Question 1

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 2

The helix can be untwisted by the action of which type of topoisomerase?

Accepted Answer

A)  Type I only 
B)  Type II only 
C)  Both types I and II 
D)  Topoisomerases cannot untwist the helix. 
A)  Type I only 
B)  Type II only 
C)  Both types I and II 
D)  Topoisomerases cannot untwist the helix.

Question 3

The nucleotide sequence of DNA is which level of structure?

Accepted Answer

A)  primary 
B)  secondary 
C)  tertiary 
D)  quaternary 
A)  primary 
B)  secondary 
C)  tertiary 
D)  quaternary

Question 4

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 5

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

Accepted Answer

A) True 
 B)False

Question 6

​ The _____ structure in DNA refers to the supercoiling of the DNA molecule.

Accepted Answer

A)  primary 
B)  secondary 
C)  tertiary 
D)  quaternary 
A)  primary 
B)  secondary 
C)  tertiary 
D)  quaternary

Question 7

The strands in the double helix

Accepted Answer

A)  both run in the same 3' → 5' direction, i.e., they are parallel. 
B)  have their 3' → 5' directions opposed, i.e., they are anti-parallel. 
C)  can be either parallel or anti-parallel. 
D)  are perpendicular to one another. 
E)  None of these 
A)  both run in the same 3' → 5' direction, i.e., they are parallel. 
B)  have their 3' → 5' directions opposed, i.e., they are anti-parallel. 
C)  can be either parallel or anti-parallel. 
D)  are perpendicular to one another. 
E)  None of these

Question 8

Which of the following is not true?

Accepted Answer

A)  The amount of UV absorbance increases, but the wavelength does not change as DNA nears its melting point 
B)  Once DNA is denatured, it cannot renature 
C)  The melting temperature partially depends on the GC content 
D)  The nature of the solvent the DNA is in can affect the melting temperature 
A)  The amount of UV absorbance increases, but the wavelength does not change as DNA nears its melting point 
B)  Once DNA is denatured, it cannot renature 
C)  The melting temperature partially depends on the GC content 
D)  The nature of the solvent the DNA is in can affect the melting temperature

Question 9

Which of the following characteristics is associated with the B form of DNA?

Accepted Answer

A)  the sugars are located in the interior of the double helix 
B)  the distance between base pairs along the axis of the helix is 8 Å 
C)  the major and minor grooves are readily apparent 
D)  the planes of the bases make about a 20 degree angle with the helix axis 
A)  the sugars are located in the interior of the double helix 
B)  the distance between base pairs along the axis of the helix is 8 Å 
C)  the major and minor grooves are readily apparent 
D)  the planes of the bases make about a 20 degree angle with the helix axis

Question 10

The double helix of DNA is which level of structure?

Accepted Answer

A)  primary 
B)  secondary 
C)  tertiary 
D)  quaternary 
E)  None of these 
A)  primary 
B)  secondary 
C)  tertiary 
D)  quaternary 
E)  None of these

Question 11

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 12

Which of the following nucleobases is a purine?

Accepted Answer

A)  adenine 
B)  cytosine 
C)  thymine 
D)  uracil 
A)  adenine 
B)  cytosine 
C)  thymine 
D)  uracil

Question 13

Calculate the length\diameter ratio for the extended E. coli DNA (4 Å between adjacent nucleotides). E. coli DNA has 2 × 106 bp.

Accepted Answer

A)  4 × 105 
B)  1 × 105 
C)  3 × 108 
D)  3 × 106 
A)  4 × 105 
B)  1 × 105 
C)  3 × 108 
D)  3 × 106

Question 14

Topoisomerases are associated with

Accepted Answer

A)  production of RNA from DNA. 
B)  joining of nucleotide monomers to make polynucleotides. 
C)  supercoiling of DNA. 
D)  ribosomes. 
E)  All of these 
A)  production of RNA from DNA. 
B)  joining of nucleotide monomers to make polynucleotides. 
C)  supercoiling of DNA. 
D)  ribosomes. 
E)  All of these

Question 15

Quaternary structure refers to the non-covalent interaction(s) between polymeric units, such as two or more monomer protein units that noncovalently interact. Which of the following scenarios for nucleic acids most closely resembles quaternary structure?

Accepted Answer

A)  self-assembly of subunits in the tobacco mosaic virus 
B)  interaction of DNA with proteins 
C)  RNA and protein association in ribosomes 
D)  All of these 
E)  None of these 
A)  self-assembly of subunits in the tobacco mosaic virus 
B)  interaction of DNA with proteins 
C)  RNA and protein association in ribosomes 
D)  All of these 
E)  None of these

Question 16

The Tm for melting the double helix is:

Accepted Answer

A)  The temperature at which the helix starts to open. 
B)  The midpoint of the range over which the helix denatures. 
C)  The temperature at which the helix is completely open. 
D)  The energy needed to melt the DNA. 
E)  None of these is correct. 
A)  The temperature at which the helix starts to open. 
B)  The midpoint of the range over which the helix denatures. 
C)  The temperature at which the helix is completely open. 
D)  The energy needed to melt the DNA. 
E)  None of these is correct.

Question 17

Micro RNA technology is used in the treatment of _____.

Accepted Answer

A)  osteoporosis 
B)  migraine 
C)  hepatitis C 
D)  anaemia 
A)  osteoporosis 
B)  migraine 
C)  hepatitis C 
D)  anaemia

Question 18

Where can drugs or polypeptides bind to DNA?

Accepted Answer

A)  The minor groove only. 
B)  The major groove only. 
C)  Either the minor or major groove. 
D)  Neither the minor or major groove. 
A)  The minor groove only. 
B)  The major groove only. 
C)  Either the minor or major groove. 
D)  Neither the minor or major groove.

Question 19

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 20

Which of the following modifications is likely to happen to the mRNA in a eukaryotic cell?

Accepted Answer

A)  capping of the 5' end 
B)  addition of a poly-A tail to the 3' end 
C)  removal of intervening sequences (introns) 
D)  All of the above occur in eukaryotic cells. 
A)  capping of the 5' end 
B)  addition of a poly-A tail to the 3' end 
C)  removal of intervening sequences (introns) 
D)  All of the above occur in eukaryotic cells.

Exam 9: Nucleic Acids How Structure Conveys Information

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

The helix can be untwisted by the action of which type of topoisomerase?

The nucleotide sequence of DNA is which level of structure?

Which of the following statements concerning transfer RNA is true ?

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

​ The _____ structure in DNA refers to the supercoiling of the DNA molecule.

The strands in the double helix

Which of the following is not true?

Which of the following characteristics is associated with the B form of DNA?

The double helix of DNA is which level of structure?

Which of the following statements concerning ribosomes is true ?

Which of the following nucleobases is a purine?

Calculate the length\diameter ratio for the extended E. coli DNA (4 Å between adjacent nucleotides). E. coli DNA has 2 × 106 bp.

Topoisomerases are associated with

Quaternary structure refers to the non-covalent interaction(s) between polymeric units, such as two or more monomer protein units that noncovalently interact. Which of the following scenarios for nucleic acids most closely resembles quaternary structure?

The Tm for melting the double helix is:

Micro RNA technology is used in the treatment of _____.

Where can drugs or polypeptides bind to DNA?

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

Which of the following modifications is likely to happen to the mRNA in a eukaryotic cell?

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 the 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 _____ structure in DNA refers to the supercoiling of the DNA molecule.

Calculate the length\diameter ratio for the extended E. coli DNA (4 Å between adjacent nucleotides). E. coli DNA has 2 × 10⁶ bp.

The T_m for melting the double helix is: