o 201 e4

Question 1

1. Which of the following statements is/are true about genes?
   a. They exist in different forms.
   b. They contain information to produce particular protein or RNA.
   c. They contain sequences that determine where genes will be expressed.
   d. AOTA

Answer 1

d. AOTA

Question 2

2. Which of the following statements is true?
   a. Exons are retained in the mature mRNAs
   b. Most human genes have fewer introns than exons
   c. Introns are generally found in prokaryotic and eukaryotic genes.
   d. Genes are locations in the chromosomes where the specific protein is expressed by the genome.

Answer 2

a. Exons are retained in the mature mRNAs

Question 3

3. Function of histones (non-verbatim)?
   a. comprises the nucleosome core
   b. composed primarily of acidic AAs
   c. regulates gene expression through covalent modification of C-ter tails.
   d. NOTA

Answer 3

d. NOTA

Question 4

4. Which of the following is true for the euchromatin?
   a. It is a tightly packed type of chromatin
   b. It makes up only 10% of the whole human genome
   c. It actively transcribes DNA to form mRNA
   d. Repeated base sequences found at the ends of the chromosome

Answer 4

c. It actively transcribes DNA to form mRNA

Question 5

5. Why is genomic sequencing other than humans potentially valuable?
   a. Diseases of cellular function can be studied in relatively simpler model systems.
   b. Comparison of genes between different species can allow prediction of disease-causing mutations.
   c. Genes may have similar function in other species, giving us a place to start with functional analysis of similar genes
   d. All of the above

Answer 5

d. All of the above

Question 6

6. The whole genome shotgun sequencing approach used by Celera Genomics depend on which if the following?
   a. rapid sequencing of thousands of randomly cloned fragments
   b. sequencing of random DNA from each chromosome
   c. methodical sequencing of few large cloned fragments
   d. sequencing of intact chromosome

Answer 6

a. rapid sequencing of thousands of randomly cloned fragments

Question 7

7. What is true regarding single nucleotide polymorphisms (SNP)?
   a. An SNP mutation in a gene means that there is more than one allele for that gene.
   b. They may bring about change in an amino acid sequence.
   c. May occur in non-coding regions of genes.
   d. AOTA

Answer 7

d. AOTA

Question 8

8. Which is true regarding personalized genetic medicine?
   a. Deliver the most effective treatment plan
   b. Optimize disease prevention strategies
   c. Reduce treatment-induced complications
   d. AOTA

Answer 8

d. AOTA

Question 9

9. Which of the following statements about DNA methylation is TRUE?
   a. Increased number of CpG dinucleotides during the evolution of vertebrates increases the chances of gene control by changes in exon sequences
   b. DNA is simultaneously methylated and acetylated as a form of genes regulation
   c. Methylation of DNA increases the chance of a gene becoming active
   d. DNA methylation patterns change throughout the development of an embryo to childbirth

Answer 9

d. DNA methylation patterns change throughout the development of an embryo to childbirth

Question 10

10. Which of the following is a characteristic of a transcripitionally active chromatin
    a. Highly condensed
    b. Acetylated histone
    c. Neither
    d. Both

Answer 10

b. Acetylated histone

Question 11

11. As a mesenchymal stem cell undergoes differentiation to terminally differentiated cell, which of the following processes is most likely to happen?
    a. Decrease in methylation of CpG islands and increase in acetylation of histones
    b. Increase in methylation of CpG islands and increase in acetylation of histones
    c. Decrease in methylation of CpG islands and decrease in acetylation of histones
    d. Increase in methylation of CpG islands and decrease in acetylation of histones
12. A certain protein X regulates its own production by

Answer 11

d. Increase in methylation of CpG islands and decrease in acetylation of histones

Question 12

12. A certain protein X regulates its own production by exerting influence on its own pre-mRNA. By binding to its own pre- mRNA, it allows cleavage but not polyadenylation of the pre- mRNA. Which of the following will occur consequently?
    a. Transport to the cytoplasm but no translation
    b. Errors in RNA splicing
    c. Formation of alternative isoforms of the protein
    d. Degradation of the pre-mRNA with exonuclease

Answer 12

d. Degradation of the pre-mRNA with exonuclease

Question 13

13. The fibronectin gene is expressed in hepatocytes and fibroblasts. The pre-mRNAs produced in the 2 cells types both contain the exons EIIIA and EIIIB. In the fibroblast, these 2 exons are present and allow the protein to adhere to cell surfaces. In the hepatocyte, the mRNA does NOT contain these 2 exons, allowing the protein product to circulate in the serum. Which type of control of gene expression is this?
    a. Transcriptional control
    b. mRNA transport
    c. Post-transcriptional control
    d. Translational control

Answer 13

c. Post-transcriptional control

Question 14

14. Peptide hormones exert their influence on gene expression by initially binding to cell surface receptors. Secondary messengers like cAMP can cause a series of events resulting in the binding of CREB to cAMP-response elements in the DNA. Which type of control of gene expression is this?
    a. Epigenetic control
    b. Transcriptional control
    c. Post-transcriptional control
    d. Translational control

Answer 14

b. Transcriptional control

Question 15

15. If the CpG segment just proximal to a promoter of a tumor supressor gene is amplified 100-fold, which of the following is most likely to happen?
    a. Increase in the acetylation of the segment
    b. Increase in protection against tumorigenesis
    c. Deactivation of the MECP2 protein
    d. Increase in the likelihood of developing a tumor

Answer 15

d. Increase in the likelihood of developing a tumor

Question 16

16. Which of the following statements about trans-acting factors is TRUE?
    a. They are base sequences on the same strand of DNA as the gene that they control
    b. They are typically RNA molecules rather than proteins
    c. They may either suppress or activate gene expression
    d. All of the above statements are FALSE

Answer 16

c. They may either suppress or activate gene expression

Question 17

17. The PER protein has been found to regulate the circardian rhythm. It is active at night and broken down in the morning. Its regulation involves phosphorylation which leads to subsequent ubiquitination and degradation. Identify the regulation involved.
    a. Transcriptional control
    b. Post-transcriptional control
    c. Translational control
    d. Post-translational control

Answer 17

d. Post-translational control

Question 18

18. One example of a mechanism by which viruses can cause cancer is the insertion of its genome into the host. An example is the v-src gene of a virus which is identical to the c-src gene in the host genome. Which of the following BEST describes the mechanism by which this particular proto-oncogene becomes an oncogene?
    a. deletion in coding sequence
    b. gene amplification because of loss of normal regulation
    c. point mutation in coding sequence
    d. chromosome rearrangement

Answer 18

b. gene amplification because of loss of normal regulation

Question 19

19. Which of the pre-mRNA modifications occur in the nucleus?
    a. 5’ end capping with methylguanosine
    b. Excision of exons via lariat formation
    c. 3’ end tailing with adenylates
    d. A and C

Answer 19

A and C

Question 20

20. Which of the following is true about the sequence 5’-GTAG-3’ in relation to pre-mRNA processing?
    a. It defines the intron-exon boundary in the primary transcript
    b. It defines the exon-intron boundary in the primary transcript.
    c. It is found on the coding sequence of the DNA.
    d. It is found on the complementary sequence of the DNA.

Answer 20

c. It is found on the coding sequence of the DNA.

Question 21

21. What genetic sequence does the TATA binding protein attach to?
    a. Promoter
    b. Enhancer
    c. Silencer
    d. Operator

Answer 21

a. Promoter

Question 22

22. Which is not true about bacterial RNA polymerase?
    a. A sigma factor is required for RNA polymerase to bind to the promoter region.
    b. Rho-independent termination requires the terminal sequence AAUAAA
    c. RNA polymerase can polymerize mRNA, tRNA and rRNA
    d. A sigma factor is required for the initiation of transcription

Answer 22

b. Rho-independent termination requires the terminal sequence AAUAAA

Question 23

23. Which of the following RNA does not require ranDTP to transport itself to the cytoplasm?
    a. mRNA
    b. tRNA
    c. miRNA
    d. rRNA

Answer 23

a. mRNA

Question 24

24. Which of the following codons codes for an amino acid that has a ringed structure?
    a. UGA
    b. UGG
    c. AUG
    d. UAG

Answer 24

b. UGG

Question 25

25. Which of the following is TRUE of eukaryotic ribosomes? a. 50S + 30S = 70S b. The mRNA facilitates the attachment of small and large ribosomal units simultaneously. c. The attached ribosomes in the ER are actively translating. d. The small ribosomal unit initially attaches to the Shine-Dalgarno sequence of the mRNA.

Answer 25

c. The attached ribosomes in the ER are actively translating.

Question 26

26. Which part of the tRNA do activated amino acids attach to? a. 5’ end b. 3’ end c. D loop d. Anticodon loop

Answer 26

b. 3’ end

Question 27

27. Which of the following statements is false? a. First amino acid in prokaryotic translation is formylated methionine b. Polyadenylate polymerase is anchored to the CPSF c. Activation of amino acid prior to attaching to tRNAs require GTP hydrolysis d. Release factors recognize the codon UAA

Answer 27

a. Activation of amino acid prior to attaching to tRNAs require GTP hydrolysis

Question 28

28. Which of the following is true of nucleotide digestion? a. Initiated by gastric nucleases b. Facilitated by pancreatic nucleotidase c. Occurs in the small intestine and stomach d. End product is nucleosidase

Answer 28

c. Occurs in the small intestine and stomach

Question 29

29. Which of the following statements regarding the regulation of purine biosynthesis is incorrect? a. The reactions after the branch point in AMP and GMP synthesis are subject to feedback inhibition b. AMP, XMP, and GMP are negative feedback regulators of the pathway c. ATP provides energy for GMP production d. ATP and GTP inhibit the rate limiting step of de novo synthesis

Answer 29

b. AMP, XMP, and GMP are negative feedback regulators of the pathway

Question 30

30. Which of the following is incorrect during salvage purine synthesis is incorrect? a. Preformed purine monophosphates are the major precusrsors b. GMP forms Hypoxanthine c. Less ATP is consumed than in de novo sythesis of bases d. defect in APRT causes Lesch-Nyhan Syndrome

Answer 30

d. defect in APRT causes Lesch-Nyhan Syndrome

Question 31

31. Which of the following processes is involved in the formation of deoxyribonucleotides? a. Incorporation of dietary deoxyribose to purine and pyrimidine bases b. Attachment of deoxyribose to preformed bases via phosphoribosyl transferase c. Synthesis of deoxyribose by the PPP d. Reduction of C2 of the 4 different ribonucleotide diphosphate

Answer 31

d. Reduction of C2 of the 4 different ribonucleotide diphosphate

Question 32

32. Which of the following statements is NOT TRUE regarding the catabolism of nucleotides? a. B-aminoisobutyrate is an end product of thymine nucleotide degradation b. B-alanine is the end product of cytosine degradation c. A defect in the adenosine catabolic enzyme leads to severe combined immune deficiency syndrome d. Less severe immunodeficiency may be due to defective pyrimidine nucleoside phosphorylase

Answer 32

b. B-alanine is the end product of cytosine degradation

Question 33

33. What pathway is affected in severe combined immunodeficieny (scid) a. purine synthesis b. purine salvage pathway c. purine catabolism d. pyrimidine degradation

Answer 33

c. purine catabolism

Question 34

34. A defect in the activity of this enzyme will predispose to the development of goiter a. HGPRT b. Xanthine oxidase c. PRPP Synthetase d. A & B only

Answer 34

a. HGPRT

Question 35

35. The replicative DNA polymerase ensures that the correct base pair interacts by which of the following mechanisms? a. Interacting with and recognizing the incoming dNTP b. Accomplishing fast catalysis in the presence of the correct base pair c. Accomplishing slow catalysis in the presence of the correct base pair d. Mechanism still unknown

Answer 35

b. Accomplishing fast catalysis in the presence of the correct base pair

Question 36

36. The _____________ groove is less information-rich; ____________ makes use of this to carry out its primary function a. Major; DNA polymerase b. Minor; DNA polymerase c. Major; exonuclease d. Minor; exonuclease e. Major + Minor; DNA P. + exonuclease v

Answer 36

b. Minor; DNA polymerase

Question 37

37. Lysine and arginine are part of the O-helix of the DNA polymerase, along with metal cations. Which statement is not true? a. Lysine, arginine, and metal cations are all positively charged b. Metal cations interact with and help position the alpha, beta, and gamma phosphates c. Lysine is critical in making stacking interactions with incoming dNTP d. Lysine and arginine interact with and help position the alpha, beta, and gamma phosphates

Answer 37

b. Metal cations interact with and help position the alpha, beta, and gamma phosphates

Question 38

38. Proofreading exonucleases are critical in the fidelity of DNA synthesis. Which statement/s is/are incorrect? a. The proofreading exonucleases can be part of the same polypeptide chain as the DNA polymerase b. The proofreading exonucleases increases the fidelity of DNA synthesis about 100 fold c. The proofreading exonucleases degrades short stranded DNA starting at the 5' end d. The proofreading exonucleases degrades short stranded DNA starting at the 3' end

Answer 38

c. The proofreading exonucleases degrades short stranded DNA starting at the 5' end

Question 39

39. Based on the structural properties of replicative DNA helicase, which of the statements is supported by these structural properties? a. The replicative DNA helicase initiates when binded to single stranded DNA not double stranded DNA. b. The replicative DNA helicase initiates when binded to double stranded DNA c. All 6 subunits are in the same nucleotide bound or unbound state at the same time d. ATP hydrolysis is the key step in replicative DNA helicase translocation along the DNA strand.

Answer 39

a. The replicative DNA helicase initiates when binded to single stranded DNA not double stranded DNA.

Question 40

40. Select all that characterize SSB protein a. Prevalent in both leading strand and lagging strand template b. Promote primase activity c. Prevent reannealing between leading strand template and lagging strand template d. Prevent annealing between complementary bases of leading strand template

Answer 40

b. Promote primase activity

Question 41

41. Which of the following statements about the sliding DNA clamp is FALSE? a. It is a multimeric protein b. It enhances the processivity of DNA polymerase c. It encircles only single-stranded DNA d. It helps recruit and maintain other DNA replication enzymes to the replication fork

Answer 41

c. It encircles only single-stranded DNA

Question 42

42. Origin of replication: a. The primer:template junction to which the DNA polymerase III holoenzyme binds b. The genetic locus required to initiate replication c. The physical site where DNA is initially unwound and DNA synthesis is initiated d. The region of DNA that one DNA polymerase replicates

Answer 42

c. The physical site where DNA is initially unwound and DNA synthesis is initiated

Question 43

43. Which of the ff does not contribute to the accuracy of DNA polymerase? a. Mismatch Repair b. 5' -> 3' endonuckease proofreading c. 3' -> 5' endonuclease proofreading d. All of the above

Answer 43

b. 5' -> 3' endonuckease proofreading

Question 44

44. Which statement is/are FALSE regarding MutS binding to DNA and function? a. MutS scans 700 base pairs per binding event b. MutS scans only double stranded DNA c. MutS scanning is nondirectional d. MutS scanning requires energy e. All of the above

Answer 44

b. MutS scans only double stranded DNA

Question 45

45. Which of the following statements best describes hemimethylated DNAs in E. coli cells? a. The lagging strand is methylated while the leading strand is unmethylated b. The leadung strand is methylated while the lagging strand is methylated c. The parental strand is methylated while the newly synthesized strand is unmethylated d. The newly synthesized strand is methylated while the parental strand is unmyelinated

Answer 45

c. The parental strand is methylated while the newly synthesized strand is unmethylated

Question 46

46. Which of the following is true regarding genetic variations and resulting traits? a. That different genetic variations can manifest into different health conditions b. That different genetic variations always result to observable traits c. That different genetic variations cannot result to physiological differences d. That different genetic variations cannit manifest similar health conditions

Answer 46

a. That different genetic variations can manifest into different health conditions

Question 47

47. When is DNA testing LEAST applicable in real life? a. Identifying a dead body b. Determining relationship of 2 individuals c. Determine one’s predisposition to a disease d. Monitor a condition of a disease in a person

Answer 47

d. Monitor a condition of a disease in a person

Question 48

48. Which is true about genetic testing? a. That genes sufficiently associated with a disease or condition are definitely causal to those conditions b. That genes sufficiently associated with a disease or condition are definitely effects of those conditions c. That genes sufficiently associated with a disease or condition can be used for the testing of these conditions d. That genes sufficiently associated can be used for the testing of mendelian diseases but not complex diseases, such as cancer

Answer 48

c. That genes sufficiently associated with a disease or condition can be used for the testing of these conditions

Question 49

49. In nucleic acid isolation and (forgot the term), which is true? a. organic method produces lower yield b. silica method can be used for both RNA and DNA c. a combination of both is not possible

Answer 49

b. silica method can be used for both RNA and DNA

Question 50

50. Which of the following is false regarding the polymerase chain reaction (PCR)? a. It can be used to make a copy of the whole human genome b. The mix is composed of a template, buffer, primer, and DNTPs. c. The initial increase in temperature is for denturation d. The lower temperatures are for the polymerase to attach to the daughter strand

Answer 50

b. The mix is composed of a template, buffer, primer, and DNTPs.

Question 51

51. What is false about quantitative PCR? a. It can monitor physiologic conditions of animals b. It can detect dna/rna containing pathogens c. It uses tech under the premise that fluorescence is inversely related to amplification d. It uses process of determining temperatures of amplified products to differentiate variants of sequences

Answer 51

c. It uses tech under the premise that fluorescence is inversely related to amplification

Question 52

52. Which is not true about genome testing? a. Whole Genetic testing is expensive, but rapidly getting cheaper b. No prior knowledge is not needed when doing genome sequencing c. Targetted Genome sequencing is the cheapest, but has no clinical significance d. Exome genome sequencing is less expensive compared to whole genome sequencing

Answer 52

c. Targetted Genome sequencing is the cheapest, but has no clinical significance

Question 53

53. Which of the following is the MOST LIKELY advantage of gene sequencing over microarray? a. Investigation of SNPs affecting regulatory regions b. Investigation of SNPs affecting coding regions c. Investigation of previously unknown SNPs affecting regulatory regions d. Investigation of known SNPs affecting coding regions

Answer 53

d. Investigation of known SNPs affecting coding regions

Question 54

54. Which of the following statements is FALSE about protein-based assays? a. They typically use specific antibodies as probes or detectors b. Enzyme-linked immunoassays can be used for diagnosis, monitoring of treatment, and as confirmatory tests c. Lateral flow assays may be used to detect pathogens, but not human proteins d. Immunohistochemistry offers the advantage of cellular/tissue localization of expressed proteins

Answer 54

c. Lateral flow assays may be used to detect pathogens, but not human proteins

Question 55

55. Which of the following assays would be the MOST APPROPRIATE in the blood testing of pathogens or reactive antibodies in areas of disease outbreak without electricity? a. Quantitative PCR b. DNA sequencing c. Lateral flow assays d. Immunohistochemistry

Answer 55

c. Lateral flow assays

Question 56

56. Which of the following techniques offers the BEST method to determine the presence of a mutation in a patient suspected of having a disease? a. qPCR b. Gene Sequencing c. Immunoassay d. Immunohistochemistry

Answer 56

b. Gene Sequencing

Question 57

57. A pedigree is a useful tool in genetics because: a. It informs the patient of their family history. b. It allows for analysis of similar conditions in relatives. c. It allows the patient to be aware of potential health problems. d. All of the above

Answer 57

b. It allows for analysis of similar conditions in relatives.

Question 58

58. In autosomal recessive disorders: a. Males and females are equally affected b. Parents of the affected child are symptomatic carriers of the allele c. Recurrence rate is 1 in 4 d. A and C are correct

Answer 58

d. A and C are correct

Question 59

59. Characteristics of autosomal dominant inheritance include: a. Male to male transmission occurs b. Male to female transmission occurs c. Males can have unaffected daughters d. All are correct

Answer 59

d. All are correct

Question 60

60. Which of the following statements is/are TRUE for X-linked recessive inheritance? a. Heterozygous females may manifest the disorder b. No father to son transmission c. Carrier females have 50% chance of having an asymptomatic carrier daughter d. All of the above

Answer 60

d. All of the above

Question 61

61. Imprinting refers to: a. A parent of origin effect in which modification of a gene allows it to be expressed differently b. Inhibition of imprinted gene which prevents gene expression c. Conditions such as Prader Willi Syndrome and Angelman Syndrome d. AOTA

Answer 61

d. AOTA

Question 62

62. Confounding variables for the expression of genetic inheritance include: a. Small family size b. Non-paternity c. Sex-influenced or sex-limited inheritance d. All of the above

Answer 62

d. All of the above

Question 63

63. Which of the following statements are true regarding mitochondrial disorders? a. Males and females are equally affected often in multiple generations b. The father is the one responsible for transmission of disease c. There is high variability in clinical expressivity d. All of the above e. Only A and C

Answer 63

e. Only A and C

Question 64

64. Which of the following condition/s shows a non- Mendelian pattern of inheritance? a. Triple expansion disorder b. Mitochondrial disorder c. Genomic imprinting disorder d. AOTA

Answer 64

d. AOTA

Question 65

65. Which of the following describes triple repeat expansion? a. composed of repeats of three nucleotides b. family members have the same number of repeats c. the number of repeats increases through the generations d. A and C

Answer 65

d. A and C

Question 66

66. Which is true of mitochondrial disorders? a. Organs with High Energy use are more affected when there is mutant mitochondria b. Most diseases caused by malfunction of the mitochondria follow typical mitochondrion pattern and not mendelian inheritance pattern. c. Heteroplasmy refers to having a mix of normal and mutant mitochondrion genetic material in a cell

Answer 66

d. All of the above are correct

Question 67

67. W/c of the following statements about genograms is true a. A relationship line is a horizontal line between 2 partners b. The sibship line is a horizontal line connecting brothers and sisters c. The line of descent is a Vertical bridge connecting the horizontal sibship line to the horizontal relationship line d. AOTA

Answer 67

d. AOTA

Question 68

68. Which of the following statements about polygenic obesity is/are incorrect? a. It is due to the interaction of multiple genes and environmental factors b. Genes involved in polygenic obesity are implicated in body weight regulation c. It is rarely observed in the population d. All of the above

Answer 68

c. It is rarely observed in the population

Question 69

69. W/c of the following about monogenic obesity is true a. It is caused by mutation of multiple genes b. Most genes associated with monogenic obesity are involved in central nervous regulation of hunger and satiety c. It is the common type of obesity in the population d. AOTA

Answer 69

c. It is the common type of obesity in the population

Question 70

70. Which is true of syndromic obesity? a. Due to mutations or chromosome abnormalities b. Obesity in genetic disorders which are also associated with intellectual abnormalities, physical dysfunctionalities, and some neuroendocrine abnormalities c. Genes in syndromic obesity are associated with CNS appetite control and support hyperphagia as cause of obesity d. All of the above

Answer 70

b. Obesity in genetic disorders which are also associated with intellectual abnormalities, physical dysfunctionalities, and some neuroendocrine abnormalities

Question 71

71. Homozygous mutation of the leptin gene will most likely lead to: a. Impaired satiety b. Food withdrawal c. Decreased appetite d. B and C

Answer 71

a. Impaired satiety

Question 72

72. Which of the following best demonstrates epigenetic control in obesity? a. Disruption of methylation in agouti gene b. Missense mutation in FTO gene c. Increased methylation in IGF1 gene d. A and C only

Answer 72

d. A and C only

Question 73

73. Which of the following helps explain why members of the same family tend to be obese? a. Genetic similarity b. Physical Activity c. Food choices d. AOTA

Answer 73

d. AOTA

Question 74

For the ff questions refer to the choices: a. Ribose 5-PO4 + ATP -> PRPP +AMP b. Hypoxanthine -> Xanthine -> Uric Acid c. Folate-> dihydrofolate -> tetrahydrofolate d. dUMP -> TMP e. Adenosine + water -> inosine + NH3 74. Allopurinol

Answer 74

Hypoxanthine -> Xanthine -> Uric Acid

Question 75

For the ff questions refer to the choices: a. Ribose 5-PO4 + ATP -> PRPP +AMP b. Hypoxanthine -> Xanthine -> Uric Acid c. Folate-> dihydrofolate -> tetrahydrofolate d. dUMP -> TMP e. Adenosine + water -> inosine + NH3 75. 5-fluorouracil & its metabolite 5f-dUMP

Answer 75

d. dUMP -> TMP

Question 76

For the ff questions refer to the choices: a. Ribose 5-PO4 + ATP -> PRPP +AMP b. Hypoxanthine -> Xanthine -> Uric Acid c. Folate-> dihydrofolate -> tetrahydrofolate d. dUMP -> TMP e. Adenosine + water -> inosine + NH3 76. Methotrexate

Answer 76

c. Folate-> dihydrofolate -> tetrahydrofolate

Question 77

77. Which of the following statements is/are true? a. About 10% of the human genome encodes protein sequences b. Majority of the human genome are transposable DNA Elements c. The number of sequence of simple repeats in the human genome does not vary that much between species d. AOTA

Answer 77

Majority of the human genome are transposable DNA Elements

Question 78

78. Which of the following best describes a genome? a. All of the DNA in a cell b. All of the genes in an organism c. All of the chromosomes inherited from the father d. All of the RNA and protein synthesized by the organism

Answer 78

a. All of the DNA in a cell

Question 79

79. Which of the specialized sequences in chromosomes is/are important for replication? a. Replication origin b. Centromeres c. Telomeres d. A and C only

Answer 79

d. A and C only

Question 80

80. What is the fundamental repeating unit of organization in a eukaryotic chromosome? a. Histone core b. Nucleosome c. 30-nm fiber d. Sister chromatid

Answer 80

b. Nucleosome

Question 81

81. An ion transporter gene which encodes a protein normally expressed in the respiratory and digestive tracts is mutated in cystic fibrosis. Individuals homozygous with this mutation died at very early ages prior to the advent of advanced medical intervention. Despite this, the mutation exists at relatively high frequency in populations of European descent. One potential explanation us that the heterozygotes for such mutations may be relatively immune to the lethal effects of diseases such as typhoid fever. Which of the following statements is the most accurate? a. The cystic fibrosis mutation is a beneficial mutation b. The mutation is neutral c. The mutation is lethal d. AOTA

Answer 81

c. The mutation is lethal

Question 82

82. In which of the following cell/stages of development would there be the smallest degree of DNA Methylation a. Sperm cell b. Adult hepatocyte c. Somatic cell d. Progenitor germ cell

Answer 82

d. Progenitor germ cell

Question 83

83. Which of the following mechanisms of gene regulation is responsible for the ability of an individual to form antibodies to a multitude of antigens a. DNA rearrangement b. Gene amplification c. RNA Editing d. Alternate splicing

Answer 83

a. DNA rearrangement

Question 84

84. The concentration of milk protein casein mRNA in rat mammary tissue is controlled by the hormone prolactin. When prolactin is present, the concentration of mRNA is 30,000 molecules per cell, up from 100 when the hormone is absent. The presence of prolactin increases the synthesis of casein mRNA threshold. Most of the increases in concentration of casein mRNA results from an enormous increase in its stability. What are the two mechanisms of gene regulation demonstrated here? a. Epigenetic and transcriptional b. Transcriptional and translational c. RNA transport and post-transcriptional d. Transcriptional and post-transcriptional

Answer 84

b. Transcriptional and translational

Question 85

85. Which of the following statements about prokaryotic and eukaryotic polycistronic genes is true? a. Each of the prokaryotic cistron does not have its own promoter sequence which each if the eukaryotic cistron has. b. Prokaryotic polycistronic transcripts do not have UTRs while eukaryotic polycistronic transcripts have. c. Prokaryotic polycistronic transcripts are translated into one long polupeptide which are then cleaved into separate proteins, while eukaryotic polycistronic transcripts are cleaved into separate cistrons before translation. d. Prokaryotic polycistronic genes can have transcription and translation occurring simultaneously, while eukaryotic polycistronic genes transcription and translation are temporarily separated

Answer 85

d. Prokaryotic polycistronic genes can have transcription and translation occurring simultaneously, while eukaryotic polycistronic genes transcription and translation are temporarily separated

Question 86

86. Which of the following is false? a. Genes can be located on both strands of the DNA b. Genes that overlap each other have to be on the same DNA strand c. Genes that do not overlap can be found in both the same DNA strand and the opposite strand d. Genes on the same DNA strand can be convergent.

Answer 86

d. Genes on the same DNA strand can be convergent.

Question 87

87. How many GTP hydrolysis are needed to translate a 5-amino acid length neuropeptide? a. 12 b. 13 c. 14 d. 15

Answer 87

b. 13

Question 88

88. Which of the following happens upon failure to cap the 5’ end of the pre-mRNA? a. Failure to excise the most proximal intron b. Failure to cleave 3’ end a few bases after AAUAAA signal c. Failure to polyadenylate 3’ end d. Failure to protect against 3’ exonuclease

Answer 88

a. Failure to excise the most proximal intron

Question 89

89. Which of the ff is true? a. The more complex the organism, the more genes it has. b. The more genes an organism has, the bigger the genome size. c. The bigger the genome size, the more protein coding sequence it has d. NOTA

Answer 89

d. NOTA

Question 90

90. Which of the ff is not a biological role of nucleotides? a. Coenzyme in lipid biosynthesis b. Secondary signaling molecule c. Components of protein d. Source of cellular energy

Answer 90

c. Components of protein

Question 91

91. Which of the following is false regarding the de novo biosynthesis of nucleotides? a. The purine ring is built from a molecule of PRPP b. Glutamine is utilized in both purine and pyrimidine synthesis c. Glutamine amidotransferase catalyzes the committed step in the purine pathway d. Carbamoyl phosphate synthetase II catalyzes the committed step in pyrimidine synthesis. 92. In nick-directed mismatch

Answer 91

d. Carbamoyl phosphate synthetase II catalyzes the committed step in pyrimidine synthesis.

Question 92

92. In nick-directed mismatch repair that occurs in organisms other than E.coli, MutL, and not MutM, nicks DNA. Which of the ff statements is not true about the regulation of MutL endonuclease activity? a. MutS binds MutL after detecting a mismatch b. MutL cuts at GATC sequences c. ADP-bound MutL is active as an endonuclease d. ATP-bound MutL is inactive as an endonuclease

Answer 92

b. MutL cuts at GATC sequences

Question 93

93. In nick directed repair that occurs in organisms other than E.coli, the directionality of the sliding clamp determines which strand for MutL to cut. Which of the following statements regarding sliding clamps and mismatch repair are true? a. The sliding clamp is typically found at a primer template junction during replication b. In the presence of a mismatch, MutL binds to the side of the sliding clamp that faces the direction of new DNA synthesis for the nascent strand of DNA c. In the presence of a mismatch, MutL binds to the side of the sliding clamp that faces the opposite direction of new DNA synthesis for the nascent strand of DNA d. A and B e. A and C

Answer 93

d. A and B

Question 94

94. Which of the ff conditions would RNA testing be least helpful? a. In cases where a noncoding spliced mRNA variant is suspected to be involved. b. In cases where a non coding RNA such as miRNA, is involved c. In cases wherein a post-translational variant of protein is involved d. In cases wherein a variable regulatory region of DNA producing miRNA is involved

Answer 94

c. In cases wherein a post-translational variant of protein is involved

Question 95

95. Which of the ff statements about DNA microarrays is true? a. Microarrays can investigate several genomic variants at a single assay but is limited to the protein coding region b. Microarray probes are typically targeting large genomic changes and not SNPs c. Because of its limitations in using probes to variants should be previously known, this technology is not capable of discovering new genetic associations to disease. d. Microarray findings are being used in genome-wide association studies to determine the association of genomic variants to conditions using large population sizes.

Answer 95

d. Microarray findings are being used in genome-wide association studies to determine the association of genomic variants to conditions using large population sizes.

Question 96

96. Which of the ff describes multifactorial inheritance pattern? a. Only males are affected more severely b. No clear pattern exists c. Demonstrates no generation skipping d. AOTA

Answer 96

b. No clear pattern exists

Question 97

97. Which of the following statements about the thrifty gene hypothesis is true? a. Obesity is due to a mismatch in today’s food abundant environment and the energy-thrifty genes we inherited from our ancestors b. Thrifty genes enabled our ancestors to efficiently deposit fat during periods of food abundance in order to provide for periods of food shortage c. The thrifty gene are advantageous to both modern and ancient societies d. A and B

Answer 97

d. A and B

Question 98

98. Which of the ff statements about fat mass and FTO gene is true? a. Variants of this gene is associated with elevated body mass index b. Variations in this gene associated with obesity can be found in its introns c. Variants of this gene by itself only has a small effect on phenotype d. AOTA

Answer 98

d. AOTA

Question 99

99. Which of the ff statements about MC4R gene is incorrect? a. The protein it encodes is mainly found in the hypothalamus b. Mutation in this gene can cause monogenic obesity c. It encodes a protein that is activated to signal the increase in food intake d. A and C

Answer 99

d. A and C

Question 100

100. Which of the ff statements about the leptin/melanocortin pathways is incorrect? a. Binding of leptin to the receptor leads to alpha MSH activating MC4R, inducing a hunger signal b. This pathway plays a major role in energy intake and expenditure c. POMC undergoes post transcriptional processing, the products of which include MSH d. AOTA

Answer 100

a. Binding of leptin to the receptor leads to alpha MSH activating MC4R, inducing a hunger signal

Question 101

101. Which of the ff environmental factors modulate the risk of polygenic obesity? a. Physical activity b. Diet c. Gender d. AOTA

Answer 101

d. AOTA

Question 102

102. Which of the following genes is associated with monogenic obesity? a. Leptin receptor b. POMC c. PCSK1 d. AOTA

Answer 102

d. AOTA