Quiz Medical Genetics

Medical Genetics 14Mar2009

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1 – Genetics Primer

1) Which of the following is a variant form of a gene, which has a different DNA

sequence and therefore produces a different product?

a) Gene

b) Allele

c) Locus

d) Genotype

e) Phenotype

2) Which of the following is a continuous DNA molecule with associated proteins that

carries genetic information in cells?

a) Genome

b) Chromosome

c) Mitosis

d) Meiosis

e) Locus

3) Which of the following means having only one copy of a gene, such as X-linked genes

in XY males?

a) Diploid

b) Haploid

c) Homozygous

d) Heterozygous

e) Hemizygous

4) Polymorphism describes an allele of a gene that is present in greater than what

percentage of a population, and has no easily discerned effect on phenotype of the

organism?

a) 99%

b) 75%

c) 50%

d) 25%

e) 1%

5) How many autosomes exist for humans?

a) 1

b) 22

c) 23

d) 44

e) 46

6) Sister chromatids attach to the centromere during which phase of mitosis?

a) Prophase

b) Metaphase

c) Anaphase

d) Telophase

e) None of the above

7) What chromosome is the !-globin chain of hemoglobin (Hb) on?

a) 1

b) 11

c) 13



d) 21

e) 23

8) Which of the following is true for carriers of sickle cell anemia?

a) Have sickle hemoglobin (HbS) but no anemia

b) Have normal hemoglobin (HbA) but no anemia

c) Have normal hemoglobin (HbA) and sickle hemoglobin (HbS) but no anemia

d) Have sickle hemoglobin (HbS) and have anemia

e) Have normal hemoglobin (HbA) and have anemia

f) Have normal hemoglobin (HbA), sickle hemoglobin (HbS) and have anemia

9) Most photographs of chromosomes are taken in what phase, which contains twice as

much DNA as do chromosomes in the majority of the cell cycle?

a) Prophase

b) Metaphase

c) Anaphase

d) Telophase


Match the following descriptions with the chromosomal term:

10) Centromere is near one end; short arms (p) are very small a) Metacentric

11) Centromere is offset from center; arms are of different lengths b) Submetacentric

12) Centromere is near the center; arms are of nearly equal length c) Acrocentric

13) If one chromosome had two particular alleles at two different loci (A and B) and

another had different alleles at the same loci (a and b), which of the following are

possible with crossing over (which is more likely with increased gene distance)?

a) A and B or a and b

b) A and a or B and b

c) A and b or B and a

d) None of the above

14) Up to what percentage of all pregnancies result in the birth of a child with a

significant genetic or birth defect?

a) 9%

b) 7%

c) 5%

d) 3%

e) 1%

15) What is the recurrence risk for an autosomal dominant disorder?

a) 0%

b) 25%

c) 50%

d) 75%

e) 100%

2 –Introduction To DNA Technology

1.1) Which of the following advances in DNA technology has made it possible to

produce insulin and human growth factor?

a) Ability to cut, modify, reassemble, and analyze DNA



b) Ability to select, characterize, mutate in a pre-determined manner, and even

synthesize individual genes

c) Ability to clone and express individual genes to produce the proteins they

encode in large amounts

d) Ability to determine and locate the gene mutations responsible for genetic

diseases

e) Ability to diagnosis sufferers and carriers of genetic diseases

f) Ability to plan future therapies that involve manipulation or replacement of

genes

1.2) Which of the following allows a segment of DNA to be amplified from down to one

cell into millions of copies in a few hours?

a) DNA purification and enzymes

b) Reverse transcription of RNA

c) Exploitation of base-pairing specificity in hybridization techniques

d) The development and manipulation of vectors and vectored host cells

e) The development of the polymerase chain reaction

2.1) Which of the following is most likely a restriction site sequence?

a) 5’ GAATTC, 3’ CTTAAG

b) 5’ GAATTC, 3’ CUUAAG

c) 5’ GATCATGCAT, 3’ CTAGTACGTA

d) 5’ GATCATGCAT, 3’ CUAGACGUA

e) 5’ CUAGACGUA, 3’ GATCATGCAT

2.2) Restriction endonucleases (restriction enzymes) are ____ enzymes that cut

(hydrolyze) ____ into smaller fragments.

a) Viral; DNA

b) Viral; RNA

c) Bacterial; DNA

d) Bacterial; RNA

2.3) Restrictions enzymes that create staggered cuts with a special affinity (if reunited)

leave ____ ends, where the ends are ____ stranded.

a) Blunt; Single

b) Blunt; Double

c) Sticky; Single

d) Sticky; Double

2.4) A linker is a short synthetic piece of ____ that can attach to make ____ ends become

____.

a) RNA; Sticky; Blunt

b) RNA; Blunt; Sticky

c) DNA; Sticky; Blunt

d) DNA; Blunt; Sticky

2.5) Which of the following synthesizes a DNA strand that is complementary to an RNA

strand?

a) DNA ligase

b) DNA polymerase

c) Reverse transcriptase

d) Restriction endonuclease



e) Hybridization

2.6) In electrophoresis, DNA is ____ charged and will move toward the anode at a rate

that is ____ proportional to its size.

a) Positively; Directly

b) Positively; Inversely

c) Negatively; Directly

d) Negatively; Inversely

2.7) Hybridization techniques generally involve taking a short single-stranded nucleotide

of known sequence called a ____, and testing it against fragment of DNA for

complementarity.

a) Strip

b) Sticky

c) Blunt

d) Blot

e) Probe

Match the type of testing with the item to be identified:

2.8) Southern blotting a) RNA

2.9) Northern blotting b) Protein

2.10) Western blotting c) DNA

2.11) Using restriction enzymes to find point mutations at the restriction site, called

restriction fragment length polymorphisms (RFLPs), is used for which of the following?

a) Screening a genomic library

b) Diagnosing genetic disease

c) DNA fingerprinting

d) Chromosome walking

e) DNA profiling

2.12) Which of the following methods used in DNA fingerprinting is as accurate as the

traditional fingerprint?

a) Chain termination method

b) Dideoxy method of Sanger

c) Chromosome walking

d) Restriction fragment length polymorphism (RFLPs)

e) Variable number of tandem repeats (VNTRs)

2.13) In chromosome walking, adjacent fragments are identified by probes that:

a) Go from one fragment end to the next

b) Go from a sticky end to a blunt end

c) Go from a blunt end to a sticky end

d) Cut up genomic DNA into smaller more manageable fragments

e) Overlap adjacent fragments

2.14) Which of the following vectors would NOT be used for incorporation of large

eukaryotic genes?

a) Yeast artificial chromosomes (YACs)

b) Bacterial artificial chromosomes (BACs)

c) Cosmids

d) Plasmids



2.15) Which of the following describes the uptake of vector molecules into bacterial

cells?

a) Conjugation

b) Transduction

c) Transformation

d) Translation

e) Transfection

2.16) Cloning vectors that incorporate a polylinker, a region with multiple restriction

sites, have which of the following functions?

a) Gene functions with polylinker, gene functions with insert

b) Gene does not function with polylinker, gene does not function with insert

c) Gene does not function with polylinker, gene functions with insert

d) Gene functions with polylinker, gene does not function with insert

2.17) In an example of the vector pBluescript II SK, cells will have !-galactosidase

activity (break down chromogenic substrate) if a polylinker is intact. This results in a

blue medium. If the polylinker is interrupted, the medium is white. Which of the

following would be chosen in lab for further analysis when using the insertional

inactivation technique?

a) Blue media that is ampicillin-resistant (AmpR gene)

b) Blue media that is not ampicillin-resistant

c) White media that is ampicillin-resistant (AmpR gene)

d) White media that is not ampicillin-resistant


2.18) How is a genomic library screened for an individual gene?

a) With an oligonucleotide probe and hybridization

b) With variable numbers of tandem repeats screening

c) With chromosome walking and northern blotting

d) Via vector-based DNA cloning

e) Through insertional inactivation

2.19) Which of the following allows for creation of cDNA libraries from mRNA but

would not be used for creating a genomic library?

a) DNA ligase

b) DNA polymerase

c) Reverse transcriptase

d) Restriction endonuclease

e) Vector plasmid

2.20) If we have an antibody for a protein within a cDNA library but no knowledge of the

protein sequence, protein expression can be turned on and radioactively labeled through

which technique?

a) Southern blotting

b) Northern blotting

c) Western blotting

d) Hybridization

e) PCR



2.21) If the cDNA sequence of protein at the C-terminus and N-terminus is known, back

translation and oligonucleotide primers can be used in which of the following methods to

create more of the target cDNA?



c) Western blotting

d) Hybridization

e) PCR

2.22) If a gene is expressed within human liver cells, which of the following cells can be

used to create a genomic library?

a) Liver

b) Heart

c) Spleen

d) Bone marrow

e) Any human cell

2.23) If a gene is expressed within human liver cells, which of the following cells can be

used to create a cDNA library?

a) Liver

b) Heart

c) Spleen

d) Bone marrow

e) Any human cell

3.1) Which of the following sequences is most likely to be a restriction enzyme

recognition sequence?

a) 5’ GTCCTG, 3’ CAGGAC

b) 5’ TACGAT, 3’ ATGCTA

c) 5’ CTTAAG, 3’ GAATTC

d) 5’ ATCCTA, 3’ TAGGAT

3.2) A series of patients in a small town visit the hospital complaining of bloody diarrhea,

fatigue, and confusion. Physical exams reveal neurological deficits, and laboratory tests

show anemia, thrombocytopenia, and uremia. Peripheral blood smears show fragmented

RBCs, but subsequent Coombs tests are negative. After careful questioning, the doctors

discover that each patient frequents the same fast-food burger joint. The physicians

identify the causative agent with serological testing and stool cultures appearing metallic

green. Which of the following restriction enzymes is associated with this bacterium?

a) AluI

b) BamHI

c) EcoRI

d) HaeIII

e) NotI

4) Restrictions enzymes that create staggered cuts with a special affinity (if reunited)

leave ____ ends. Linkers may be needed for DNA ligation if cutting results in ____ ends.

a) Blunt; Blunt

b) Blunt; Sticky

c) Sticky; Blunt

d) Sticky; Sticky



3 –Use Of Recombinant DNA Techniques In Medicine

1) Which of the following uses labeled antibodies for specific proteins?



c) Western blotting

d) B and C

e) A, B, and C

2.1) Dideoxynucleotides lack which hydroxyl groups, preventing synthesis of adjacent

nucleotides in a growing DNA chain?

a) 1’ and 2’

b) 2’ and 3’

c) 3’ and 4’

d) 4’ and 5’


2.2) In the dideoxy (Sanger) method of determining the sequence of bases in a DNA

molecule, which of the following is NOT a normal deoxynucleotide that is found in one

of the four test tubes?

a) dATP

b) dTTP

c) dCTP

d) dGTP

e) dUTP

2.3) Given the DNA template 3’ TGCACTAT, 5’ primer 12345678, what positions (5’

numbered) would correspond to the resultant polynucleotide if synthesis is terminated

with the deoxyribonucleoside triphosphate (ddNTP) ddGTP?

a) 1, 6, and 8

b) 3 and 5

c) 2

d) 4 and 7

3) Which of the following is true of DNA cloning and not polymerase chain reaction

(PCR) for amplifying DNA?

a) DNA is heated to create two separate strands and cooled to attach a primer

b) Twenty amplification rounds creates a million-fold increase in DNA

c) Two oligonucleotide primers are complimentary to a sequence

d) DNA is incorporated into a vector

e) Primers, 4 ddNTPs, and heat stable DNA polymerase are used

4) Which of the following uses probes to recognize mutations that do not occur at

restriction enzyme sites, where the DNA is considered mutant if the probe binds?

a) DNA sequencing

b) Restriction fragment length polymorphism (RFLP)

c) Variable number of tandem repeats (VNTR)

d) Allele specific oligonucleotide (ASO)

e) Sanger method

5) VNTRs, also known as minisatellites, can be used in DNA profiling by comparing

restriction fragment patterns. Which of the following would have identical patterns?



a) Brothers

b) Sisters

c) Semi-identical twins

d) Fraternal (dizygotic) twins

e) Monozygotic twins

6) Which of the following, which are all created by recombinant DNA techniques, was

the first successful alternative to previous, possibly infectious, solutions?

a) Hepatitis B vaccine

b) Human insulin

c) Growth hormone

d) Factor VIII

e) Tissue plasminogen activator

f) Hematopoietic growth factor

g) !-interferon

7.1) Which of the following DNA technology applications would affect the patient and

their descendants?

a) Gene therapy

b) Somatic cell therapy

c) Gene replacement therapy

d) Germline therapy

e) Gene blocking therapy

7.2) Gene replacement therapy is best suited for correcting which type of mutations?

a) Loss-of-function

b) Gain-of-function

c) Dominant negative

d) B and C

e) A, B, and C

7.3) Which of the following gene therapy vectors infects dividing cells and thus can

activate tumor formation?

a) Adenoviral vectors

b) Adeno-associated viral vectors

c) Retroviral vectors

d) Lentiviral vectors

7.4) Which of the following genes is expressed in half of all cancers and has been

inserted in lung tumors in an effort to halt tumor progression?

a) Bcl-2

b) Btk

c) Bax

d) Ki-67

e) P53

7.5) Gene blocking therapies are used for which of the following mutations?

a) Loss-of-function

b) Gain-of-function

c) Dominant negative

d) B and C

e) A, B, and C



4 – Introduction To Medical Genetics

1) Which of the following is relevant to genetics?

a) Cancer

b) Diabetes

c) Pediatric disease

d) Heart disease

e) All of the above

Match the type of genetic disorder with the example diseases:

2.1) Chromosome disorder a) Cleft lip, heart disease, diabetes

2.2) Single gene disorder b) Down syndrome, Turner syndrome

2.3) Multifactorial disorder c) Kaerns-Sayre syndrome, Leber neuropathy

2.4) Mitochondrial disorder d) Sickle cell disease, cystic fibrosis

3) Which of the following has contributed the most over the past 50 years to an increase

in the number of genetic disorders treated and the increase in the proportion of deaths

among children in developed countries?

a) Malnutrition

b) Pathogens

c) Poor sanitation

d) Vaccines

e) Improved public health

4.1) Which of the following is NOT a post-translational modification step in the synthesis

of type I collagen?

a) Proline and lysine residues are hydroxylated

b) Polypeptides associate with each other at COOH ends, sulfide bonding

c) Hydroxylysines are glycosylated in the lysosomes

d) Hydrogen bonds form between hydroxyl groups and hydroxyprolines

e) Pro-collagen is cleaved at NH2 and COOH termini to make the mature protein

4.2) In type II osteogenesis imperfecta (“brittle bone disease”), what amino acid gets

substituted, preventing proper folding and thus resulting in poorly formed collagen type I

fibrils?

a) Proline

b) Lysine

c) Alanine

d) Glycine

e) Valine

5.1) Which of the following types of repeated DNA sequences in the human genome is

found near the centromeres of chromosomes?

a) Single copy DNA

b) Dispersed repetitive DNA

c) Satellite repetitive DNA

d) Minisatellite repetitive DNA

e) Microsatellite repetitive DNA

f) D and E

5.2) Which of the following types of repeated DNA sequences vary in length among

individuals and thus are useful in genetic mapping?



a) Single copy DNA





f) D and E

5.3) Which of the following types of repeated DNA sequences is the most important,

includes protein-coding genes, and comprises about 45% of the human genome?

a) Single copy DNA





f) D and E

6.1) During which phase of mitosis, which takes 1-2 hours to complete, are the

chromosomes lined up at the equatorial plate?

a) Prophase

b) Metaphase

c) Anaphase

d) Telophase

e) Cytokinesis

6.2) At the end of mitosis anaphase, how many separate chromatids exist?

a) 1

b) 2

c) 23

d) 46

e) 92

6.3) In which of the following phases of meiosis does the chiasmata form, marking the

attachment between homologous chromosomes where genetic information can be

exchanged (crossing-over)?

a) Prophase I

b) Metaphase I

c) Anaphase I

d) Telophase I

e) Metaphase II

f) Anaphase II

6.4) Which of the following generates genetic diversity?

a) Mitosis

b) Meiosis reduction division

c) Meiosis equational division

d) All of the above


6.5) What is the result of meiosis equational division?

a) 92 chromosomes, 92 chromatids, 2 cells

b) 46 chromosomes, 92 chromatids, 2 cells

c) 46 chromosomes, 46 chromatids, 2 cells



d) 23 chromosomes, 46 chromatids, 4 cells

e) 23 chromosomes, 23 chromatids, 4 cells

6.6) During which phase of meiosis does synapsis occur, in which homologous

chromosomes pair up, side by side, lying together in perfect alignment (in males, the X

and Y chromosomes, being mostly nonhomologous, line up end to end)?

a) Prophase I

b) Metaphase I

c) Anaphase I

d) Telophase I

e) Metaphase II

f) Anaphase II

6.7) In meiosis, what is meant by bivalent homologous chromosomes?

a) One chromosome in the unit

b) Two chromosome in the unit

c) Four chromosome in the unit

d) Two chromatids in the unit

e) Four chromatids in the unit

6.8) In meiosis, what is meant by a tetrad of homologous chromosomes?

a) One chromosome in the unit

b) Two chromosome in the unit

c) Four chromosome in the unit

d) Two chromatids in the unit

e) Four chromatids in the unit

7) At birth, oocytes are suspended in what phase of meiosis?

a) Prophase I

b) Metaphase I

c) Anaphase I

d) Telophase I

e) Metaphase II

f) Anaphase II

5 – Genetic Variation

1.1) Which of the following types of base substitutions results in a stop codon being

produced (UAA, UAG, UGA in mRNA)?

a) Silent

b) Missense

c) Nonsense

1.2) In splice-site mutations, what sequence always defines the 5’ splice site (donor site)?

a) AT

b) CG

c) AG

d) GT

e) TC

1.3) In splice-site mutations, what sequence always defines the 3’ splice site (acceptor

site)?

a) AT



b) CG

c) AG

d) GT

e) TC

1.4) In a promoter mutation (similar to an enhancer mutation), which of the following is

originally altered?

a) Protein production

b) mRNA production

c) RNA polymerase

d) DNA polymerase

e) Promoter site affinity

1.5) Which of the following mutations would cause a frameshift and thus likely be the

most detrimental?

a) Insertion of 1 base pair

b) Deletion of 3 base pairs

c) Insertion of 3 base pairs

d) Deletion of 9 base pairs

e) Insertion of 15 base pairs

1.6) Transposon mutations, also known as mobile elements or “jumping genes”, cause

what type of mutations?

a) Silent

b) Frameshift

c) Nonsense

d) Missense


1.7) Expanded repeat mutations affect tandem repeated DNA sequences near which of

the following locations?

a) Stop codons

b) Start codons

c) Exon/intron splice sites

d) Disease-related genes

e) Palindromic sequences

2.1) Gain-of-function mutations produce dominant disorders, such as in Huntington and

Alzheimer disease. Which of the following is a gain of function disorder that commonly

affects the feet?

a) Charcot-Marie-Tooth disease

b) Cystic fibrosis

c) Hemophilia

d) Cancer

e) Gaucher disease

2.2) Loss-of-function mutations are often seen in ____ diseases where ____ of the protein

product is lost. Hypercholesterolemia is an exception as the loss-of-function mutation

yields abnormal function in heterozygotes (haploinsufficiency).

a) Dominant; 100%

b) Dominant; 50%

c) Recessive; 100%



d) Recessive; 50%

e) Recessive; 0%

3.1) Sickle cell disease, a !-globin missense mutation, causes cells to change shape

during low oxygen tension. In which of the following locations is this most likely to

occur and cause clinical problems?

a) Veins

b) Heart

c) Arteries

d) Spleen

e) Capillaries

3.2) Which of the following types of mutations is most likely associated with "-

thalassemia and not !-thalassemia?

a) Missense

b) Nonsense

c) Deletion

d) Frameshift

e) Silent

3.3) Which of the following results from a simple mutation and has no production of !-

globin (often fatal in first decade if untreated)?

a) Sickle cell disease

b) HbH disease

c) Hydrops fetalis (Hb Barts)

d) B0 thalassemia

e) B+ thalassemia

3.4) Which of the following affects three of the four "-globin chains, leading to anemia

and splenomegaly?


b) HbH disease


d) B0 thalassemia

e) B+ thalassemia

3.5) Which of the following affects all four "-globin chains, leading to congestive heart

failure (CHF) and possibly neonatal death?


b) HbH disease


d) B0 thalassemia

e) B+ thalassemia

4.1) Nonionizing radation, such as UV light, causes covalent bonds to form between

adjacent pyrimidine bases. This would most likely form a dimer of:

a) Thymine and thymine

b) Adenine and guanine

c) Cystosine and guanine

d) Adenine and thymine

e) Guanine and guanine



4.2) Which of the following is least likely to be caused by mutagens from radiation

and/or chemicals?

a) Replication errors

b) Frameshift mutations

c) Base substitutions

d) Base deletions

e) Gain-of-function mutations

5) Which of the following would result in the highest rate of mutation?

a) Small genes, few hot spots, old age

b) Small genes, few hot spots, old age

c) Large genes, few hot spots, old age

d) Large genes, many hot spots, old age

e) Small genes, few hot spots, young age

6) Which type of DNA repair defect is involved in xeroderma pigmentosum (XP),

leading to skin tumors, photosensitivity, cataracts, and neurological abnormalities?

a) Defective repair of UV-induced damage in transcriptionally active DNA

b) Mutations in the reqQ helicase family

c) Nucleotide repair defects including helicase and endonuclease genes

d) Normal gene product involved in halting the cell cycle after damage

e) Mutation in any of the six DNA mismatch-repair genes

7.1) In sickle cell anemia, glutamic acid is replaced with valine in the hemoglobin (Hb)

gene. Electrophoresis can be used to diagnose this disorder by sorting normal Hb (HbA)

from sickle Hb (HbS) in what way?

a) By protein size

b) By protein shape

c) By protein charge

d) By protein age

e) By protein binding

7.2) Which of the following is NOT true about DNA cloning techniques?

a) They are used to create thousands of copies of human DNA

b) They are very quick, often taking under an hour

c) They are usually needed for Southern blotting

d) They are used in genetically engineering insulin

e) Micrograms of DNA are needed for cloning to work

7.3) Which of the following uses differential electrophoretic mobility of test DNA with

different secondary structures (conformations) through a nondenaturing gel?

a) Direct DNA sequencing

b) Single-strand conformational polymorphism (SSCP) analysis

c) Denaturing gradient gel electrophoresis (DGGE) analysis

d) DNA mismatch cleavage

e) Allele-specific oligonucleotide (ASO) hybridization

f) DNA microarray hybridization

g) Protein truncation

7.4) Which of the following uses reverse transcriptase PCR (RF-PCR) containing a T7

promoter and can detect frameshift, splice site, or nonsense mutations?










7.5) Which of the following uses preferential hybridization of a labeled probe to test

DNA with uniquely complementary base composition?








7.6) Which of the following determines the linear order of nucleotides in test DNA by

chemical cleavage, with the use of flourochrome dye?








7.7) Which of the following uses the migration of DNA duplexes through an

electrophoretic gel with increasing amounts of a denaturant (e.g., chemical, temperature)

until DNA strands separate?








7.8) Which of the following tests DNA of known composition by hybridization of test

DNA to arrays of oligonucleotides ordered on silicone chip or glass slide?








7.9) Which of the following uses hybridization of a labeled probe to test DNA, with

separation of the DNA located at the site of base-pairing mismatch?










6 – Autosomal Dominant And Recessive Inheritance

1.1) Which of the following is true regarding Mendel’s principle of segregation?

a) Paired genes are transmitted together and hereditary factors are blended

b) One member of a paired gene is transmitted and hereditary factors are blended

c) Paired genes are transmitted together and hereditary factors are not blended

d) One member of a paired gene is transmitted and hereditary factors are not

blended

1.2) According to Mendel’s principle of independent assortment, which of the following

alleles (pea plant characteristics) would be transmitted together if they were on different

loci? Round peas and tall plant stalks are dominant characteristics.

a) Round and tall

b) Wrinkled and short

c) Round and short

d) Wrinkled and tall

e) None are transmitted together

2.1) Using a Punnet square, what are the genotype probabilities for offspring if the

maternal genotype is homozygous dominant and the paternal genotype is heterozygous?

a) 100% homozygous dominant, 0% heterozygous, 0% homozygous recessive

b) 50% homozygous dominant, 50% heterozygous, 0% homozygous recessive

c) 25% homozygous dominant, 50% heterozygous, 25% homozygous recessive

d) 0% homozygous dominant, 25% heterozygous, 75% homozygous recessive

e) 0% homozygous dominant, 0% heterozygous, 100% homozygous recessive

2.2) What is the ratio for a typical dihybrid cross?

a) 12:2:1:1

b) 9:3:3:1

c) 6:7:2:1

d) 5:6:4:1

e) 4:4:4:4

3.1) Hemophilia is an X-linked recessive disorder. If a father who is unaffected and a

mother who is affected (homozygous recessive) mate, what is the probability that all of

their three children will be affected?

a) 1/2

b) 1/4

c) 1/6

d) 1/8

e) 1/10

3.2) If a mother and father mate, what is the probability that all three of their children will

either be all boys or all girls?

a) 1/2



b) 1/4

c) 1/6

d) 1/8

e) 1/10

4.1) Given that the prevalence (homozygous recessive) of cystic fibrosis is 1 in 2,500,

what is the prevalence of heterozygous carriers of cystic fibrosis?

a) 1 in 250

b) 1 in 125

c) 1 in 50

d) 1 in 25

e) 1 in 5

4.2) Which of the following describes the Hardy-Weinberg equation solved for a single

variable (allele)?

a) p^2 + 2p*(1-p) + (1-p)^2 = 1

b) p^2 + 2p*(1-p) + p^2 = 1

c) p^2 + 2p*(p-1) + (p-1)^2 = 1

d) (1-p) + 2p^2 + (1-p)^2 = 1

e) (p-1) + 2p^2 + (p-1)^2 = 1

5) Genotypes (genetic constitution at a locus) correspond uniquely to phenotypes (actual

physical or clinical observed trait).

a) True

b) False

6.1) A father brings in his child for a routine physical exam. It is found that the child has

postaxial polydactyly, an extra digit next to the fifth digit. The father has the same trait

and with some questioning it seems the trait does not skip generations. Which of the

following inheritance patterns is most likely?

a) X-linked dominant

b) X-linked recessive

c) Autosomal dominant

d) Autosomal recessive

e) Y-linked

6.2) A child is diagnosed with a rare genetic disease. It is found that the child’s parents

are close relatives (consanguinity). Further questioning of the parents reveals that one of

their grandparents had the same disorder. Which of the following inheritance patterns is

most likely?





e) Y-linked

7.1) What is the recurrence risk of an autosomal dominant disorder if one parent has the

disorder?

a) 100%

b) 75%

c) 50%

d) 25%



e) 0%

7.2) What is the recurrent risk of an autosomal recessive disorder if one parent has the

disorder?

a) 100%

b) 75%

c) 50%

d) 25%

e) 0%

8.1) Which of the following is a frequent cause of the appearance of a genetic disease in

an individual with no previous family history of the disorder, and involves 7 of 8 cases of

achondroplasia?

a) Variable expression

b) Delayed age of onset

c) Germline mosaicism

d) New mutations

e) Reduced penetrance

8.2) Which of the following is associated with the lethal perinatal form of osteogenesis

imperfecta and does not affect somatic cells?




d) New mutations


8.3) Which of the following is involved when individuals have a disease-causing

genotype (e.g. retinoblastoma) but do not develop the disease phenotype?




d) New mutations


8.4) Which of the following complicates the interpretation of inheritance patterns in

families with Huntington disease as fathers tend to show affects before mothers?




d) New mutations


8.5) Which of the following can have complete penetrance but a widely varying severity

of disease, such as in neurofibromatosis type 1 (von Recklinghausen disease)?




d) New mutations


8.6) Marfan syndrome is an autosomal dominant disorder that affects the eye, the

skeleton, and the heart. It is thus said to be which of the following?



a) Anticipation

b) Pleiotropy

c) Genomic imprinting

d) Heterogeneity

e) Repeat expansion

8.7) When mutations at different loci in different families cause the same disease

phenotype, it is said to be which of the following?

a) Anticipation

b) Pleiotropy


d) Heterogeneity

e) Repeat expansion

8.8) Differential activation of genes, depending on the parent from which they are

inherited (e.g. Prader-Willi syndrome or Angelman syndrome), is known as which of the

following?

a) Anticipation

b) Pleiotropy


d) Heterogeneity

e) Repeat expansion

8.9) Diseases that show an earlier age of onset and more severe symptoms in the more

recent generations of a pedigree, such as in myotonic dystrophy, are termed which of the

following?

a) Anticipation

b) Pleiotropy


d) Heterogeneity

e) Repeat expansion

8.10) An increase in certain trinucleotide sequences has been linked to disease, such as

fragile X syndrome. This is termed which of the following?

a) Anticipation

b) Pleiotropy


d) Heterogeneity

e) Repeat expansion

9.1) Which of the following is the proportion of a population's chromosomes that have a

specific allele?

a) Gene frequencies

b) Gene flow

c) Natural selection

d) Founder effect

e) Genetic drift

9.2) Which of the following increases the population frequency of favorable mutations,

such as sickle cell anemia in populations with a high incidence of malaria?

a) Gene frequencies

b) Gene flow




d) Founder effect

e) Genetic drift

9.3) Statistically, smaller populations are more likely to see a higher probability of

uncommon diseases. Larger populations tend to normalize to the theoretical incidence of

the disease. Thus, an increase in which of the following would be seen in small

populations?

a) Gene frequencies

b) Gene flow


d) Founder effect

e) Genetic drift

9.4) Several genetic diseases (e.g., torsion dystonia, Tay-Sachs disease, Gaucher disease)

occur with increased frequency in the Ashkenazi Jewish population. This may be the

result of which of the following?

a) Gene frequencies

b) Gene flow


d) Founder effect

e) Genetic drift

9.5) Which of the following occurs when populations exchange migrants who mate with

one another?

a) Gene frequencies

b) Gene flow


d) Founder effect

e) Genetic drift

7 – Pedigree Analysis

1.1) In a pedigree, a non-shaded symbol means that individual is not affected with the

disease in question and also not a carrier.

a) True

b) False

1.2) If it is known that an individual male is a carrier of a genetic disease, which of the

following shapes would be indicated on a pedigree?

a) Fully-shaded square

b) Half-shaded square

c) Non-shaded square

d) Fully-shaded circle

e) Half-shaded circle

f) Non-shaded circle

1.3) A slash through an individual’s pedigree symbol means:

a) They carrier the genetic disease

b) They are affected by the genetic disease

c) They are not affected by the genetic disease

d) They are immune to the genetic disease



e) They are deceased

2.1) Consanguinity is indicated on a pedigree by which of the following?

a) Arrows between related, mating individuals

b) A single line between related, mating individuals

c) A double line between related, mating individuals

d) A slash through each related, mating individual

e) Shading of each related, mating individual

2.2) Which is true of #2 in the pedigree diagram shown?

a) Father

b) Mother

c) First daughter

d) Second born child

e) Third born child

3) The pedigree symbol shown is which of the following?

a) Consanguinity

b) Brothers (not twins)

c) Sisters (not twins)

d) Identical twins

e) Fraternal twins

4) Which of the following is true if a known pedigree has no carriers and has affected

males and females at points across all generations?





e) Y-linked

5) When creating a pedigree from a family history, if the affected and unaffected

individuals are known the carriers of the genetic disease can be determined.

a) True

b) False

6) A deletion in chromosome 15 can lead to two different diseases, depending on if the

deletion occurred on the paternal or maternal side. However, the pedigree for each case is

the same. This is an example of which of the following?

a) Anticipation

b) Pleiotropy


d) Heterogeneity

e) Repeat expansion

7.1) If an individual mates with their cousin’s son (or daughter), what is the coefficient of

relationship?

a) 1/2

b) 1/4

c) 1/8

d) 1/16

e) 1/32

7.2) First cousins share, on average, how many genes?



a) 1/2

b) 1/4

c) 1/8

d) 1/16

e) 1/32

7.3) On a pedigree of two consanguineous individuals, if each ancestor is counted up to

the common ancestor and then back down to the other individual, what is the coefficient

of relationship if there are 2 counted ancestors?

a) (1/2)^(n-2) = 1

b) (1/2)^(n-1) = 1/2

c) (1/2)^(n) = 1/4

d) (1/2)^(n+1) = 1/8

e) (1/2)^(2n) = 1/16

8 – Sex-Linked And Mitochondrial Inheritance

1) Which of the following is NOT true with regard to the Lyon hypothesis?

a) One X chromosome in each cell is randomly inactivated early in the embryonic

development of females

b) Males are typically mosaics for some X-linked traits and females are not

c) Each cell chooses one of the two X chromosomes at random to be inactivated

d) Once an X chromosome is inactivated, it will remain deactivated in all

descendents of that cell

e) There are some regions of the X chromosome that remain active in all copies

(incomplete X-activation)

2.1) What pedigree symbol indicated an X-linked trait carrier?

a) Shaded square

b) Non-shaded square

c) Square with a dot

d) Shaded circle

e) Non-shaded circle

f) Circle with a dot

2.2) If a male with an X-linked trait has two daughters, who each have three sons, how

many of the father’s grandchildren (statistically) should have the X-linked trait?

a) 1

b) 2

c) 3

d) 4

e) 5

f) 6

3.1) Barr bodies are ____ X chromosomes seen in somatic cells of normal ____, and have

transcribed the XIST gene (to ensure long term stability).

a) Activated; Females

b) Activated; Males

c) Inactivated; Females

d) Inactivated; Males



3.2) Agents such as 5-azacytidine, can have what affect on CG dinucleotides in the 5'

regions of genes?

a) Methylates them and reactivates inactive X chromosomes in vitro

b) Methylates them and inactivates X chromosomes in vitro

c) Demethylates them and reactivates inactive X chromosomes in vitro

d) Demethylates them and inactivates X chromosomes in vitro

3.3) Aneuploid females have ____ Barr bodies and a XXX individual would have ____

Barr bodies.

a) 0; 2

b) 0; 1

c) 0; 0

d) 1; 0

e) 2; 0

4) A man with an X-linked disease mates with a female who does not have the disease

and is not a carrier. If they have 4 sons, how many will have the disease?

a) 4

b) 3

c) 2

d) 1

e) 0

5.1) Which of the following is the most common type of inherited X-linked (recessive)

color blindness?

a) Blue and green

b) Red and blue

c) Blue and yellow

d) Red and green

e) All colors (dichromat)

5.2) Hemophilia, a bleeding disorder that can present with bruising and hemarthroses, is

caused by a deficiency or defect in what clotting factor?

a) Factor XII

b) Factor X

c) Factor VIII

d) Factor V

e) Factor II

5.3) Which of the following diseases is associated with the largest known gene in

humans?

a) Sickle Cell Disease

b) Duchene Muscular Dystrophy

c) Huntington Disease

d) Marfan Syndrome

e) Burkitt Lymphoma

6.1) Fragile X syndrome is responsible for 40% of all cases of X-linked mental

retardation. Which of the following is NOT a symptom of fragile X syndrome?

a) Increased testicular volume

b) Hypermobile joints

c) Long face



d) Large ears

e) Protruding eyes

6.2) Fragile X syndrome shows an affected X chromosome when cultured in media

deficient in which of the following?

a) Thiamin

b) Riboflavin

c) Niacin

d) Folic acid

e) Ascorbic acid

6.3) Which of the following best describes the transmission of fragile X syndrome

(Sherman paradox)?



c) X-linked dominant with reduced penetrance

d) X-linked recessive with reduced penetrance

e) Y-linked

7.1) Which of the following is true about transmission of disease caused by mitochondrial

DNA (mtDNA)?

a) Only females can transmit the disease

b) Only males can transmit the disease

c) Both females and males can transmit the disease

d) Only females can get the disease

e) Only males can get the disease

7.2) Which of the following is NOT true about mtDNA?

a) It contains no introns

b) The rate of mutation is 10 times higher than that of nuclear DNA

c) It contains 2 rRNAs and 22 tRNAs

d) Variable expression in mitochondrial diseases is due to mtDNA heteroplamsy

e) It has many DNA repair mechanisms

8) The larger the proportion of heteroplasmic mutant mtDNA molecules, the more severe

the expression of the disease.

a) True

b) False

9.1) Which of the following is heteroplasmic and has single-base mutations in a tRNA

gene?

a) Leber hereditary optic neuropathy (LHON)

b) Myoclonic epilepsy with ragged-red fiber syndrome (MERRF)

c) Mitochondrial encephalomyopathy and stroke-like episodes (MELAS)

d) Chronic progressive external ophthalmoplegia (CPEO)

e) B and C

9.2) Which of the following is rarely heteroplasmic, has missense mutations in protein-

coding mtDNA genes, and has symptoms beginning in the third decade of life?

a) Leber hereditary optic neuropathy (LHON)

b) Myoclonic epilepsy with ragged-red fiber syndrome (MERRF)

c) Mitochondrial encephalomyopathy and stroke-like episodes (MELAS)

d) Chronic progressive external ophthalmoplegia (CPEO)



e) B and C

9 – Clinical Cytogenetics

1.1) Stalks and satellites are seen on what type of chromosomes?

a) Metacentric

b) Submetacentric

c) Acrocentric

d) Telomeric

1.2) Which of the following involves staining chromosomes during prophase or early

metaphase, before they have reached maximal condensation in metaphase?

a) G-banding (Giemsa)

b) R-banding (Reverse)

c) Q-banding (Quinacrine)

d) C-banding(Constructive heterochromatin)

e) High resolution banding

1.3) Which type of banding involves chromosomes partially digested by trypsin and gives

results similar to the karyotype shown?






1.4) Which type of banding stains near the centromere?






1.5) Which type of banding requires heat treatment and is useful in staining the distal

ends (telomere area) of the chromosome?






1.6) Which type of banding requires a fluorescence microscope and was the first method

developed to produce specific banding patterns?






2.1) Which of the following is used to detect losses or duplication of specific

chromosome regions?

a) Fluorescence in situ hybridization (FISH)

b) Spectral karyotyping



c) Comparative genomic hybridization (CGH)

2.2) Which of the following uses varying combinations of different fluorescent probes in

conjunction with special cameras and image processing software to identify

chromosomes, and is useful in identifying chromosome rearrangements?




2.3) Which of the following uses probes and complimentary base pairing to visualize a

chromosome, is useful for detecting excess chromosome material, and can detect very

small deletions?




3.1) Which of the following is NOT true of polyploidy?

a) It can be caused by fusion of an ovum and a polar body

b) It can be cause by dual sperm fertilization (dispermy)

c) It can be caused by meiotic failure (nondisjunction)

d) It usually ends in abortion or a short life for the affected

e) It is less common in plants than in humans

3.2) How many chromosomes are there in triploidy?

a) 3

b) 24

c) 47

d) 69

e) 92

4.1) Which of the following has the longest expected survival time?

a) Trisomy 13 (Patau syndrome)

b) Trisomy 18 (Edward syndrome)

c) Trisomy 21 (Down syndrome)

Match the common abnormalities with the Autosomal trisomy:

4.2) Prenatal growth deficiency, omphalocele, hand abnormalities a) Trisomy 13

4.3) Low nasal root, decreased muscle tone, duodenal obstruction b) Trisomy 18

4.4) Oral-facial clefts, postaxial polydactyly, microphthalmia c) Trisomy 21

5.1) Which of the following results in taller than average males, a slight reduction in IQ,

possible aggressive behavior, and few physical problems?

a) 45,X (Turner syndrome)

b) XXY (Klinefelter syndrome)

c) XXX (Trisomy X)

d) 47,XYY syndrome

5.2) Which of the following has a characteristically broad “webbed neck”, reduced

stature, and ankle/wrist swelling?



c) XXX (Trisomy X)

d) 47,XYY syndrome



5.3) Which of the following has very few consequences but sometimes sterility,

menstrual irregularity, or mild mental retardation?



c) XXX (Trisomy X)

d) 47,XYY syndrome

5.4) Which of the following results in taller than average males, a slight reduction in IQ,

sterility, and can involves treatment of gynecomastia with mastectomy and testosterone?



c) XXX (Trisomy X)

d) 47,XYY syndrome

6.1) Which of the following is true of unbalanced chromosomal abnormalities

(unbalanced rearrangement)?

a) Chromosomal material is gained

b) Chromosomal material is lost

c) Chromosomal material is either lost or gained

d) Chromosomal material is neither lost nor gained

6.2) Translocation is the exchange of genetic material between:

a) Opposite ends of a chromosome

b) Homologous chromosomes

c) Non-homologous chromosomes

d) Parents

e) Offspring

6.3) Microscopically observable chromosome deletions, which may be either terminal or

interstitial, usually affect a fairly large number of genes and produce recognizable

syndromes.

a) True

b) False

6.4) Uniparental disomy is the cause of about 30% of Prader-Willi cases. This could

occur if the mother contributed ____ copies of the chromosome and the father contributes

____ copies.

a) 2; 2

b) 1; 1

c) 0; 0

d) 0; 2

e) 2; 0

6.5) Which of the following can arise from unequal crossover, or can occur among the

offspring of reciprocal translocation carriers?

a) Isochromosome

b) Uniparental disomy

c) Inversion

d) Duplication

e) Deletion

6.6) Ring chromosomes can form from deletion of what part(s) of the chromosome?

a) One terminal and one interstitial part



b) Two terminal and one interstitial part

c) One terminal and two interstitial parts

d) Two terminal parts

e) Two interstitial parts

6.7) An inversion including the centromere is called pericentric and one not involving the

centromere is called paracentric. If a chromosome is symbolized as ABCDEFG, which of

the following would be considered an inversion?

a) FEFCDAB

b) ABEDCFG

c) ABCEFGD

d) FGCBADE

e) CBAGFED

6.8) Isochromosome Xp, a chromosome division along the axis perpendicular to its usual

axis of division, usually results in features similar to which of the following?



c) XXX (Trisomy X)

d) 47,XYY syndrome

7.1) Imprinting is important in deletions in which of the following chromosomes, leading

to Prader-Willi syndrome if the father has the deletion or Angelman syndrome if the

mother has the deletion?

a) 1p36

b) 7q1

c) 8q24

d) 15q11-13

e) 17p13.3

7.2) Which of the following microdeletion syndromes can be produced by the deletion of

only a very small telomeric segment of 4p and gives wide-spaced eyes and a cleft lip?

a) Wolf-Hirschhorn syndrome

b) Langer-Giedion syndrome

c) Miller-Dieker syndrome

d) Smith-Magenis syndrome

e) Williams syndrome

f) Rubinstein-Taybi syndrome

g) Alagille syndrome

8.1) Chronic myelogenous leukemia (CML) involves translocation of a proto-oncogene

abl from chromosome ____ to ____ (Philadelphia chromosome). The product increases

tyrosine kinase activity, leading to malignancy.

a) 8; 14

b) 9; 14

c) 8; 22

d) 9; 22

e) 14; 22

8.2) Burkitt lymphoma is a childhood jaw tumor involving reciprocal translocation of the

myc proto-oncogene from ____ to ____ and involves regulation near immunoglobulin.

a) 8; 14



b) 9; 14

c) 8; 22

d) 9; 22

e) 14; 22

10 – Inborn Errors Of Metabolism

1) Phenylketonuria falls under which of the following classes of inherited metabolic

disorders?

a) Carbohydrate disorders

b) Amino acid disorders

c) Lipid disorders

d) Organic acid disorders

e) Urea cycle defects

f) Energy production defects

g) Heavy metal transport defects

2.1) Which of the following is a glycogen storage disorder affecting glucose-6-

phosphate?

a) Classical galactosemia

b) Von Gierke disease

c) Phenylketonuria (PKU)

d) Cystinuria disease

e) Medium-chain acyl-coenzyme A dehydrogenase (MCAD) disorder

2.2) Which of the following disorders would present with vomiting and lethargy with an

accumulation of fatty acid intermediates during fasting?






2.3) Which of the following presents with retardation and requires limiting intake of a

particular amino acid?






2.4) Which of the following results from a missense mutation of exon 6 and requires

elimination of a particular dietary carbohydrate?






2.5) Which of the following is an autosomal recessive disorder and requires

administration of large amounts of water (4-6 L per day) as a treatment option?








2.6) Which of the following requires treatment to reduce the load of accumulated copper?

a) Ornithine transcarbamylase (OTC) disorder

b) Mucopolysaccharidoses (MPS)

c) Sphingolipidoses (I-cell)

d) Wilson disease (WND)

e) Hemochromatosis

2.7) Which of the following is an X-linked recessive urea cycle disorder with treatment

aimed at reducing the amount of ammonia compounds in the blood?





e) Hemochromatosis

2.8) Which of the following is a lysosomal storage disorder presenting with enlarged

organs, multiorgan failure, and debilitating skeletal disease?





e) Hemochromatosis

2.9) Which of the following is an autosomal recessive disorder of iron metabolism?





e) Hemochromatosis

2.10) Which of the following is a lysosomal storage disorder presenting with multisystem

deterioration causing hearing, vision, joint, and cardiovascular dysfunction?





e) Hemochromatosis

3) Which of the following is NOT true regarding dietary management of inborn errors of

metabolism?

a) Financial affects should be considered

b) Lifestyle affects should be considered

c) Emotional affects should be considered

d) Diets must have adequate calories and nutrients for normal growth

e) Modifications can be reduced and eliminated into puberty



4) Hemochromatosis is more common in northern Europeans than in Asians and

Africans. It is thought that the gene for this disorder gave a selective advantage during

deficiencies in which of the following?

a) Folic acid

b) Oxygen

c) Iron

d) Sodium

e) Potassium

5) Which of the following are used to create complex genetic profiles that are predictive

of drug response (pharmacogenomics); particularly when the exact DNA sequence

causing a varied drug response has not been identified.

a) Single nucleotide polymorphisms (SNPs)

b) Dinucleotide polymorphisms (DPs)

c) Trinucleotide polymorphisms (TPs)

d) Monoclonal antibodies

e) Thiopurine methyl transferases (TPMTs)

11 – Gene Mapping And Cloning

1.1) Which of the following is true of genetic mapping and not physical mapping?

a) Cytogenic techniques are used to find loci distances

b) Molecular techniques are used to find loci distances

c) Frequency of meiotic crossovers are used to find loci distances

d) Specific locations to markers are not assigned

e) Specific locations of disease genes are not assigned

1.2) Which of the following is an anatomic relationship (not segregational) between two

genetic loci represented on the same chromosomal pair?

a) Haplotype

b) Syntenic

c) Marker

d) Linking

e) Contig map

1.3) Which of the following uses a linked marker and then canvases the region around the

marker to locate and clone the disease gene?

a) Recombination hot spots

b) Positional cloning

c) Sequence tagged sites (STSs)

d) Artificial chromosomes

e) Syntenic

1.4) Five centiMorgans (cM) represents a recombination frequency of about:

a) 0.5%

b) 1%

c) 5%

d) 50%

e) 100%

1.5) Alleles on the same chromosome that are usually inherited together are said to be:

a) Associated



b) Functional

c) Syntenic

d) Recombinant

e) Linked

1.6) Nearly the entire human DNA library has been cloned into which of the following,

which can accommodate large DNA inserts?

a) Sequence tagged sites (STSs)

b) Yeast artificial chromosomes (YACs)

c) Bacterial artificial chromosomes (BACs)

d) Bacteriophage artificial chromosomes (BACs)

e) P1 artificial chromosomes (PACs)

1.7) About 60% of human genes, including nearly all housekeeping genes and most of the

widely expressed genes, are which of the following?

a) Methylated AT islands

b) Methylated CG islands

c) Unmethylated AT islands

d) Unmethylated CG islands

1.8) Which of the following describes linkage phase?

a) The arrangement of alleles on each chromosome

b) When crossing over takes place

c) When rearrangement takes place

d) When mutation takes place

e) Meiosis metaphase

1.9) On a pedigree, assuming multiple offspring in each generation, which generation is

uninformative mating as linkage phase cannot be determined?

a) I

b) II

c) III

d) IV

e) V

1.10) Which of the following involves a series of DNA fragments that overlap partially?

a) Exon trapping

b) Contig map

c) Expressed sequence tags (ESTs)

1.11) Which of the following is used to determine which alterations in DNA are disease

causing genes?

a) Exon trapping

b) Contig map


1.12) Which of the following uses cDNA libraries flanked by PCR primers?

a) Exon trapping

b) Contig map


2) The closer genes are to each other, the ____ they are to undergo recombination and the

____ they are to be linked.

a) Less likely; Less likely



b) Less likely; More likely

c) More likely; More likely

d) More likely; Less likely

3.1) What recombination frequency is used for loci that are not linked?

a) " = 0

b) " = 0.1

c) " = 0.5

d) " = 0.9

e) " = 1

3.2) What is the likelihood ratio equation for testing the hypothesis that two loci are

linked with recombination frequency of " = 0.1?

a) (Likelihood of observing pedigree data if " = 0.1) /

(Likelihood of observing pedigree data if " = 0.5)

b) (Likelihood of observing pedigree data if " = 0.5) /


c) (Likelihood of observing pedigree data if " = 0.1) /

(Likelihood of observing pedigree data if " = 1)

d) (Likelihood of observing pedigree data if " = 1) /


e) (Likelihood of observing pedigree data if " = 0.1) /


3.3) What logarithm of odds (LOD) score is conventionally accepted as evidence of

linkage?

a) -3.0

b) -2.0

c) -1.0

d) 0

e) 1.0

f) 2.0

g) 3.0

3.4) What LOD score is accepted as evidence of no linkage?

a) -3.0

b) -2.0

c) -1.0

d) 0

e) 1.0

f) 2.0

g) 3.0

4) With efficient genotyping techniques and large numbers of markers (developed over

the past two decades), it is now commonplace to map a disease gene with only a few

weeks or months of laboratory and statistical analysis.

a) True

b) False

5.1) A study showed that 78% of patients with hemochromatosis had the A3 allele of the

human leukocyte antigen (HLA) A locus, whereas only 27% of unaffected subjects

(controls) had this allele. This is an example of:



a) Association

b) Functionality

c) Syntenicity

d) Recombination

e) Linking

5.2) If a large collection of families are studied and it is found that there is no preferential

association between the disease gene and a specific allele at a linked marker locus, the

two loci are said to be in:

a) Linkage equilibrium

b) Linkage disequlilibrium

5.3) Linkage refers to a statistical relationship between two traits in the general

population. The two traits occur together in the same individual more often than would be

expected by chance alone.

a) True

b) False

6.1) If four chromosomes synapse into a cross-shaped configuration during meiotic

prophase, the organism is heterozygous for a:

a) Pericentric inversion

b) Deletion

c) Translocation

d) Paracentric inversion


6.2) Deletions and translocations (e.g. Xp21 gene and DMD) can interrupts the target

gene, leading to disease and providing a means of mapping the disease.

a) True

b) False

7) Which of the following techniques begins with a somatic cell that contains a single

human chromosomes?

a) In situ hybridization

b) Somatic cell hybridization

c) Radiation hybrid mapping

8) Which of the following is contained in the genomic library as well as the cDNA

library?

a) Non-coding DNA

b) Promoters

c) Enhancers

d) Introns

e) Exons

9) A patient presents with an inherited clotting disorder. Which of the following would be

the most plausible candidate gene (positional candidate) for further analysis?

a) Collagen gene

b) Fibrillin gene

c) Elastin gene

d) Platelet gene

e) Hemoglobin gene



12 – Developmental Genetics

1.1) Which of the following, like Xenopus laevis (frog), has a transparent embryo and is

easy to maintain in large populations?

a) Papio hamadryas (baboon)

b) Mus musculus (mouse)

c) Danio rerio (zebrafish)

d) Drosophila melanogaster (fruit fly)

e) Caenorhabditis elegans (roundworm)

1.2) The fate of every cell is known in which of the following?

a) Papio hamadryas (baboon)

b) Mus musculus (mouse)

c) Danio rerio (zebrafish)

d) Drosophila melanogaster (fruit fly)

e) Caenorhabditis elegans (roundworm)

2.1) Mutations to which of the following paracrine signal molecules leads to autosomal

dominant disorders such as achondroplasia, hypochondroplasia, and thanatophoric

dysplasia?

a) Fibroblast growth factor (FGF)

b) Sonic hedgehog (Shh)

c) Wingless (Wnt)

d) Transforming growth factor ! (TGF-!)

2.2) Mutation of the DNA transcription factor Sox 10 leads to what syndrome?

a) Turner syndrome

b) Hirschsprung disease

c) Treacher Collins syndrome

d) Pierre Robin sequence

e) Pfeiffer syndrome

2.3) A mutation in the LAMC2 gene that encodes a subunit of laminin (in extracellular

matrix, ECM) would lead to which of the following?

a) Excessive bruising

b) Marfan syndrome

c) Skin tearing

d) Blister formation

e) Inability to sweat

3) Mutations in which of the following can produce pleiotropic effects (more than one

genetic effect) due to multiple targets being affected?

a) Paracrine signal molecules

b) DNA transcription factors

c) Extracellular matrix proteins

Match the ECM protein mutation with the associated development disorder:

4.1) Marfan syndrome a) Collagen

4.2) Osteogenesis imperfecta b) Fibrillin

4.3) Junctional epidermolysis bullosa (JEB) c) Elastin

4.4) Supravalvular aortic stenosis d) Laminin

Match the gene mutation with the associated phenotypic expression:

5.1) FGF a) Hirschsprung disease (hypomobility of the bowel)



5.2) SOX10 b) Holt-Oram syndrome (anterior/posterior upper limb defects)

5.3) ZIC3 c) Holoprosencephaly (sloping forehead, single nostril, palpebral fissures)

5.4) SHH d) Situs inversus (left/right organ rearrangement)

5.5) TBX5 e) Craniosynostosis (premature fusion of the cranial sutures)

6) Maintenance of the apical ectodermal ridge (AER) is dependent on a signal from a

posterior portion of the limb bud known as the zone of polarizing activity (ZPA). Which

of the following is the molecule associated with the ZPA?

a) FGF 2, paracrine molecule

b) FGF 4, paracrine molecule

c) FGF 8, paracrine molecule

d) SHH, transcription factor

7) Altering or disrupting a particular mouse gene so that it is not expressed is termed a

knockout model. Which of the following describes a human transgenic model for mice?

a) An immune-deficient mouse with a human immune system

b) A mouse with a human genome

c) A human with a mouse genome

d) A mouse with a human gene inserted into somatic cells

e) A mouse with a human gene inserted into embryonic stem cells

8) Which of the following is true regarding the temporal and spatial colinearity of 5’

HOX (homeobox) genes compared with 3’ HOX genes?

a) 3’ HOX genes are expressed before and anterior to 5’ HOX genes

b) 3’ HOX genes are expressed before and posterior to 5’ HOX genes

c) 5’ HOX genes are expressed before and anterior to 3’ HOX genes

d) 5’ HOX genes are expressed before and posterior to 3’ HOX genes

9.1) Which of the following would be considered homeobox paralogs?

a) HOXa13 and HOXa14

b) HOXa13 and HOXb14

c) HOXa13 and HOXb13

9.2) During axial development, if antenna become legs, which of the following occurred:

a) Paralog swapping

b) Homeodomain stability

c) Spatial colinearity

d) Temporal colinearity

e) Homeotic transformation

10) Insulin promoter factor 1 (IPF1) is necessary for maturation and differentiation of

pancreatic precursor cells. Which of the following cell types does IPF1 stimulate?

a) # (alpha)

b) ! (beta)

c) $ (gamma)

d) All of the above


13 – Cancer Genetics

1.1) Which of the following has a two-hit model where the first mutation is inherited?

a) Tumor suppressor genes

b) Oncogenes



c) DNA repair genes

1.2) Which of the following were first identified through the study of retroviruses and are

activated by a gain-of-function mutation?


b) Oncogenes

c) DNA repair genes

1.3) Defects in which of the following can lead to genomic instability and includes the

disease xeroderma pigmentosum?


b) Oncogenes

c) DNA repair genes

Match the description with the associated cancer gene:

2.1) Major contributor of inherited breast cancer, incorrect DNA repair a) APC

2.2) On short arm of chromosome 5, 85% of all colon cancers b) p53

2.3) Chromosome 17, downregulates RAS c) BRCA1

2.4) Mutations are found in more than half of all human cancers d) NF1

3) In the Knudsen model of carcinogenesis, an individual would need either ____

retinoblastoma gene mutation to be inherited and ____ to be an unspecified event, or

would need ____ to be an unspecified event for cancer to occur.

a) 1; 1; 1

b) 1; 1; 2

c) 1; 2; 1

d) 2; 1; 2

e) 2; 2; 2

4.1) Gain-of-function mutations are seen in the ____ gene in 50% of colon cancers,

which increases signal transduction and thus cell proliferation.

a) APC, chromosome 5q

b) KRAS, chromosome 12q

c) SMAD4, chromosome 18q

d) TP53, chromosome 17p

4.2) Loss-of-function mutations are seen in the ____ gene in 50% of colon cancers, which

normally prevents tumors from growing.

a) APC, chromosome 5q

b) KRAS, chromosome 12q

c) SMAD4, chromosome 18q

d) TP53, chromosome 17p

5) Telomerase is a reverse transcriptase that ____ the telomeric segments after cell

division. ____ of this enzyme if found in 85-90% of tumor cells.

a) Removes; Activation

b) Removes; Deactivation

c) Replaces; Activation

d) Replaces; Deactivation

6) In gene mapping, loss of heterozygosity (LOH) for a locus is a signpost for what?

a) Tumor gene near the deleted locus

b) Tumor gene near the inserted locus

c) Tumor suppressor gene near the deleted locus



d) Tumor suppressor gene near the inserted locus

7) Which of the following is true of mutations that increase cancer susceptibility?

a) Dominant inheritance pattern, dominant in cellular function

b) Dominant inheritance pattern, recessive in cellular function

c) Recessive inheritance pattern, dominant in cellular function

d) Recessive inheritance pattern, recessive in cellular function

Match the syndrome or tumor associated with mutation in the gene:

8.1) Breast cancer, interacts with DNA repair protein complex a) RB1

8.2) Male breast cancer, interacts with DNA repair protein b) APC

8.3) Familial melanoma c) BRCA2

8.4) Down-regulates RAS protein d) NF1

8.5) Li-Fraumeni syndrome e) MLH1, MSH2

8.6) Interacts with !-catenin in Wnt signaling pathway f) CDKN2A (p15)

8.7) Retinoblastoma; osteosarcoma g) TP53

8.8) DNA repair mismatch, HNPCC disease h) BRCA1

8.9) A patient presents with noninherited papillary thyroid carcinoma after spending time

near Chernobyl, Ukraine. Which of the following somatic gene alterations is the most

likely?

a) APC

b) NF1

c) RET

d) TP53

e) BRCA1

9) Which of the following in tumor DNA indicates that the normal tumor suppressor gene

as well as the polymorphic markers surrounding it have been lost leaving only the

abnormal copy of the tumor suppressor gene?

a) Chromosome integrity

b) Genomic instability

c) Loss of heterozygosity

d) Recombination

e) Linkage

10.1) 80-90% of TP53 mutations are of what type?

a) Missense

b) Nonsense

c) Silent

d) Reciprocal

e) Deletion

10.2) The TP53 gene encodes a transcription factor that can induce either cell cycle arrest

or apoptosis in response to damaged DNA.

a) True

b) False

14 – Multifactorial Inheritance

1.1) If pyloric stenosis occurs in 1/200 males and 1/1000 females, which of the following

is true?

a) Males have a lower threshold of liability and a lower proband



b) Males have a lower threshold of liability and a higher proband

c) Females have a lower threshold of liability and a lower proband

d) Females have a lower threshold of liability and higher proband

1.2) Which of the following is true of multifactorial traits?

a) Men tend to have higher quantitative values

b) Women tend to have higher quantitative values

c) Populations distribute heavier to the low quantitative values

d) Populations distribute heavier to the high quantitative values

e) Populations distribute Gaussian (normal)

1.3) Which of the following is true of a concordant trait between twins?

a) It is more common for the male to have the trait

b) It is more common for the female to have the trait

c) It is more common for the older twin to have the trait

d) It is more common for the younger twin to have the trait

e) Both share the trait

1.4) Heritability is a measure of the proportion of population variation in a disease that

can be attributed to genes. Which of the following estimates heritability given that cMZ

is the concordance rate of monozygotic twins and cDZ is the concordance rate of

dizygotic twins?

a) h = cMZ - cDZ

b) h = cMZ + cDZ

c) h = 2 * (cMZ – cDZ)

d) h = 2 * (cMZ + cDZ)

e) h = cMZ * cDZ

2) Which of the following is NOT true of the criteria for recurrence risk which indicate

that a trait shows multifactorial inheritance?

a) The recurrent risk is higher if more than one family member is affected

b) If the expression of the disease in the proband is more severe, the recurrence

risk is higher

c) The recurrence risk is higher if the proband is of the less commonly affected

sex

d) The recurrence risk for the disease usually increases more rapidly in remotely

related individuals

e) If the prevalence of the disease in a population is “f”, the risk for offspring and

sibling probands is approximately the square root of “f”

3.1) What is the expected correlation coefficient, which measures the degree of

homogeneity of a trait, for dizygotic twins?

a) -1.0

b) -0.5

c) 0

d) 0.5

e) 1.0

3.2) What type of study would allow for comparison of similar genetic traits with

different environmental factors?

a) Monozygotic twin studies

b) Dizygotic twin, same father studies



c) Dizygotic twin, different father studies

d) Monozygotic adoption studies

e) Siblings (non-twins)

4.1) If an individual has breast cancer and is considered a phenocopy, which of the

following is true?

a) They will have a BRCA1 mutation

b) They will have a BRCA2 mutation

c) They will have either a BRCA1 or a BRCA2 mutation

d) They will have both a BRCA1 and a BRCA2 mutation

e) They will have neither a BRCA1 nor a BRCA2 mutation

4.2) During a genomic scan, if a sufficiently ____ LOD score is obtained with a

polymorphism, it is assumed that the region around this polymorphism ____ contain(s) a

qualitative trait (QTL).

a) Small; May

b) Small; Never

c) Large; May

d) Large; Never

4.3) Which of the following gives evidence that a marker is linked to a susceptibility

locus for siblings in the affected sib-pair method?

a) 0% marker polymorphism

b) Less than 50% marker polymorphism

c) 50% marker polymorphism

d) More than 50% marker polymorphism

e) 100% marker polymorphism

5) Each LDL receptor gene class of mutations reduces the number of effective LDL

receptors and results in decreased LDL uptake and hence elevated levels of circulating

cholesterol. A class I mutation would lead to an individual with what percentage of

normal LDL receptors?

a) 0%, very high blood cholesterol

b) 25%, quadruple blood cholesterol

c) 50%, double blood cholesterol

d) 75%, increased blood cholesterol

e) 100%, normal blood cholesterol

6.1) Which of the following protein (gene) mutations leads to coronary heart disease via

increased LDL levels, similar to the LDLR gene in familial hypercholesterolemia (FH)?

a) SGCB

b) TNNT2

c) LQT1

d) HERG

e) APOB

6.2) Mutations to the leptin hormone gene lead to what disorder?

a) Coronary heart disease

b) Hypertension

c) Obesity

d) Diabetes mellitus

e) Long QT syndrome



6.3) Type ____ diabetes is HLA-associated and most cases of autosomal ____ mature

onset diabetes of young (MODY) are caused by mutations in any of the six specific

genes.

a) I; Dominant

b) I; Recessive

c) II; Dominant

d) II; Recessive

15 – Osteopathic Considerations In The Study Of Molecular Biology And Genetics

1) Genes dictate the formation of specific proteins. Explain how the principle that

structure and function are inter-related applies to protein synthesis.

2) Describe the role of genetics in the creation of integrated and coordinated body

structures and functions.

3) Explain how the osteopathic tenet that structure and function are interrelated applies to

cancer.

James Lamberg



AnswerKey

Genetics #1

1) B

2) B

3) E

4) E

5) D

6) B

7) B

8) C

9) B

10) C

11) B

12) A

13) C

14) D

15) C

Genetics #2

1.1) C

1.2) E

2.1) A

2.2) C

2.3) C

2.4) D

2.5) C

2.6) D

2.7) E

2.8) C

2.9) A

2.10) B

2.11) B

2.12) E

2.13) E

2.14) D

2.15) C

2.16) D

2.17) C

2.18) A

2.19) C

2.20) C

2.21) E

2.22) E

2.23) A

3.1) C

3.2) C

4) C

Genetics #3

1) C

2.1) B

2.2) E

2.3) B

3) D

4) D

5) E

6) A

7.1) D

7.2) A

7.3) C

7.4) E

7.5) D

Genetics #4

1) E

2.1) B

2.2) D

2.3) A

2.4) C

3) E

4.1) C

4.2) D

5.1) C

5.2) F

5.3) A

6.1) B

6.2) E

6.3) A

6.4) B

6.5) E

6.6) A

6.7) B

6.8) E

7) A

Genetics #5

1.1) C

1.2) D

1.3) C

1.4) E

1.5) A

1.6) B

1.7) D

2.1) A

2.2) D

3.1) E

3.2) C

3.3) D

3.4) B

3.5) C

4.1) A

4.2) E

5) D

6) C

7.1) C

7.2) B

7.3) B

7.4) G

7.5) E

7.6) A

7.7) C

7.8) F

7.9) D

Genetics #6

1.1) B

1.2) E

2.1) B

2.2) B

3.1) D

3.2) B

4.1) D

4.2) A

5) B

6.1) C

6.2) D

7.1) C

7.2) D

8.1) D

8.2) C

8.3) E

8.4) B

8.5) A

8.6) B

8.7) D

8.8) C

8.9) A

8.10) E

9.1) A

9.2) C

9.3) E

9.4) D

9.5) B

Genetics #7

1.1) B

1.2) B

1.3) E

2.1) C

2.2) D

3) D

4) C

5) B

6) C

7.1) D

7.2) C

7.3) B

Genetics #8

1) B

2.1) F

2.2) C

3.1) C

3.2) C

3.3) A

4) E

5.1) D

5.2) C

5.3) B

6.1) E

6.2) D

6.3) C

7.1) A

7.2) E

8) A

9.1) E

9.2) A

Genetics #9

1.1) C

1.2) E

1.3) A

1.4) D

1.5) B



1.6) C

2.1) C

2.2) B

2.3) A

3.1) E

3.2) D

4.1) C

4.2) B

4.3) C

4.4) A

5.1) D

5.2) A

5.3) C

5.4) B

6.1) C

6.2) C

6.3) A

6.4) E

6.5) D

6.6) D

6.7) B

6.8) A

7.1) D

7.2) A

8.1) D

8.2) A

Genetics #10

1) B

2.1) B

2.2) E

2.3) C

2.4) A

2.5) D

2.6) D

2.7) A

2.8) C

2.9) E

2.10) B

3) E

4) C

5) A

Genetics #11

1.1) C

1.2) B

1.3) B

1.4) C

1.5) E

1.6) B

1.7) D

1.8) A

1.9) A

1.10) B

1.11) A

1.12) C

2) B

3.1) C

3.2) A

3.3) G

3.4) B

4) A

5.1) A

5.2) A

5.3) B

6.1) C

6.2) A

7) C

8) E

9) D

Genetics #12

1.1) C

1.2) E

2.1) A

2.2) B

2.3) D

3) B

4.1) B

4.2) A

4.3) D

4.4) C

5.1) E

5.2) A

5.3) D

5.4) C

5.5) B

6) D

7) E

8) A

9.1) C

9.2) E

10) B

Genetics #13

1.1) A

1.2) B

1.3) C

2.1) C

2.2) A

2.3) D

2.4) B

3) B

4.1) B

4.2) D

5) C

6) C

7) B

8.1) H

8.2) C

8.3) F

8.4) D

8.5) G

8.6) B

8.7) A

8.8) E

8.9) C

9) C

10.1) A

10.2) A

Genetics #14

1.1) A

1.2) E

1.3) E

1.4) C

2) D

3.1) D

3.2) D

4.1) E

4.2) C

4.3) D

5) C

6.1) E

6.2) C

6.3) A

Quiz Medical Genetics

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