Which of the following descriptions best fits the class of molecules known as nucleotides?

Question 1 (1 point)
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Which of the following descriptions best fits the class of molecules known as nucleotides?


Question 1 options:

 

A)  a nitrogen base and a phosphate group  
 
 

B)  a nitrogen base and a five carbon sugar only  
 
 

C)  a nitrogen base, a phosphate group, and a five carbon sugar  
 
 

D)  a five carbon sugar, a phosphate group, and a purine  
 
 

E)  a pyrimidine, a purine, and a six carbon sugar  
 
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Question 2 (1 point)
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In DNA, the terms 3’ and 5’ refer to the
Question 2 options:

 

A)  bonds that form between  adenine and thymine and between guanine and cytosine

 
 
 

B)  carbon atoms of deoxyribose to which phosphate groups may bond
 
 
 

C)  cross-linking of the third and fifth carbon atoms of deoxyribose
 
 
 

D)  carbon or nitrogen atoms on the rings of purine or pyrimidine bases
 
 
 

E)  bonding between purines and deoxyribose and between pyrimidines and deoxyribose
 
 
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Question 3 (1 point)
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Through their experiments, Hershey and Chase made what contributions to our understanding of genetics?


Question 3 options:

 

A)  DNA alone is the hereditary material and not protein  
 
 

B)  How the bacteriaphage virus infects bacteria  
 
 

C)  Discovering the structure of DNA  
 
 

D)  Protein is in the DNA structure  
 
 

E)  Both A and B are correct  
 
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Question 4 (1 point)
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Use the following diagram to answer questions 4 and 5: Chose the appropriate letter.

Diagram
 In the Meselson-Stahl experiment, bacteria were grown in a medium containing 15N (radioactive nitrogen) and were then transferred to an environment containing 14N.  Which of the above results would be expected after two DNA replications?


Question 4 options:

 

A)  A  
 
 

B)  B  
 
 

C)  C  
 
 

D)  D  
 
 

E)  E  
 
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Question 5 (1 point)
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Use the following diagram to answer questions 4 and 5: Chose the appropriate letter.

Diagram
 Microorganisms from another planet where found on a meteor.  Analysis shows that it is a carbon based life form that has DNA. These cells were placed in 15N for several generations and then transferred to 14N medium.  Which pattern in the above figure would you expect if the DNA was replicated in a conservative manner?


Question 5 options:

 

A)  A  
 
 

B)  B  
 
 

C)  C  
 
 

D)  D  
 
 

E)  E  
 
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Question 6 (1 point)
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DNA ligase is an enzyme that
Question 6 options:

 

A)  is used to tie parts of a DNA molecule together  
 
 

B)  is used in mutation repair of DNA molecules  
 
 

C)  works with DNA and RNA polymerase at various times in the cell  
 
 

D)  none of these  
 
 

E)  all of these  
 
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Question 7 (1 point)
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When a ribosome first attaches to an m-RNA, two t-RNAs bind to the ribosome.  The first t-RNA that recognizes the initiation codon binds to the:


Question 7 options:

 

A)  The (A) site of the ribosome only  
 
 

B)  The (P) site of the ribosome only  
 
 

C)  The large ribosomal subunit only  
 
 

D)  Second t-RNA before attaching to the ribosome  
 
 

E)  None of the above
 
 
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Question 8 (1 point)
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Which of the following enzymes synthesizes short segments of RNA?
Question 8 options:

 

A)  helicase  
 
 

B)  exonuclease  
 
 

C)  ligase  
 
 

D)  DNA polymerase  
 
 

E)  primase  
 
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Question 9 (1 point)
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When a double stranded DNA molecule is heated, it denatures into two single stranded molecules.  The reason for that is that


Question 9 options:

 

A)  the proteins associated with the double helix are denatured and can no longer hold the DNA strands together

 
 
 

B)  the heat causes the helix to straighten, breaking the connections between the bases
 
 
 

C)  the heat breaks the hydrogen bonds holding the bases together in the centre of the molecule but does not affect the covalent bonds of the backbone
 
 
 

D)  the heat denatures the bases, preventing them from hydrogen bonding with each other.
 
 
 

E)  The heat causes the phosphate groups to ionize, preventing them from hydrogen bonding to the bases
 
 
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Question 10 (1 point)
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Beadle and Tatum proposed the one gene-one enzyme concept.  This hypothesis could be restated in which of the following ways?


Question 10 options:

 

A)  One DNA molecule contains the information to make one enzyme

 
 
 

B)  A given sequence of DNA nucleotides contains the information to make one enzyme
 
 
 

C)  Each gene contains the information to make one enzyme, one lipid, and one carbohydrate
 
 
 

D)  Each gene is actually an enzyme that catalyzes the production of one protein
 
 
 

E)  Each polypeptide is the result of the activity of one enzyme
 
 
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Question 11 (1 point)
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A possible sequence of nucleotides in the DNA that would code for the polypeptide sequence –Phenylalanine, Leucine-Tyrosine-Cysteine- would be:


Question 11 options:

 

A)  TTG-CTA-CAG-TAG  
 
 

B)  AAU-GAC-GUC-AUA  
 
 

C)  AUG-CTG-CAG-TAT  
 
 

D)  AAA-AAT-ATA-ACA  
 
 

E)  UGU-UAU-UUA-UUU  
 
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Question 12 (1 point)
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A particular eukaryotic protein is 300 amino acids long.  Which of the following could be the number of nucleotides in the DNA that codes for this protein?


Question 12 options:

 

A)  3  
 
 

B)  100  
 
 

C)  300  
 
 

D)  900  
 
 

E)  1800  
 
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Question 13 (1 point)
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If cytosine makes up 22 % of the nucleotides in a sample of DNA from an organism, then adenine would make up what percent of the bases?


Question 13 options:

 

A)  22  
 
 

B)  44  
 
 

C)  28  
 
 

D)  56  
 
 

E)  It cannot be determined from the information provided  
 
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Question 14 (1 point)
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Which of the following is NOT related to ribosomal activity?


Question 14 options:

 

A)  A site  
 
 

B)  spliceosome  
 
 

C)  codon recognition  
 
 

D)  peptide bond formation  
 
 

E)  P site  
 
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Question 15 (1 point)
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The processing of the primary transcript involves


Question 15 options:

 

A)  the removal of introns and the splicing together of exons  
 
 

B)  the removal of exons and the splicing together of introns  
 
 

C)  the addition of a guanine cap and a poly-A tail  
 
 

D)  the attachment of introns to ribosomal RNA  
 
 

E)  Both A and C are correct  
 
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Question 16 (1 point)
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A frameshift mutation could result from
Question 16 options:

 

A)  a base insertion only  
 
 

B)  a base deletion only  
 
 

C)  a base substitution only  
 
 

D)  deletion of three consecutive bases  
 
 

E)  either an addition or a deletion of a base  
 
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Question 17 (1 point)
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A silent mutation can result from:
Question 17 options:

 

A)  the insertion of a base pair  
 
 

B)  the substitution of a base pair that results in the same amino acid
 
 
 

C)  the deletion of a base pair
 
 
 

D)  the substitution of a base pair which lies in an intron and is eventually spliced out by spliceosomes
 
 
 

E)  B and D
 
 
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Question 18 (1 point)
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mRNA


Question 18 options:

 

A)  makes up the ribosomes in the cell  
 
 

B)  carries the genetic information from the nucleus into the cytoplasm
 
 
 

C)  
is helical

 
 
 

D)  is a double strand  
 
 

E)  always codes for all 20 amino acids
 
 
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Question 19 (1 point)
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Which of the following statements is NOT true for DNA replication?


Question 19 options:

 

A)  the enzyme DNA polymerase checks for errors in base pairing
 
 
 

B)  each strand acts as a template for the synthesis of the new strands
 
 
 

C)  two identical DNA molecules are formed
 
 
 

D)  DNA is built continuously on the lagging strand
 
 
 

E)  The lagging strand is built in Okazaki fragments which are later joined
 
 
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Question 20 (1 point)
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Which statement(s) about the trp operon in E. coli is correct?


Question 20 options:

 

A)  It is an example of transcriptional regulation
 
 
 

B)  An inducer binds to a repressor molecule and activates transcription
 
 
 

C)  A corepressor binds to a repressor molecule and stops transcription
 
 
 

D)  Lactose binds directly to the operator and activates it
 
 
 

E)  Both a) and b) are correct
 
 
 

F)  Both c) and d) are incorrect
 
 
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Question 21 (1 point)
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Which of the following statements concerning protein synthesis is NOT true?


Question 21 options:

 

A)  proteins are assembled with the help of ribosomes
 
 
 

B)  tRNAs carry amino acids to the ribosome-mRNA complex
 
 
 

C)  ribosomes attach to the mRNA
 
 
 

D)  the mRNA contains the anticodons
 
 
 

E)  a part of the information on the DNA is transcribed into mRNA
 
 
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Question 22 (1 point)
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Except for the T-U exchange, the tRNA anticodon is identical to


Question 22 options:

 

A)  template strand
 
 
 

B)  coding strand
 
 
 

C)  mRNA
 
 
 

D)  amino acid it carries
 
 
 

E)  A-site in the ribosome
 
 
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Question 23 (1 point)
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Which of the following statements is true?


Question 23 options:

 

A)  Prokaryotic  and eukaryotic DNA have the same number of nucleotides
 
 
 

B)  Prokarytoic genes have introns
 
 
 

C)  In both prokaryotes and eukaryotes, the primary transcript needs to be modified for the mRNA to be functionable
 
 
 

D)  Only in eukaryotes is the primary transcript modified in a process called splicing.
 
 
 

E)  Capping and tailing does not occur in eukaryotes
 
 
 

F)  Both c) and e) are correct
 
 
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Question 24 (1 point)
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Which of the following mutations is potentially the most harmful?


Question 24 options:

 

A)  base-pair substitution at the end
 
 
 

B)  a frameshift mutation at the beginning
 
 
 

C)  a frameshift mutation at the end
 
 
 

D)  a) and c) are always equally harmful
 
 
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Question 25 (1 point)
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During translation, chain elongation continues until what happens?


Question 25 options:

 

A)  no further amino acids are needed by the cell
 
 
 

B)  all tRNAs are empty
 
 
 

C)  the polypeptide is long enough
 
 
 

D)  chain termination codons are read
 
 
 

E)  ribosomes run off the end of mRNA
 
 
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Question 26 (1 point)
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Ligase forms phosphodiester bonds
Question 26 options:

 True
 False
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Question 27 (1 point)
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Single stranded binding proteins assist transcription
Question 27 options:

 True
 False
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Question 28 (1 point)
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A replication fork is formed in transcription
Question 28 options:

 True
 False
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Question 29 (1 point)
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Transcription factors assist RNA polymerase bind to the DNA
Question 29 options:

 True
 False
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Question 30 (1 point)
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Capping and tailing are done before translation
Question 30 options:

 True
 False
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Question 31 (1 point)
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Proteins are modified before they leave the cell
Question 31 options:

 True
 False
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Question 32 (1 point)
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Operons are found in prokaryotes
Question 32 options:

 True
 False
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Question 33 (1 point)
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cAMP binds to the activator protein in the lac operon to activate transcription
Question 33 options:

 True
 False
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Question 34 (1 point)
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Vectors can be bacteria or viruses
Question 34 options:

 True
 False
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Question 35 (1 point)
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Restriction endonucleases make it possible to make recombinant DNA
Question 35 options:

 True
 False