General, Organic & Biological Chemistry, 5e (Timberlake)
Chapter 21 Nucleic Acids and Protein Synthesis
21.1 Multiple-Choice Questions
1) A ______consists of a nitrogen-containing a base and a sugar.
A) nucleoside
B) base pair
C) nucleotide
D) complementary base
E) pyrimidine
Answer: A
Objective: 21.1
Global Outcomes: GO2
2) A ______consists of a nitrogen-containing base, a sugar, and a phosphate group.
A) nucleoside
B) base pair
C) nucleotide
D) complementary base
E) purine
Answer: C
Objective: 21.1
Global Outcomes: GO2
3) Which of the following can NOT be found in a nucleotide of RNA?
A) purine
B) pyrimidine
C) phosphate
D) ribose
E) deoxyribose
Answer: E
Objective: 21.1
Global Outcomes: GO2
4) Which of the following is found in RNA but not in DNA?
A) thymine
B) uracil
C) guanine
D) cytosine
E) deoxyribose
Answer: B
Objective: 21.1
Global Outcomes: GO2
5) Which of the following will not be found in DNA?
A) adenine
B) thymine
C) guanine
D) cytosine
E) ribose
Answer: E
Objective: 21.1
Global Outcomes: GO2
6) Which of the following can be found in DNA?
A) ribose
B) GMP
C) uracil
D) deoxyadenosine
E) FMN
Answer: D
Objective: 21.1
Global Outcomes: GO2
7) Guanine is one example of a nitrogen base that is a
A) cofactor.
B) 5-carbon sugar.
C) phosphodiester.
D) pyrimidine.
E) purine.
Answer: E
Objective: 21.1
Global Outcomes: GO2
8) The nucleotides in the backbone of DNA are held together by ______bonds.
A) hydrogen
B) peptide
C) phosphodiester
D) glycosidic
E) ionic
Answer: C
Objective: 21.2
Global Outcomes: GO2
9) The bonds that link the base pairs in the DNA double helix are
A) ionic bonds.
B) peptide bonds.
C) hydrogen bonds.
D) hydrophobic bonds.
E) ester bonds.
Answer: C
Objective: 21.2
Global Outcomes: GO2
10) Which of the following hold two strands of DNA in an a helix?
A) ester linkages
B) disulfide linkages
C) peptide bonds
D) hydrogen bonds
E) glycosidic linkages
Answer: D
Objective: 21.2
Global Outcomes: GO2
11) The base sequence of the strand of DNA complementary to the segment
5' T-G-G-C-A-A-C 3' is
A) 3' T-G-G-C-A-A-C 5'.
B) 3' A-C-C-G-T-T-G 5'.
C) 3' A-C-C-G-U-U-G 5'.
D) 3' U-C-C-G-T-T-G 5'.
E) 3' A-C-G-C-T-U-G 5'.
Answer: B
Objective: 21.3
Global Outcomes: GO2
12) When DNA duplicates itself, the correct placement of the nucleotides is accomplished by
A) complementary base pairing.
B) polymerase.
C) enzyme matching.
D) base matching.
E) transcription.
Answer: A
Objective: 21.3
Global Outcomes: GO2
13) When DNA replicates, a guanine forms a base pair with
A) uracil.
B) adenine.
C) guanine.
D) thymine.
E) cytosine.
Answer: E
Objective: 21.3
Global Outcomes: GO2
14) Which one of the following base pairs is found in DNA?
A) adenine-thymine
B) adenine-guanine
C) cytosine-thymine
D) adenine-uracil
E) guanine-uracil
Answer: A
Objective: 21.3
Global Outcomes: GO2
15) Which of the following statements is TRUE?
A) Cytosine and Thymine are a complementary base pair that forms 3 hydrogen bonds.
B) Thymine and Guanine are a complementary base pair that forms 3 hydrogen bonds.
C) Cytosine and Guanine are a complementary base pair that forms 2 hydrogen bonds.
D) Thymine and Adenine are a complementary base pair that forms 2 hydrogen bonds.
E) Thymine and Guanine are a complementary base pair that forms 2 hydrogen bonds.
Answer: D
Objective: 21.3
Global Outcomes: GO2
16) The two strands of the double helix of DNA are held together by
A) hydrogen bonds.
B) covalent bonds.
C) dipole-dipole interactions.
D) ionic bonds.
E) sugar-to-phosphate bonds.
Answer: A
Objective: 21.3
Global Outcomes: GO2
17) Which of the following is NOT a step in DNA replication?
A) mRNA sends a message to form a new strand of DNA.
B) A base on the DNA pairs with its complementary base free in solution.
C) DNA polymerase forms bonds between a 5'-phosphate of one nucleotide and a 3'-hydroxyl of another.
D) On one strand the DNA is synthesized continuously.
E) DNA ligase connects short segments of DNA on one strand.
Answer: A
Objective: 21.4
Global Outcomes: GO2
18) The two new DNA molecules formed in replication
A) are complementary to the original DNA.
B) both contain only two new daughter DNA strands.
C) both contain only the parent DNA strands.
D) contain one parent and one daughter strand.
E) are identical, with one containing both parent strands, and the other containing both daughter strands.
Answer: D
Objective: 21.4
Global Outcomes: GO2
19) What is the process in which the DNA double helix unfolds, and each strand serves as a template for the synthesis of a new strand?
A) transcription
B) complementation
C) translation
D) replication
E) restriction
Answer: D
Objective: 21.4
Global Outcomes: GO2
20) The backbone of the helix of DNA is held together by
A) hydrogen bonds.
B) covalent bonds.
C) dipole-dipole interactions.
D) ionic bonds.
E) sugar-to-phosphate bonds.
Answer: E
Objective: 21.4
Global Outcomes: GO2
21) Which of the following types of RNA carries the genetic information from DNA in the nucleus to the cytoplasm for protein synthesis?
A) mRNA
B) histone RNA
C) rRNA
D) tRNA
E) sRNA
Answer: A
Objective: 21.5
Global Outcomes: GO2
22) In transcription
A) the mRNA produced is identical to the parent DNA.
B) a double helix containing one parent strand and one daughter strand is produced.
C) uracil pairs with thymine.
D) both strands of the DNA are copied.
E) the mRNA produced is complementary to one strand of the DNA.
Answer: E
Objective: 21.5
Global Outcomes: GO2
23) Which of the following is a section of mRNA produced from the DNA template below?
3' A-T-A-G-C-T-A 5'
A) 5' A-T-A-G-C-T-A 3'
B) 5' A-U-A-G-C-U-A 3'
C) 5' U-A-U-C-G-A-U 3'
D) 5' U-U-U-G-C-U-U 3'
E) 5' T-A-T-C-G-A-T 3'
Answer: C
Objective: 21.5
Global Outcomes: GO2
24) Which of the following is a section of mRNA produced from the DNA template below?
3' A-A-G-C-G-A-A 5'
A) 5' A-T-A-G-C-T-A 3'
B) 5' A-U-A-G-C-U-A 3'
C) 5' U-A-U-C-G-A-U 3'
D) 5' U-U-U-G-C-U-U 3'
E) 5' T-A-T-C-G-A-T 3'
Answer: D
Objective: 21.5
Global Outcomes: GO2
25) Which one of these base pairs is found in RNA?
A) guanine-cytosine
B) adenine-cytosine
C) adenine-thymine
D) adenine-guanine
E) guanine-thymine
Answer: A
Objective: 21.5
Global Outcomes: GO2
26) In the synthesis of mRNA, an adenine in the DNA pairs with
A) uracil.
B) adenine.
C) guanine.
D) thymine.
E) cytosine.
Answer: A
Objective: 21.5
Global Outcomes: GO2
27) A DNA template having the base sequence 3' A-G-A-T-G-A 5' would produce a mRNA with a base sequence of
A) 5' A-G-A-T-G-A 3'.
B) 5' U-C-U-A-C-U 3'.
C) 5' T-C-T-U-C-T 3'.
D) 5' T-C-T-A-C-A 3'.
E) 5' A-C-A-U-C-A 3'.
Answer: B
Objective: 21.5
Global Outcomes: GO2
28) When mRNA is synthesized using the information from DNA, the process is called
A) transportation.
B) transposition.
C) transcription.
D) translation.
E) transliteration.
Answer: C
Objective: 21.5
Global Outcomes: GO2
29) The anticodon is
A) identical to the codon on DNA.
B) complementary to the codon on DNA.
C) identical to the codon on mRNA.
D) complementary to the codon on mRNA.
E) complementary to the codon on tRNA.
Answer: D
Objective: 21.5
Global Outcomes: GO2
30) A set of directions in the DNA base sequence for the synthesis of a protein is a(n)
A) structural gene.
B) promotor.
C) operator.
D) codon.
E) regulatory gene.
Answer: A
Objective: 21.5
Global Outcomes: GO2
31) Which of the following types of RNA has a large subunit and a small subunit?
A) mRNA
B) histone RNA
C) rRNA
D) tRNA
E) sRNA
Answer: A
Objective: 21.5
Global Outcomes: GO2
32) Some sections of a DNA molecule do not code for protein synthesis. These segments are called
A) codons.
B) anticodons.
C) Okazaki fragments.
D) introns.
E) exons.
Answer: D
Objective: 21.5
Global Outcomes: GO2
33) Codons are base pair sequences that
A) signal the start of DNA synthesis.
B) signal the end of DNA synthesis.
C) code for amino acids.
D) signal the start of RNA synthesis.
E) code for one or more bases in mRNA.
Answer: C
Objective: 21.6
Global Outcomes: GO2
34) The codon is found on ______, and the anticodon is found on ______.
A) mRNA; tRNA
B) tRNA; mRNA
C) rRNA; tRNA
D) ribosomes; tRNA
E) mRNA; rRNA
Answer: A
Objective: 21.6
Global Outcomes: GO2
35) Translation is the process whereby
A) DNA is synthesized from DNA.
B) DNA is synthesized from mRNA.
C) protein is synthesized from DNA.
D) protein is synthesized from mRNA.
E) mRNA is synthesized from DNA.
Answer: D
Objective: 21.7
Global Outcomes: GO2
36) Which of the following is not a step in protein synthesis?
A) activation of tRNA
B) initiation
C) elongation
D) termination
E) unwinding of two strands of mRNA
Answer: E
Objective: 21.7
Global Outcomes: GO2
37) A tRNA is activated when it
A) attaches to mRNA.
B) attaches to its specific amino acid.
C) attaches to the ribosome.
D) leaves the ribosome.
E) releases its specific amino acid.
Answer: B
Objective: 21.7
Global Outcomes: GO2
38) During protein synthesis, the codon for an amino acid is found on
A) DNA.
B) rRNA.
C) tRNA.
D) mRNA.
E) sRNA.
Answer: D
Objective: 21.7
Global Outcomes: GO2
39) The anticodon of U-A-G is
A) A-T-C.
B) U-A-G.
C) A-A-C.
D) A-U-C.
E) G-A-U.
Answer: D
Objective: 21.7
Global Outcomes: GO2
40) Mutations are the result of
A) alterations in the phosphate of the DNA backbone.
B) exposure to water in utero.
C) physical trauma in the mother's childhood.
D) alterations in the sugar component of the DNA backbone.
E) alterations in the DNA base sequence.
Answer: E
Objective: 21.8
Global Outcomes: GO7
41) The result of a defective enzyme caused by a mutation in the DNA nucleotide sequence is
A) a genetic disease.
B) AIDS.
C) HIV.
D) recombinant DNA.
E) translocation.
Answer: A
Objective: 21.8
Global Outcomes: GO7
42) When a mutation occurs by elimination of one base in a DNA sequence, this mutation is called a
A) deletion mutation.
B) retrovirus insertion.
C) substitution mutation.
D) translocation mutation.
E) viral mutation.
Answer: A
Objective: 21.8
Global Outcomes: GO7
43) In the study of genetics, the abbreviation PCR refers to
A) purine chain repression.
B) pyrimidine complement restriction.
C) purine coded ribose.
D) protein combination and replication.
E) polymerase chain reaction.
Answer: E
Objective: 21.9
Global Outcomes: GO7
44) Recombinant DNA technology requires the use of bacterial
A) plasmids.
B) mitochondria.
C) endoplasmic reticulum.
D) ribosomes.
E) cell walls.
Answer: A
Objective: 21.9
Global Outcomes: GO7
45) One therapeutic product now available due to recombinant DNA technology is
A) measles vaccine.
B) penicillin.
C) human growth hormone.
D) sulfamethoxazole.
E) tamoxifen.
Answer: C
Objective: 21.9
Global Outcomes: GO7
46) DNA fingerprinting uses ______to produce DNA fragments that can be separated and screened for the presence of genetic diseases.
A) extracellular DNA
B) restriction enzymes
C) bacterial plasmids
D) anticodons
E) codons
Answer: B
Objective: 21.9
Global Outcomes: GO7
47) The purpose of the human genome project was to
A) identify genes responsible for noninheritable diseases.
B) determine how to clone human DNA.
C) identify substrates for the polymerase chain reaction.
D) learn how to clone bacterial DNA.
E) map the locations of all the genes in human DNA.
Answer: E
Objective: 21.9
Global Outcomes: GO7
48) Which of the following is used in the preparation of recombinant DNA?
A) RNA polymerase
B) DNA polymerase
C) repressor protein
D) restriction enzyme
E) enzyme induction
Answer: D
Objective: 21.9
Global Outcomes: GO7
49) The insertion of new DNA into the plasmid DNA of a bacterium produces
A) viral DNA.
B) DNA fingerprints.
C) recombinant DNA.
D) ribosomes.
E) restriction enzymes.
Answer: C
Objective: 21.9
Global Outcomes: GO7
50) The polymerase chain reaction is used in
A) preparing recombinant DNA.
B) transcription.
C) DNA fingerprinting.
D) translation.
E) replication.
Answer: C
Objective: 21.9
Global Outcomes: GO7
51) A restriction enzyme functions to
A) prevent the DNA from leaving the nucleus.
B) limit the number of replications a DNA molecule can achieve.
C) cut a large DNA double helix into smaller fragments.
D) stop the elongation step of protein synthesis.
E) eliminate a virus from a cell.
Answer: C
Objective: 21.9
Global Outcomes: GO7
52) Small living particles, with 3 to 200 genes, that cannot replicate without a host cell are called
A) recombinant DNAs.
B) viruses.
C) bacteria.
D) tumors.
E) plasmids.
Answer: B
Objective: 21.10
Global Outcomes: GO2
53) A virus that contains RNA as its genetic material is a
A) genetically engineered virus.
B) bacteria.
C) recombinant DNA.
D) retrovirus.
E) vaccine.
Answer: D
Objective: 21.10
Global Outcomes: GO2
54) Protease inhibitors, which are effective anti-HIV drugs,
A) are nucleoside analogs.
B) prevent reverse transcription.
C) prevent synthesis of viral proteins.
D) prevent mRNA synthesis.
E) prevent activation of tRNA.
Answer: C
Objective: 21.10
Global Outcomes: GO2
21.2 True/False Questions
1) Adenine is a purine.
Answer: TRUE
Objective: 21.1
Global Outcomes: GO2
2) Uracil is a pyrimidine.
Answer: TRUE
Objective: 21.1
Global Outcomes: GO2
3) DNA is a protein.
Answer: FALSE
Objective: 21.1
Global Outcomes: GO2
4) A nucleotide consists of only a base and a sugar.
Answer: FALSE
Objective: 21.1
Global Outcomes: GO2
5) DNA differs from RNA in the sugar it contains.
Answer: TRUE
Objective: 21.1
Global Outcomes: GO2
6) The sequence of bases in a nucleic acid is the primary structure.
Answer: TRUE
Objective: 21.2
Global Outcomes: GO2
7) The backbone of a nucleic acid is the nitrogen bases.
Answer: FALSE
Objective: 21.2
Global Outcomes: GO2
8) In the DNA double helix, a purine can only bond with a pyrimidine.