Question 1

Which of the following statements concerning transfer RNA is true?

Accepted Answer

A)  It has the highest molecular weight of the commonly occurring forms of RNA. 
B)  It has no internal hydrogen bonding. 
C)  It bonds to amino acids in the course of protein synthesis. 
D)  It is the smallest of the RNA types 
E)  All of these are true. 
A)  It has the highest molecular weight of the commonly occurring forms of RNA. 
B)  It has no internal hydrogen bonding. 
C)  It bonds to amino acids in the course of protein synthesis. 
D)  It is the smallest of the RNA types 
E)  All of these are true.

Question 2

Protein synthesis can occur while the mRNA molecule is being synthesized in:

Accepted Answer

A)  Prokaryotes only. 
B)  Eukaryotes only. 
C)  Unicellular organisms only. 
D)  Multicellular organisms only. 
E)  Plants but not animals 
A)  Prokaryotes only. 
B)  Eukaryotes only. 
C)  Unicellular organisms only. 
D)  Multicellular organisms only. 
E)  Plants but not animals

Question 3

Which of the following statements concerning ribosomes is true?

Accepted Answer

A)  They consist of two RNA subunits, one of which is larger than the other. 
B)  They contain both RNA and protein. 
C)  They can be dissociated and reassembled by controlling the Mg2+ concentration of the medium. 
D)  All of these are true. 
A)  They consist of two RNA subunits, one of which is larger than the other. 
B)  They contain both RNA and protein. 
C)  They can be dissociated and reassembled by controlling the Mg2+ concentration of the medium. 
D)  All of these are true.

Question 4

Propeller twists occur in B-DNA so that

Accepted Answer

A)  Z-DNA can form 
B)  base pairing distances are optimized 
C)  base stacking can better occur 
D)  none of these 
A)  Z-DNA can form 
B)  base pairing distances are optimized 
C)  base stacking can better occur 
D)  none of these

Question 5

The fundamental differences between RNA and DNA are

Accepted Answer

A)  the organic bases only 
B)  bases, ribose units, and the phosphodiester linkage 
C)  bases, ribose units, and the glycosidic bond type 
D)  bases and the ribose units only 
A)  the organic bases only 
B)  bases, ribose units, and the phosphodiester linkage 
C)  bases, ribose units, and the glycosidic bond type 
D)  bases and the ribose units only

Question 6

Which of the following RNAs is the least abundant in a typical cell?

Accepted Answer

A)  mRNA 
B)  rRNA 
C)  snRNA 
D)  tRNA 
A)  mRNA 
B)  rRNA 
C)  snRNA 
D)  tRNA

Question 7

Base pairs with a propeller-twist

Accepted Answer

A)  are found only in Z-DNA 
B)  have optimum base stacking 
C)  bind water in the minor groove 
D)  have stronger hydrogen bonds than base pairs without a propeller twist 
A)  are found only in Z-DNA 
B)  have optimum base stacking 
C)  bind water in the minor groove 
D)  have stronger hydrogen bonds than base pairs without a propeller twist

Question 8

The melting profile for a DNA is found to differ in two different salt solutions. In 0.001 M NaCl, Tm = 55° C, and in 0.01 M NaCl, Tm = 65° C. The fundamental reason for this change is

Accepted Answer

A)  higher salt concentration increases the electrostatic repulsions between phosphates 
B)  the base stacking is more effective in high salt 
C)  hydrogen bonding between complementary bases in enhanced at high salt 
D)  higher salt concentration decreases the electrostatic repulsions between phosphates 
A)  higher salt concentration increases the electrostatic repulsions between phosphates 
B)  the base stacking is more effective in high salt 
C)  hydrogen bonding between complementary bases in enhanced at high salt 
D)  higher salt concentration decreases the electrostatic repulsions between phosphates

Question 9

Which conclusion can be drawn from the experimental observation that a single strand of DNA contains 2100 dA residues and 1800 dT residues?

Accepted Answer

A)  There must have been some loss of material in the extraction because the number of dA and dT residues must be the same. 
B)  This is a palindromic sequence. 
C)  There must be 2100 dT and 1800 dA residues on the complementary strand. 
D)  This must be prokaryotic DNA 
E)  None of these 
A)  There must have been some loss of material in the extraction because the number of dA and dT residues must be the same. 
B)  This is a palindromic sequence. 
C)  There must be 2100 dT and 1800 dA residues on the complementary strand. 
D)  This must be prokaryotic DNA 
E)  None of these

Question 10

The three dimensional structure of nucleic acids can include all except:

Accepted Answer

A)  Supercoiling 
B)  Base stacking 
C)  Hairpin loops 
D)  Circular molecules 
E)  All of these can be included in the three dimensional structure 
A)  Supercoiling 
B)  Base stacking 
C)  Hairpin loops 
D)  Circular molecules 
E)  All of these can be included in the three dimensional structure

Question 11

Comparison of DNA sequences between widely diverse organisms indicates that all organisms have genetic similarity.

Accepted Answer

A) True 
 B)False

Question 12

The outside diameter of a piece of DNA is closest to

Accepted Answer

A)  2 Å. 
B)  20 Å. 
C)  200 Å. 
D)  2000 Å. 
A)  2 Å. 
B)  20 Å. 
C)  200 Å. 
D)  2000 Å.

Question 13

Deoxythymidylate (dT) is a:

Accepted Answer

A)  purine base 
B)  pyrimidine base 
C)  pyrimidine based nucleotide 
D)  purine based nucleotide 
E)  nucleoside 
A)  purine base 
B)  pyrimidine base 
C)  pyrimidine based nucleotide 
D)  purine based nucleotide 
E)  nucleoside

Question 14

The following types of RNA are common to all organisms, except:

Accepted Answer

A)  mRNA 
B)  rRNA 
C)  snRNA 
D)  tRNA 
E)  All types are found in all organisms. 
A)  mRNA 
B)  rRNA 
C)  snRNA 
D)  tRNA 
E)  All types are found in all organisms.

Question 15

RNA is hydrolyzed in basic solution, but DNA is not. This occurs because

Accepted Answer

A)  thymine is found in DNA, and uracil is not 
B)  DNA is double stranded, and RNA is single stranded 
C)  DNA contains 2'-deoxyribose, but RNA does not 
D)  RNA has modified bases, but DNA does not 
A)  thymine is found in DNA, and uracil is not 
B)  DNA is double stranded, and RNA is single stranded 
C)  DNA contains 2'-deoxyribose, but RNA does not 
D)  RNA has modified bases, but DNA does not

Question 16

The backbone of nucleic acids consists of

Accepted Answer

A)  a phosphodiester bond between the 2' and 5' hydroxyl groups of neighboring sugars 
B)  a phosphodiester bond between the 3' and 5' hydroxyl groups of neighboring sugars 
C)  a glycosidic bond between a pyrimidine and a sugar 
D)  a glycosidic bond between a purine and a sugar 
A)  a phosphodiester bond between the 2' and 5' hydroxyl groups of neighboring sugars 
B)  a phosphodiester bond between the 3' and 5' hydroxyl groups of neighboring sugars 
C)  a glycosidic bond between a pyrimidine and a sugar 
D)  a glycosidic bond between a purine and a sugar

Question 17

The most recent discoveries in RNA research are:

Accepted Answer

A)  mRNA and tRNA 
B)  MiRNA and SiRNA 
C)  snRNA and snurps 
D)  tRNA and MiRNA 
A)  mRNA and tRNA 
B)  MiRNA and SiRNA 
C)  snRNA and snurps 
D)  tRNA and MiRNA

Question 18

The A and B forms of DNA

Accepted Answer

A)  both have 10 base pairs per turn of the helix 
B)  both have 11 base pairs per turn of the helix 
C)  are both left-handed helices 
D)  are both right-handed helices 
A)  both have 10 base pairs per turn of the helix 
B)  both have 11 base pairs per turn of the helix 
C)  are both left-handed helices 
D)  are both right-handed helices

Question 19

How does the enzyme ATP(CTP):tRNA nucleotidyletransferase aid in quality control of formation of tRNA?

Accepted Answer

A)  It puts a CCA on the 5' end 
B)  It puts a CCA on the 3' end 
C)  It puts a CCACCA on the 3' end of defective tRNA molecules or tRNA-like molelcules that are not true tRNA 
D)  None of these 
A)  It puts a CCA on the 5' end 
B)  It puts a CCA on the 3' end 
C)  It puts a CCACCA on the 3' end of defective tRNA molecules or tRNA-like molelcules that are not true tRNA 
D)  None of these

Question 20

In the DNA in chromatin, substitution mutations:

Accepted Answer

A)  are at a maximum in the linker regions 
B)  are at a maximum in the nucleosomes 
C)  occur maximally in the same places as deletion mutations 
D)  are rarely seen, but deletion mutations are common 
A)  are at a maximum in the linker regions 
B)  are at a maximum in the nucleosomes 
C)  occur maximally in the same places as deletion mutations 
D)  are rarely seen, but deletion mutations are common

Exam 9: Nucleic Acids: How Structure Conveys Information

Which of the following statements concerning transfer RNA is true?

Protein synthesis can occur while the mRNA molecule is being synthesized in:

Which of the following statements concerning ribosomes is true?

Propeller twists occur in B-DNA so that

The fundamental differences between RNA and DNA are

Which of the following RNAs is the least abundant in a typical cell?

Base pairs with a propeller-twist

The melting profile for a DNA is found to differ in two different salt solutions. In 0.001 M NaCl, Tm = 55° C, and in 0.01 M NaCl, Tm = 65° C. The fundamental reason for this change is

Which conclusion can be drawn from the experimental observation that a single strand of DNA contains 2100 dA residues and 1800 dT residues?

The three dimensional structure of nucleic acids can include all except:

Comparison of DNA sequences between widely diverse organisms indicates that all organisms have genetic similarity.

The outside diameter of a piece of DNA is closest to

Deoxythymidylate (dT) is a:

The following types of RNA are common to all organisms, except:

RNA is hydrolyzed in basic solution, but DNA is not. This occurs because

The backbone of nucleic acids consists of

The most recent discoveries in RNA research are:

The A and B forms of DNA

How does the enzyme ATP(CTP):tRNA nucleotidyletransferase aid in quality control of formation of tRNA?

In the DNA in chromatin, substitution mutations:

Biochemistry and the Organization of Cells

Water: the Solvent for Biochemical Reactions

Amino Acids and Peptides

The Three-Dimensional Structure of Proteins

Protein Purification and Characterization Techniques

The Behavior of Proteins: Enzymes

The Behavior of Proteins: Enzymes, Mechanisms, and Control

Lipids and Proteins Are Associated in Biological Membranes

Biosynthesis of Nucleic Acids: Replication

Transcription of the Genetic Code: Biosynthesis of RNA

Protein Synthesis: Translation of the Genetic Message

Nucleic Acid Biotechnology Techniques

Viruses, Cancer, and Immunology

The Importance of Energy Changes and Electron Transfer in Metabolism

Carbohydrates

Glycolysis

Storage Mechanisms and Control in Carbohydrate Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Lipid Metabolism

Photosynthesis

The Metabolism of Nitrogen

Integration of Metabolism: Cellular Signaling

Filters

The melting profile for a DNA is found to differ in two different salt solutions. In 0.001 M NaCl, T_m = 55° C, and in 0.01 M NaCl, T_m = 65° C. The fundamental reason for this change is