scattered radiation from repeating units in a structure will be strengthened by interference. 
D)  Short spacings in repeating structures will result in short spacings in diffraction patterns. 
E)  The wavelength of radiation used to generate diffraction patterns must be slightly longer than the spacings between the repeating units of the structure.

Question 12

An important observation that assisted in the elucidation of the secondary structure of DNA was that the mole percent adenine was almost always the same as the mole percent of thymine.

Accepted Answer

A) True 
 B)False

Question 13

Calculate the linking number in vivo for a plasmid that is 4200 bp in size if there is normally 1 negative supercoil in every 20 base pairs of a circular DNA. Assume there are 10.5 bp per turn of the double helix.

Accepted Answer

The answer of Calculate the linking number in vivo for...

Question 14

Expression of genetic information involves first ________ then ________.

Accepted Answer

transcript

Question 15

The mode of replication of DNA is BEST described as ________.

Accepted Answer

The answer of The mode of replication of DNA is...

Question 16

Single-stranded RNA molecules can have extensive regions of intramolecular base pairing leading to defined secondary and tertiary structure.

Accepted Answer

A) True 
 B)False

Question 17

Calculate the superhelix density of a circular DNA molecule with 210 base pairs and two negative supercoils, assuming that there are 10.5 bp per turn of the double helix.

Accepted Answer

The answer of Calculate the superhelix density of a circular...

Question 18

Which of the following statements about nucleic acid secondary structure is FALSE?

Accepted Answer

A)  The width of the major and minor grooves is more equal in the A-from of DNA than in the B-form. 
B)  Triple helices and G-quadruplexes can form at specific sequences in DNA. 
C)  DNA can form cruciform structures at palindromic sequences. 
D)  The A-form of DNA exists at high humidity, whereas the B-form exists at low humidity. 
E)  Some nucleic acids can form a zig-zag structure or Z form. 
A)  The width of the major and minor grooves is more equal in the A-from of DNA than in the B-form. 
B)  Triple helices and G-quadruplexes can form at specific sequences in DNA. 
C)  DNA can form cruciform structures at palindromic sequences. 
D)  The A-form of DNA exists at high humidity, whereas the B-form exists at low humidity. 
E)  Some nucleic acids can form a zig-zag structure or Z form.

Question 19

Supercoiled DNA has a lower mobility than relaxed DNA with the same number of base pairs when subjected to gel electrophoresis.

Accepted Answer

A) True 
 B)False

Question 20

Nucleotides are all weak acids.

Accepted Answer

A) True 
 B)False

Exam 4: Nucleic Acids

Which of the following does NOT describe the secondary structure of DNA as proposed by Watson and Crick?

Viral genomes cannot be used as vectors for making recombinant DNA molecules.

Dideoxynucleotide sequence analysis is a template-directed method that makes use of chain terminators that stop DNA synthesis because they lack a 2'OH group.

Which statement is CORRECT?

The melting temperature of DNA ________ with increasing G plus C content.

The difference between a nucleoside and a nucleotide is:

Restriction endonucleases are useful in gene cloning because:

The nucleotide sequence of a polynucleotide chain is called the ________ structure.

Nucleic acids absorb light strongly in the ultraviolet region of the spectrum because they have ________ double-bond systems.

DNA in vivo is normally ________ supercoiled.

Which of the following is a feature of X-diffraction?

An important observation that assisted in the elucidation of the secondary structure of DNA was that the mole percent adenine was almost always the same as the mole percent of thymine.

Calculate the linking number in vivo for a plasmid that is 4200 bp in size if there is normally 1 negative supercoil in every 20 base pairs of a circular DNA. Assume there are 10.5 bp per turn of the double helix.

Expression of genetic information involves first ________ then ________.

The mode of replication of DNA is BEST described as ________.

Single-stranded RNA molecules can have extensive regions of intramolecular base pairing leading to defined secondary and tertiary structure.

Calculate the superhelix density of a circular DNA molecule with 210 base pairs and two negative supercoils, assuming that there are 10.5 bp per turn of the double helix.

Which of the following statements about nucleic acid secondary structure is FALSE?

Supercoiled DNA has a lower mobility than relaxed DNA with the same number of base pairs when subjected to gel electrophoresis.

Nucleotides are all weak acids.

Biochemistry and the Language of Chemistry

The Chemical Foundation of Life: Weak Interactions in an Aqueous Environment

The Energetics of Life

Introduction to Proteins: the Primary Level of Protein Structure

The Three-Dimensional Structure of Proteins

Protein Function and Evolution

Enzymes: Biological Catalysts

Carbohydrates: Sugars, Saccharides, Glycans

Lipids, Membranes, and Cellular Transport

Chemical Logic of Metabolism

Carbohydrate Metabolism: Glycolysis, Gluconeogenesis, Glycogen Metabolism, and the Pentose Phosphate Pathway

The Citric Acid Cycle

Electron Transport, Oxidative Phosphorylation, and Oxygen Metabolism

Photosynthesis

Lipid Metabolism

Interorgan and Intracellular Coordination of Energy Metabolism in Vertebrates

Amino Acid and Nitrogen Metabolism

Nucleotide Metabolism

Mechanisms of Signal Transduction

Genes, Genomes, and Chromosomes

DNA Replication

DNA Repair, Recombination, and Rearrangement

Transcription and Post-Transcriptional Processing

Information Decoding: Translation and Post-Translational Protein Processing

Regulation of Gene Expression

Filters

Expression of genetic information involves first then .