Test 3 
Bio 160  Genetics and Human Affairs
March 24, 2010

1.	 Who was the first to discover that inborn errors of metabolism are due to enzymes?   
A. 	
 Franklin 	

D. 	
 Griffith 	

B. 	
 Watson and Crick 	

E. 	
 Avery 	

C. 	
 Garrod 	

 	

 
2.	 The current model of DNA structure was proposed by:   
A. 	
 Chargaff, Wilkins and Franklin 	

D. 	
 Charles Darwin 	

B. 	
 Avery, MacLeod and McCarty 	

E. 	
 Linus Pauling 	

C. 	
 Watson and Crick 	

 	

 
3.	The structure of DNA is_______, while RNA is generally__________.   
A. 	
 double-stranded; single-stranded 	

C. 	
 compact; loose 	

B. 	
 single-stranded; double-stranded 	

D. 	
 loose; compact 	

	
 
4.	 The two strands in a DNA molecule are:   
A. 	
 identical 	

C. 	
 antiparallel 	

B. 	
 complementary 	

D. 	
 b and c 	

	
 
5.	 DNA replication is:   
A. 	
 Semi-conservative 	

C. 	
 Conservative 	

B. 	
 Dispersive 	

D. 	
 Discontinuous on both strands 	

	
 
6.	 Which of the following  is found in a nucleotide?   
A. 	
 five carbon sugar 	

C. 	
 phosphate group 	

B. 	
 nitrogenous base 	

D. 	
 all of the above 	

	
 
7.	 Which mode of information transfer usually does not occur?   
A. 	
 DNA to DNA 	

C. 	
 DNA to protein 	

B. 	
 DNA to RNA 	

D. 	
 All occur in a working cell 	

	
 
8.	 DNA nucleotides pair via hydrogen bonds.  The base thymine forms a complementary base pair with:   
A. 	
 adenine 	

C. 	
 quanine 	

B. 	
 thymine 	

D. 	
 cytosine 	

	
 
9.	The process of copying a gene's DNA sequence into a sequence of RNA is called   
A. 	
 replication 	

C. 	
 translation 	

B. 	
 transcription 	

D. 	
 PCR 	

	
 
10.	Which molecule contains codons?   
A. 	
 DNA 	

C. 	
 tRNA 	

B. 	
 mRNA 	

D. 	
 rRNA 	

	
 
11.	RNA is transcribed using the __________strand of DNA   
A. 	
 coding 	

C. 	
 template 	

B. 	
 alternate 	

D. 	
 non-template 	

	
 
12.	Loops, coils and sheets are introduced at the _______ structure of the protein.   
A. 	
 primary 	

C. 	
 tertiary 	

B. 	
 secondary 	

D. 	
 quaternary 	

	
 
13.	 Energy is required to break the hydrogen bonds holding the bases together.  Which pair will be the most difficult to separate?   
A. 	
 A -T 	

C. 	
 A - C 	

B. 	
 C - G 	

D. 	
 G -T 	

	
 
14.	 Translation terminates when_________.   
A. 	
 the A site is empty 	

C. 	
 a release factor is present in the P site 	

B. 	
 a stop codon is present in the A site 	

D. 	
 Translation reached the end of the mRNA 	

	
 
15.	 Identification of DNA as a helical molecule was first shown in 1952 by:   
A. 	
 Franklin 	

C. 	
 Chargaff 	

B. 	
 Watson and Crick 	

D. 	
 Griffith 	

	
 
16.	 _________ are the building blocks of DNA   
A. 	
 Histones 	

C. 	
 Nucleotides 	

B. 	
 Proteins 	

D. 	
 Phosphates 	

	
 
17.	 If DNA polymerase could add bases in the 3' to 5' direction, there would be no need for:   
A. 	
 DNA ligase 	

C. 	
 helicase 	

B. 	
 Okazaki fragments 	

D. 	
 PCR 	

	
 
18.	A DNA strand with the sequence 3' AACGTAACG 5' is transcribed. What is the sequence of the mRNA molecule synthesized?   
A. 	
 5' AACGTTAACG 3' 	

C. 	
 5' AACGUAACG 3' 	

B. 	
 5' UUGCAUUGC 3' 	

D. 	
 5' TTGCATTGC 3' 	

	
 
19.	 If DNA is compared to a spiral staircase, then steps of the staircase would correspond to:   
A. 	
 Sugars 	

D. 	
 Nucleotides 	

B. 	
 Hydrogen bonds 	

E. 	
 Phosphates 	

C. 	
 Base pairs 	

 	

 
20.	 In humans, DNA in the nucleus winds around proteins called:   
A. 	
 Histones 	

D. 	
 Ribosomes 	

B. 	
 Histosomes 	

E. 	
 Barr bodies 	

C. 	
 Karyosomes 	

 	

 
21.	 The nitrogenous bases adenine and thymine are:   
A. 	
 Both purines 	

D. 	
 A pyrimidine and a purine, respectively 	

B. 	
 A purine and a pyrimidine, respectively 	

E. 	
 Amino acids 	

C. 	
 Both pyrimidines 	

 	

 
22.	 DNA strands are antiparallel, so replication proceeds:   
A. 	
 Continuously on both strands 	

D. 	
 Continuously on both strands for a time and then discontinuously 	

B. 	
 Continuously on one strand and discontinuously on the other 	

E. 	
 Discontinuously using amino acids 	

C. 	
 Discontinuously on both strands 	

 	

 
23.	 Chargaff showed that if human DNA contained 30% adenine, then the percentage of thymine would be:   
A. 	
 20% 	

D. 	
 40% 	

B. 	
 30% 	

E. 	
 Cannot be determined 	

C. 	
 60% 	

 	

 
24.	 _______ bonds form between amino acids during elongation.   
A. 	
 Phosphodiester 	

D. 	
 Hydrogen 	

B. 	
 Disulfide 	

E. 	
 Glycine 	

C. 	
 Peptide 	

 	

 
25.	 Some genes code for RNAs that do not specify a protein.   
A. 	
 True 	

B. 	
 False 	

	
 
26.	 The structure of DNA:   
A. 	
 Is symmetrical 	

D. 	
 Turns to form a helix 	

B. 	
 Pairs purines with pyrimidines 	

E. 	
 All of these 	

C. 	
 Is antiparallel 	

 	

 
27.	 Which of the following best illustrates the central dogma of biology?   
A. 	
 DNA  RNA  protein 	

C. 	
 Protein  DNA protein 	

B. 	
 RNA  DNA  protein 	

D. 	
 Protein  RNA  DNA 	

	
 
28.	 Which of these is not found in RNA?   
A. 	
 Nitrogen 	

D. 	
 Purines 	

B. 	
 Phosphate 	

E. 	
 Ribose 	

C. 	
 Deoxyribose 	

 	

 
29.	 How do transcription factors function in the expression of genes?   
A. 	
 They initiate translation 	

D. 	
 They halt RNA polymerase at the end of transcription 	

B. 	
 They associate to initiate translation 	

E. 	
 They bring amino acids into the ribosome 	

C. 	
 They turn transcription of specific genes on or off 	

 	

 
30.	 Transcription and replication are alike in that both:   
A. 	
 Are guided by complementary base pairing 	

D. 	
 Require a promoter and RNA polymerase 	

B. 	
 Are regulated by homeobox genes 	

E. 	
 Are created from an ordered sequence of amino acids 	

C. 	
 Require DNA polymerase 	

 	

 
31.	 The DNA template ATGCGTTA is transcribed into an RNA strand with the sequence:   
A. 	
 TACGCAAT 	

D. 	
 AUGCGAAU 	

B. 	
 UAACGCAU 	

E. 	
 AUGCGUUA 	

C. 	
 UACGCAAU 	

 	

 
32.	 In transcription, one DNA strand is transcribed into a(n) _____ RNA strand, which is translated into protein.  
A. 	
 Ribosomal 	

D. 	
 Anticodon 	

B. 	
 TRNA 	

E. 	
 Thymine rich 	

C. 	
 Messenger 	

 	

 
33.	 A(n) _______ molecule carries amino acids to the ribosomes where they are joined to form a polypeptide.   
A. 	
 MtDNA 	

D. 	
 TRNA 	

B. 	
 RRNA 	

E. 	
 SiRNA 	

C. 	
 MRNA 	

 	

 
34.	 A codon consists of 3 consecutive:   
A. 	
 DNA bases 	

D. 	
 MRNA bases 	

B. 	
 Amino acids 	

E. 	
 Proteins 	

C. 	
 TRNA bases 	

 	

 
35.	 After transcription and before translation, eukaryotic mRNA is modified by adding:   
A. 	
 TRNAs and amino acids 	

D. 	
 Ribosomes and tRNAs 	

B. 	
 Amino acids and a poly-A tail 	

E. 	
 Mutations 	

C. 	
 A cap of modified nucleotides and a poly-A tail 	

 	

 
36.	 B is an intron between two exons A and C. Which representation best describes how this region of mRNA will appear after it is transcribed and processed by a spliceosome?   
A. 	
 A-C 	

D. 	
 A-B-C 	

B. 	
 A-B 	

E. 	
 B only 	

C. 	
 B-C 	

 	

 
37.	 The linear order of amino acids in a polypeptide is the _______ structure of a protein.   
A. 	
 Primary 	

D. 	
 Quaternary 	

B. 	
 Secondary 	

E. 	
 Chaperone 	

C. 	
 Tertiary 	

 	

 
38.	 Spongiform encephalopathies, such as mad cow disease, are caused by:   
A. 	
 A degenerate genetic code 	

D. 	
 Misfolded proteins 	

B. 	
 Triplet repeats in genes 	

E. 	
 Lack of amino acids in the diet 	

C. 	
 Lack of intron splicing 	

 	

 
39.	 Which of the following observations about the genetic code most supports the hypothesis that life evolved from a common ancestor?   
A. 	
 It is a triplet code 	

C. 	
 It is degenerate 	

B. 	
 It is universal 	

D. 	
 Some cells translate the stop codon as a 21st amino acid 	

	
 
40.	 _______ tag misfolded proteins for refolding or degredation into amino acids.   
A. 	
 Chaperones 	

D. 	
 Proteosomes 	

B. 	
 Folding catalysts 	

E. 	
 Ubiquitin molecules 	

C. 	
 Folding sensors 	

 	

 
41.	 _______ are tunnel-like structures that degrade misfolded proteins into amino acids.   
A. 	
 Chaperones 	

D. 	
 Proteosomes 	

B. 	
 Folding catalysts 	

E. 	
 Ubiquitin molecules 	

C. 	
 Folding sensors 	

 	

 
42.	 Proteomics refers to the study of all proteins made by a cell or organism.   
A. 	
 True 	

B. 	
 False 	

	
 
43.	 A coding portion of a gene is called a(n):   
A. 	
 Intron 	

D. 	
 Promoter 	

B. 	
 Domain 	

E. 	
 Acetyl group 	

C. 	
 Exon 	

 	

 
44.	 Multiple proteins can be produced from a single gene by:   
A. 	
 Intron shuffling 	

D. 	
 Production of pseudogenes 	

B. 	
 Alternate splicing of exons 	

E. 	
 Chromatin remodeling 	

C. 	
 Chain switching 	

 	

 
45.	 A chemical or physical agent that causes mutations is called a:   
A. 	
 Mutator 	

D. 	
 Mutagen 	

B. 	
 Tautomer 	

E. 	
 Triplet codon 	

C. 	
 Teratomer 	

 	

 
46.	 Estimates of spontaneous or de novo, mutation rates are made using dominant disorders because:   
A. 	
 They will never be detected 	

D. 	
 They can be identified by DNA sequencing 	

B. 	
 They will not affect offspring 	

E. 	
 All of these 	

C. 	
 They are often obvious in the phenotype 	

 	

 
47.	 Mutational hot spots occur most often where the DNA is:   
A. 	
 Unwound and stretched 	

D. 	
 Bound by RNA polymerase 	

B. 	
 Repetitive or symmetrical 	

E. 	
 Replaced with RNA in the genome 	

C. 	
 Highly coiled 	

 	

 
48.	 Palindrome sequences are often found at mutation hotspots. Which of the following is a palindrome?   
A. 	
 AAAATTTT 	

D. 	
 GATCGATC 	

B. 	
 ATATGCGC 	

E. 	
 UCGUGGCCUU 	

C. 	
 GATCCTAG 	

 	

 
49.	 A germline mutation:   
A. 	
 Occurs only in microbes 	

D. 	
 Are expressed only in embryos 	

B. 	
 Affects a particular subset of cells 	

E. 	
 Occurs in bacteria or viruses 	

C. 	
 Affects all cells of an individual 	

 	

 
50.	 A somatic mutation:   
A. 	
 Occurs only in microbes 	

D. 	
 Are expressed only in embryos 	

B. 	
 Affects a particular subset of cells 	

E. 	
 Affects sleep cycles 	

C. 	
 Affects all cells of an individual 	

 	

 
51.	 A point mutation alters:   
A. 	
 A single base 	

D. 	
 A chromosome arm 	

B. 	
 3 bases 	

E. 	
 Sticky ends 	

C. 	
 An amino acid 	

 	

 
52.	 Which of the following is a transition mutation?   
A. 	
 ACC  CCA 	

C. 	
 GG  CC 	

B. 	
 A  G 	

D. 	
 A  T 	

	
 
53.	 Which type of mutation substitutes one amino acid for another?   
A. 	
 Nonsense 	

D. 	
 Presence 	

B. 	
 Missense 	

E. 	
 All of these 	

C. 	
 Sense 	

 	

 
54.	 A mutation that changes the codon GAA to UAA (stop) is a _______ mutation.   
A. 	
 Missense 	

D. 	
 Truncation 	

B. 	
 Nonsense 	

E. 	
 Viral 	

C. 	
 Frameshift 	

 	

 
55.	 Which addition to a DNA sequence would not cause a frameshift mutation?   
A. 	
 T 	

D. 	
 GGCT 	

B. 	
 GC 	

E. 	
 AAAAA 	

C. 	
 GCT 	

 	

 
56.	 Transposable elements:   
A. 	
 Are found only in viruses 	

D. 	
 Are rare 	

B. 	
 Cannot mutate 	

E. 	
 Are deleted in meiosis 	

C. 	
 Move 	

 	

 
57.	 A mutation expressed only under certain conditions is:   
A. 	
 Germinal 	

D. 	
 Conditional 	

B. 	
 Somatic 	

E. 	
 The worst kind 	

C. 	
De novo 	

 	

 
58.	 Ultraviolet light damages DNA by causing:   
A. 	
 Purine rings 	

D. 	
 Radioactivity 	

B. 	
 Strand breaks 	

E. 	
 Night blindness 	

C. 	
 Pyrimidine dimers 	

 	

 
59.	 DNA damage in bacteria caused by ultraviolet light can usually be repaired by:   
A. 	
 DNA ligase 	

D. 	
 DNA replication 	

B. 	
 Photoreactivation 	

E. 	
 Chromatin remodeling 	

C. 	
 Ionizing radiation 	

 	

 
60.	 Individuals with _______ develop numerous skin cancers when exposed to sunlight.   
A. 	
 Ataxia tetangiectasis 	

D. 	
 Xeroderma pigmentosum 	

B. 	
 Cockayne syndrome 	

E. 	
 Hereditary nonpolyposis colon cancer 	

C. 	
 Werner syndrome 	

 	

 
61.	 A mutation can:   
A. 	
 Prevent the production of a protein 	

D. 	
 Slow the production of a protein 	

B. 	
 Cause a protein to be overexpressed 	

E. 	
 All of these 	

C. 	
 Impair a protein's function 	

 	

 
62.	 The best test of the mutagenic potential of a substance would be:   
A. 	
 A family pedigree 	

C. 	
 Beryllium screening 	

B. 	
 The Ames test 	

D. 	
 Karyotype analysis 	

	
 
63.	 Gene expression profiles may be useful in predicting disease progression and responsiveness to therapy.   
A. 	
 True 	

B. 	
 False 	

	
 
64.	 Which of the following neurologic conditions can be both inherited and acquired?   
A. 	
 Alzheimer's disease 	

C. 	
 Fatal familial insomnia 	

B. 	
 Creutzfeldt-Jakob disease 	

D. 	
 Huntington's disease 	

	
 
65.	 Some mutations may not affect the phenotype.   
A. 	
 True 	

B. 	
 False 	

	
 
66.	 A missense mutation causes sickle cell anemia by:   
A. 	
 Altering the protein's code that changes its shape and affecting its function 	

D. 	
 Inverting a segment of a chromosome 	

B. 	
 Changing a triplet codon that does not affect the reading frame 	

E. 	
 Creating a ring chromosome 	

C. 	
 Altering an intron splicing site so that an entire exon is deleted 	

 	

 
67.	 About what percent of the human genome actually encodes proteins?   
A. 	
 0.5 	

D. 	
 10 	

B. 	
 1.5 	

E. 	
 100 	

C. 	
 5.0 	

 	

 
68.	 DNA is able to replicate as quickly as it does because it has many   
A. 	
 replication forks. 	

C. 	
 chromosomes. 	

B. 	
 replication spoons. 	

D. 	
 genes. 	

	
 
69.	 The nitrogenous base that is in RNA but not in DNA is  
 
A. 	
 thymine. 	

D. 	
 urea. 	

B. 	
 thiamine. 	

E. 	
 adenine. 	

C. 	
 uracil. 	

 	

 
70.	 There are __ different sequences of codons possible in the genetic code.   
A. 	
 3 	

D. 	
 64 	

B. 	
 4 	

E. 	
 46 	

C. 	
 16 	

 	

 
71.	 A mutation that adds one or two bases to a gene disrupts the   
A. 	
 replicating frame. 	

C. 	
 genetic code. 	

B. 	
 intron index. 	

D. 	
 reading frame. 	

	
 
72.	 Chromatin remodeling can block ________ and microRNA binding can block _______.   
A. 	
 transcription; translation 	

D. 	
 DNA replication; DNA repair 	

B. 	
 translation; transcription 	

E. 	
 acetylation; phosphorylation 	

C. 	
 synthesis of tRNAs; synthesis of rRNAs 	

 	

 
73.	 A germline mutation passes from generation to generation because it occurs during the DNA replication before 
A. 	
 mitosis. 	

D. 	
 puberty. 	

B. 	
 meiosis. 	

E. 	
 RNA replication. 	

C. 	
 fertilization. 	

 	

 
74.	 In Ehlers-Danlos syndrome type 1, collagen molecules are   
A. 	
 too short. 	

D. 	
 too scarce. 	

B. 	
 missing. 	

E. 	
 too abundant. 	

C. 	
 too long. 	

 	

 
75.	 The type of DNA repair that corrects errors due to oxidative damage by replacing one to five nucleotides is   
A. 	
 mismatch repair. 	

C. 	
 roto-rooter repair. 	

B. 	
 base excision repair. 	

D. 	
 photoreactivation. 	

	

Test 3 10 Key
 
1. C
 
2. C
 
3. A
 
4. D
 
5. A
 
6. D
 
7. C
 
8. A
 
9. B
 
10. B
 
11. C
 
12. B
 
13. B
 
14. B
 
15. A
 
16. C
 
17. B
 
18. B
 
19. C
 
20. A
 
21. B
 
22. B
 
23. B
 
24. C
 
25. A
 
26. E
 
27. A
 
28. C
 
29. C
 
30. A
 
31. C
 
32. C
 
33. D
 
34. D
 
35. C
 
36. A
 
37. A
 
38. D
 
39. B
 
40. E
 
41. D
 
42. A
 
43. C
 
44. B
 
45. D
 
46. C
 
47. B
 
48. C
 
49. C
 
50. B
 
51. A
 
52. B
 
53. B
 
54. B
 
55. C
 
56. C
 
57. D
 
58. C
 
59. B
 
60. D
 
61. E
 
62. B
 
63. A
 
64. B
 
65. A
 
66. A
 
67. B
 
68. A
 
69. C
 
70. D
 
71. D
 
72. A
 
73. B
 
74. C
 
75. B