Genetics - 2005
1. Which of the following would be the percentage of women with a recessive disease
attached to the X, when the amount of defected alleles in the population is 1%?
a. 0.01%.
b. 0.1%.
c. 10%.
d. 20%.
e. 50%.
2. In a certain population, the percentage of homozygotes in allele A is 28%. The
percentage of homozygotes in allele B is 8%. Which of the following is likely if A and B
are both of the same gene?
a. There is a selective preference for homozygosity in allele A.
b. There is a selective preference for homozygosity in allele B.
c. There is a selective preference for heterozygosity.
d. There is insufficient data to determine.
3. The diagram below shows a couple who
have had a baby that has a rare recessive
disease, whose gene sits on chromosome
11. The gene itself is unknown, but a
polymorphic marker attached to it is known,
and has been genetically mapped. The
family would like to know if the next baby
will be sick. They have been told it will not,
and in reality it did come out sick. Which of
the following has gone wrong?
a. A mistake in the test caused the
identification of GATA(16) instead of
GATA(18) in the fetus.
b. The nurse who did the test switched the DNA of the fetus with that of another.
c. The gene is not on chromosome 11.
d. During the mother’s meiosis there was a recombination between the polymorphic
marker and the gene carrying the disease.
4. Which of the following is true in relation to insufficiency mutations in the genes?
a. An insufficiency of 5 bases will always cause a change in the open reading frame.
b. An insufficiency of 5 bases will not always cause a change in the open reading
frame.
c. An insufficiency of 9 bases will never cause a change in the open reading frame.
d. An insufficiency of 9 bases will always cause a change in the open reading frame.
5. Which of the following is STS?
a. Polymorphic marker.
b. A unique site in the genome.
c. A repeating sequence in the genome.
d. A regulatory gene (does not code protein).
6. Which of the following is proteomics?
a. A research which deals in matching medicine with patients based on their
genotype.
b. A research of the whole layout of proteins which are coded by the same genome.
c. Comparing different proteins with different creatures in evolution.
7. Which of the following is true?
a. A somatic mutation is never hereditary.
b. A somatic mutation can be hereditary.
c. A mutation in the germ-line is always hereditary.
d. A mutation in the germ-line is never hereditary.
8. Which of the following describes the difference between exon and introns?
a. Exons are in the mature mRNA and introns aren’t.
b. Exons are coded for proteins and introns aren’t.
c. Exons are in the mature mRNA and introns in the pre mRNA.
d. Exons are displaces and introns aren’t.
9. Which of the following is related to differences in polymorphic sequences?
a. Never in a sequence coded for protein.
b. Can appear in sequences coded for protein but not influence the composition of its
amino acids.
c. Can appear in sequences coded for protein and influence the composition of its
amino acids but not its function.
d. Can appear in sequences coded for protein as well as influence the composition of
its amino acids and its function.
10. Which of the following is 3’UTR?
a. The sequence between the point of the beginning of the displacement and the
point of the beginning of the translation.
b. The sequence between the point of the end of the displacement and the point of
the end of the translation.
c. The sequence between the point of beginning of the displacement and the point of
the end of the displacement.
d. The sequence between the point of beginning of the translation and the point of the
end of the translation.
11. In which of the following cases, will you not perform a karyotype?
a. A baby with only a cleft palate.
b. A 17 y/o girl who didn’t receive a period.
c. A fetus, in which an amniotic fluid test has discovered a balanced chromosomal
translocation.
d. A baby with a large number of defects.
12. Please match the following tests with the corresponding people:
1. CVS a. A healthy 35 y/o woman in her 15th week of pregnancy.
2. Amniotomy b. A healthy 25 y/o woman who works in special care, first
pregnancy and concerned with down syndrome.
3. Ultrasound - system c. A woman in her 16th week of pregnancy with abnormal
survey. findings during a system survey.
4. Fetal protein test. d. A woman who has in a previous pregnancy a baby with
severe heart defects, abnormal joints and abnormal number of
fingers. Baby’s karyotype was normal.
5. Fetal blood test from e. A couple which both are CF carriers and there is a risk of the
the umbilical. disease in the family.
13. Please match the following:
1. 23,X a. Haploidy.
2. 69,XXX b. Aneuploidy.
3. 46,XX c. Tetraploidy.
4. 47,XY,21+ d. Triploidy.
5. 92,XXXX e. Diploidy.
14. Please match the following:
1. A phenomenon which happens in healthy males a. Genomic impression.
and not in healthy females.
2. A phenomenon which happens in healthy females b. Chromosome X inactivation.
and not in healthy males.
3. A phenomenon that causes a phenotypical mosaic c. Both.
in healthy individuals.
4. A phenomenon which causes random gene d. Neither.
inexpression from the paternal allele as well as the
maternal allele.
15. Please match the following:
1. Can be expressed in a normal cell of a a. Oncogenes or
healthy person. protoncogenes
2. Can be activated by translocation and b. Tumor
breaks. suppressors
3. Without their activity, the cell can c. Both.
easily become cancerous.
d. Neither.
16. The following is the process that determines the pigment in mouse fur: A colorless base
pigment is transformed to a colorless intermediate product by enzyme A, coded by gene
A. The intermediate product is transformed to a brown pigment by enzyme B, coded by
gene B. The brown pigment is transformed to a black pigment by enzyme C, coded by
gene C. The alleles of A,B and C are dominant. A crossbreeding experiment was
performed to the race of AABBCC, and then they crossbred F1 with themselves. Which
of the following would be the phenotype ratio in F2?
a. 9 black, 3 brown, 1 white.
b. 27 black, 9 brown, 28 white.
c. 13 black, 2 brown, 1 white.
d. 27 black, 9 brown, 3 white.
e. None of the above.
17. Which of the following is the maximum length of the chromosome 3 in humans, if you find
an average of 3.75 chiasmas per bivalent?
a. 3.75.
b. 375.
c. 1.875.
d. 187.5.
18. In a test crossbreeding of a BR/br fly, 84% of the meiosis have no chiasma, and 16% of
the meiosis have a single chiasma. Which if the following is the change to get a bbrr
offspring?
a. 4%.
b. 46%.
c. 16%.
d. 84%.
19. Rachel and Sarah, Jacob and Isaac are two sets of identical twins. Rachel marries Jacob,
Sarah marries Isaac. Each couple has a single child. The two children will be genetically
similar as which of the following?
a. Cousins.
b. Identical twins.
c. Siblings.
d. It is not possible to know.
20. In a specific chromosomal area, the correlation is more than 1. Which of the following is
the number of double recombinations in this area?
a. 0.
b. Lower than expected by the rate of unique recombinations in this area.
c. Higher than expected by the rate of unique recombinations in this area.
d. Equal to the expected by the rate of unique recombinations in this area.
21. A man and a woman who have the same genotype AaHHTkBb are married. Which of the
following is the probability that their first child will have an AaHHKKBB genotype?
a. 1/4.
b. 3/4.
c. 1/16.
d. 3/32.
e. 1/32.
22. In a woman the recombination rate between genes A and B is 8%, while in a man its 5%.
Which of the following is the chance to get an AABB offspring from a coupling of a man
and a woman, both of which are AaBb?
a. 4%.
b. 21.8%.
c. 25%.
d. 40%.
e. 92%.
23. In the gene Ee, a mutation (e) is causing a severe phenotype at the rate of 0.6 in its
homozygotic shape. Which of the following is the ratio of defected:healthy in an EexEe
crossbreeding?
a. 3:1.
b. 6:4.
c. 45:44.
d. 85:15.
e. 9:1.
24. 6% of all meiosis in AB genes in a mouse have recombinations. Which of the following is
the distance between genes A and B?
a. 6cM.
b. 12cM.
c. 30cM.
d. 2cM.
25. Which of the following is the distance between two genes with the same chromosome, in
which 6% of their meiosis have a chiasma?
a. 3cM.
b. 6cM.
c. 12cM.
d. 30cM.
26. What is polyadenylation?
27. What is the definition of genetic heterogeneity?
28. Which of the following is not required by a protein level genetic test?
a. Knowledge of the chromosomal location of the mutated coded gene.
b. Knowledge of the location of the mutated protein.
c. Knowledge of the biological activity of the mutated protein.
d. Existence of a biochemical test to measure the activity or level of the mutated
protein.
29. What does a cloning vector always include?
30. What is BAC?
31. Which of the following is true in relation to mitochondrial DNA?
a. It is similar to virus DNA.
b. It does not contain introns.
c. It is about 10% of total cellular DNA.
d. It has only 250 genes.
e. It is more stable than nuclear DNA.
32. Which of the following statements describes correctly a high resolution chromosomal
analysis?
a. You can identify genes that have only one copy.
b. Is performed at the end of the metaphase of cellular mitosis.
c. Can identify 400 light and dark stripes.
d. Is used to locate broken areas in the genes.
e. Can identify small structural changes in the chromosomes.
33. Which of the following describes a genetic mosaic?
a. DNA that is composed of 4 types of bases.
b. A chromosome composed of DNA and RNA.
c. A protein is created from information in at least two genes.
d. A protein system created from information in two genomes.
e. A gene that donates information to at least two proteins.
34. Which of the following statements best describes chromosomal changes in cancerous
growths?
a. Are usually unique and are characterized by the type of the growth.
b. These changes are usually in every cell in the body.
c. These changes usually disappear as the growth becomes more malignant.
d. The changes are usually different within each of the growth’s cells.
35. Hereditary colon cancer with no polyps is a great risk for the appearance of malignant
growths and is a dominant autosomal inheritance. Which of the following is not inherited
by people with it?
a. Activated Oncogen.
b. Immune deficiency disease.
c. Abnormal metabolism of carcinogenic substances.
d. Chromosomal aberration.
e. A defect in a DNA repair mechanism of the mismatch repair type.
36. The usage of drugs to effect changes in gene activity has become more popular lately.
An example is the administration of hydroxyurea to patients with sickle-cell anemia.
Which of the following describes the effect of hydroxyurea?
a. Stimulates the defected gene to work harder.
b. Repairs the mutation by causing a new mutation.
c. Activates a normally inactive gene.
d. Increases the amount of RNA.
e. Repairs the defected gene.
Genetics - 2003
1. Chickens with the genotype HhBb have been crossbred with chickens with the genotype
HHbb. Which of the following odds is that the offspring will be homozygotic in HB loci?
a. 30%.
b. 50%.
c. 23%.
d. 75%.
2. Which of the following is not true?
a. All vertebrates have an XY mechanism to determine sex.
b. Dosage-compensation exists in all creatures with heteromorphic chromosomes in
one of the sexes.
c. There is a mechanism of inactivation or hyperactivation in females.
d. a and b.
e. a and c.
f. a, b and c.
3. The following statements are given:
I. A recessive disease attached to the X passes from a sick father to his son.
II. A recessive autosomal disease passes from a sick father to his daughter and the
mother is not a carrier.
III. A recessive autosomal disease passes from a carrying father to his son and the
mother is not a carrier.
IV. A recessive autosomal disease passes from a carrying father to his daughter and
the mother is not a carrier.
Which of the above can be described by isodisomy?
a. All of them.
b. I.
c. I and II.
d. III and IV.
e. II, III and IV.
4. Which of the following is true in relation to the following diagram, and assuming an
attachment to chromosome X?
a. Subject 1-II exhibits a dominant disease.
b. 1-I and 2-II are carriers for the phenotype
observed in 1-II.
c. The probability that another offspring of 2-
II and 3-II will have the same phenotype of
1-III is 0.5.
d. If 1-II will marry a woman with an identical
phenotype of his sister, 75% of their
offspring is expected to have the same
phenotype as their aunt.
e. This family line does not correspond to a disease attached to the X.
5. In a crossbreeding between male and female fruit flies which seemed totally normal have
given the results of 68 males and 141 females. Which of the following is not true?
a. The number of offspring deviates from the expected in the male:female ratio.
b. The female is in a heterozygote crossbreeding to a lethal allele attached to the
sex.
c. The male is a heterozygote crossbreeding to a dominant allele of the same gene.
d. From the results you can conclude it is a pleiotropic gene.
6. Which of the following is the disease described in the given diagram?
a. Recessive autosomal.
b. Dominant autosomal.
c. Recessive attached to the X.
d. Dominant attached to the X.
7. A couple is heterozygote to a recessive mutation that causes albinism. The woman is
pregnant with unidentical twins. Which of the following is the probability both twins will
have the same pigmentation phenotype?
a. 0.625.
b. 0.375.
c. 0.25.
d. 0.75.
8. Which of the following is the disease described in the following diagram?
a. Recessive autosomal.
b. Dominant autosomal.
c. Recessive attached to the X.
d. Dominant attached to the X.
9. Which of the following is the disease described in the following diagram?
a. Recessive autosomal.
b. Dominant autosomal.
c. Recessive attached to the X.
d. Dominant attached to the X.
10. In a specific chromosomal area, the correlation is 0. Which of the following is the number
of recombinations in this area?
a. 0.
b. Lower than expected by the rate of unique recombinations in this area.
c. Higher than expected by the rate of unique recombinations in this area.
d. Equal to the expected by the rate of unique recombinations in this area.
11. A gene with codominant alleles controls feather color, so that fWfW is striped feathers, fBfB
is black feathers and fBfW is blue feathers. Another gene with partially dominant alleles
controls feather shape, so that MNMN is normal feathers, MNMF is slightly curled feathers
and MFMF is curled feathers. If we crossbreed birds with fBfW and MNMF, which of the
following would be the expected portion of offspring with black and curled feathers?
a. 1/4.
b. 1/16.
c. 3/16.
d. 9/16.
e. 1/9.
12. Allele A causes the appearance of yellow fur on rats (This allele is not lethal in
homozygotic state). Allele R causes the appearance of black fur on rats. A and R create
gray fur, while a and r create white fur. A gray male has been crossbred with a yellow
female. The following is the distribution of offspring by color in F1: 3/8 yellow, 3/8 gray,
1/8 white, 1/8 black. Which of the following was the parents’ genotype in this
crossbreeding?
a. AaRr x AaRr.
b. AARr x Aarr.
c. AaRr x Aarr.
d. AaRR x Aarr.
13. Which of the following is not true in relation to processed pseudogenes?
a. Contains only exon sequences.
b. Created only from reverse transcription.
c. Can contain a section of a gene.
d. Are usually transcribed.
14. In which of the following cases do you perform a pre-birth diagnosis inside the family, and
not by a direct analysis if the mutation?
a. The gene has not been cloned, but polymorphic markers next to it are known.
b. The gene is inherited attached to the X.
c. There is not sick relative still alive.
d. The biochemical test is more reliable than a DNA mutation test.
15. A family has members with a genetic disease. In order to determine the linkage of the
gene causing the disease to a specific chromosome locus, many CA-repeats sequences
have been tested. The following diagram shows the result for a specific polymorphic
marker, in which the numbers represent different alleles in the locus. Which of the
following is the LOD score of this family if you assume there is a 20% recombination
between the gene and the marker?
a. 2.62.
b. 0.418.
c. 0.04.
d. -1.38.
16. Which of the following is used as DNA fingerprints?
a. RFLP.
b. VNTR.
c. CA-repeats.
d. Alu sequences.
17. Which of the following is the length of 1cM (one centimorgan)?
a. 1 kilobase.
b. 10 kilobase.
c. 1 megabase.
d. 10 megabase.
18. The family represented in the following diagram has members with CF. There is an RFLP
next to the gene with 2 possible alleles of 7kbp and 5.5kbp. Which of the following can be
said about the daughter who isn’t sick?
a. She is definitely a carrier.
b. She is definitely not a carrier.
c. She has a 50% of being a carrier.
d. Unable to determine whether she is a carrier or not.
19. Which of the following is the use for the SSCP method?
a. Discovering small mutations.
b. Discovering mutations in dominant autosomal diseases only.
c. Observing amplification of trinucleoid repeats.
d. Screening of a population in order to discover mutations in PKU disease.
20. Which of the following qualities of fragile-X in helps discovery in the molecular method?
a. Abnormal methylation.
b. Unusually long protein.
c. Local mutation.
d. Expansion of the disease.
21. Which of the following is not a mechanism of metabolic diseases which harm the body?
a. Route product deficiency.
b. An increase in the concentration of a metabolite that is toxic to the cells.
c. An increase in the number of mutations because of changes in the genetic
sequence.
d. A decrease in energy creation.
e. Accumulation and storage of materials in the cells.
22. When a small number of individuals create a new population (a colony for example), the
number of alleles in the new population, is not necessarily equal to the number of alleles
in the parent population. Which of the following is the reason for this phenomenon?
a. Natural selection.
b. New mutations.
c. Selective breeding.
d. Bottleneck.
e. Genetic flow.
23. Which of the following is true in relation to genetic consultation tied to mitochondrial
chromosome mutations?
a. The severity of the fetal phenotype can be accurately diagnosed through testing
fetal cells in the amniotic fluid.
b. Mutations only pass from mother to daughter.
c. A mother with a mitochondrial chromosome mutation can pass it to her children,
but it does not express the disease itself.
d. The amount of infected mitochondria in the patient is the same as in his mother.
e. In homoplasy all the mitochondria are the same (infected or healthy).
24. Which of the following do not affect Bayes’ theorem?
a. Information coming from lab tests within the same family.
b. The age of an adult in case of a birth defect.
c. Information on the phenotype of a person’s brother.
d. Probability that comes from Mendelism.
e. Information about the frequency of a sick allele.
25. It is known that hip dislocation is from birth, passes in a multifactorial inheritance and is
more common in females. Which of the following is true, if a male was born with the
defect?
a. The recurrence rate in his brothers is higher than in his sisters.
b. The recurrence rate in 1st degree cousins is lower than in 2nd degree cousins.
c. The recurrence rate is higher in his sisters than in sisters of a female with the
defect.
d. The recurrence in brothers has no relation to the severity of the defect.
e. The recurrence in brothers is twice as that of the general population.
26. Which of the following is not used to research multifactorian inheritance?
a. Family studies.
b. Twins studies.
c. Determining cDNA sequences.
d. Adopted children studies.
e. Population studies.
27. Which of the following strategies for dealing with genes is not possible or legitimate?
a. Repairing defective genes in sick cells that were removed, repaired and replaced.
b. Changing a defective gene in the body with a non viral vector.
c. Adding a healthy gene with a viral vector.
d. Cloning a new baby from one cell of the sick baby.
e. Removing sick cells from the patient, repairing them in a lab and replacing them.
28. There are two probabilities of an outcome of an event, p and q (p≠q). Which of the
following is the probability of either event happening?
a. pxq.
b. p2+q2.
c. (p+q)/2
d. p+q.
e. 2pq.
29. Which of the following is true in relation to MZ:DZ?
a. MZ>DZ - dominant inheritance.
b. MZ>DZ - recessive, autosomal inheritance.
c. MZ=DZ - cannot be multifactorial inheritance.
d. MZ>DZ - if MZ=100%, then the type of inheritance depends on DZ.
30. Which of the following is the definition of “Regressing to the average”?
a. Parents far from the average will have children ever further from the average.
b. Parents far from the average will have children closer to the average.
c. In a multifactorial inheritance the disease is caused by the mutation average in
the different genes.
31. Which of the following is true in relation to mitochondrial inheritance?
a. Each cell has the same number of mitochondria.
b. The number of mitochondria is constant.
c. The number of chromosomes of mtDNA in each mitochondrion is constant.
d. The number of mitochondria in a cell has no biological or medical meaning.
e. The phenotype appears when the number of infected mitochondria falls below the
biological limit (not enough energy to sustain the cell).
32. The Hardy Weinberg law relates to a population that has random coupling with no
preference in relation to the phenotype. Which of the following deviates from random
coupling?
a. Extra marital coupling.
b. Polygamist marriage.
c. The tendency of an intelligent man to marry an intelligent woman.
d. Lifelong marriage with no divorce.
e. IVF with an anonymous sperm donor.
33. Which of the following is not suitably detected by FISH technique?
a. Isochromosome.
b. Minute deficiencies.
c. UPD.
d. Reciprocal translocations.
e. None of the above.
34. During a FISH test for retinoblastoma, while using a detector for 13-q14, it was found that
growth cells have no signals and blood cells have 2 signals. Which of the following
conclusions is true?
a. It is 100% certain that the patient will have defected children because the
mutation is in all growth cells at a double amount.
b. A great chance for healthy children.
c. Parents have a 50% chance in every additional pregnancy for a defected child.
d. a and c.
e. None of the above.
35. Which of the following women who have sought genetical consultation have the highest
risk of birthing a child with Down syndrome?
a. A mother with the karyotype 45,XX, -14 -21, +t(14q, 21q).
b. A 33 y/o mother after giving birth to a child with Down syndrome in the previous
pregnancy.
c. A 41 y/o mother.
d. A mother with the karyotype 45,XY, -14 -21, +t(14q, 21q).
36. Which of the following is represented by androgenital syndrome?
a. Hermaphroditism.
b. Male pseudo-hermaphroditism.
c. Feale pseudo-hermaphroditism.
d. None of the above.
37. Which of the following is not true in relation to the karyotype 49,XXXXY, discovered
during a chromosomal analysis?
a. There is a high risk of retardation.
b. Males with this have a high chance to give birth to a female with the karyotype
47,XXX.
c. Outer sex organs are male.
d. These cases are more common than Kleinfelter syndrome cases with the
karyotype 47,XXY.
e. Chromatin is positive like in a female with the karyotype 48,XXXX.
38. Which of the following is not an aneuploidy?
a. Monosomy.
b. Triploidy.
c. 47,XXX.
d. 48,XXYY
e. Polyploidy.
f. b and e.
39. In which of the following is the cancerous process a part of an oncogene activation?
a. Burkit’s lymphoma.
b. Leukemia.
c. Retinoblastoma.
d. Fancony.
e. a and c.
f. b and c.
Possible Answers:
1 - d, 2 - c, 3 - e, 4 - b, 5 - c, 6 - a, 7 - b, 8 - b, 9 - b, 10 - d, 11 - b, 12 - c, 14 - a, 15 - b, 17 - c,
18 - a, 20 - d, 21 - c, 22 - d, 23 - e, 24 - b, 25 - c, 26 - c, 27 - d, 28 - d, 29 - d, 30 - b, 31 - e,
32 - b, 33 - e, 34 - b, 35 - b, 37 - d, 38 - f, 39 - b.
Genetics - 2002
1. A spontaneous mutation that causes a golden fur color (As opposed to the natural gray)
has appeared in a breeding farm. The breeders tried to create a purely golden breed, but
every second crossbreeding brought gray and golden colored offspring. Which of the
following might explain the above?
a. The mutation that caused the golden color is dominant and attached to the X.
b. The mutation that caused the golden color is recessive and attached to the X.
c. The mutation that caused the golden color is lethal recessive.
d. The mutation that caused the golden color is partially dominant.
2. In a test crossbreeding of a BR/br fly, 84% of the meiosis have no chiasma, and 16% of
the meiosis have a single chiasma. Which if the following is the change to get a bbrr
offspring?
a. 50%.
b. 4%.
c. 84%.
d. 25%.
e. 16%.
3. A dihybrid cross test MmSsCc has given the following results:
MSC - 74; msc - 65; Msc - 255; mSC - 288; MSc - 147; msC - 125; MsC - 26;
mSc - 20. A total of 1000. Which of the following is the distance from C to M?
a. 31.8cM.
b. 18.5cM.
c. 13.9cM.
d. 46cM.
4. Which of the following is not true in relation to multifactorial inheritance?
a. The chance a person is born with a defect or a disease increases with the amount
of cases in the family.
b. The chance a person is born with a defect or a disease increases with the
immediate relation to the first one who is sick.
c. The chance a person will be born with the same multifactorial defect/disease as his
brother equals to the square of the rate of the defect/disease in the general
population.
d. The chance a person is born with a defect or a disease increases with the severity
of the defect/disease in other relatives.
e. The chance of a brother born with the same defect/disease increases if the
defect/disease afflicting the individual is rarer in the individual’s sex.
5. Which of the following is the distance in cM between two genes on both sides of a
chiasma?
a. 1.
b. 50.
c. 100.
d. Unable to determine.
6. Which of the following is the difference between mtDNA and nDNA?
a. mtDNA genetic code is more similar to a germ and less similar to nDNA.
b. In the nucleus the DNA is coded to tRNA and in the mitochondria its not.
c. The nDNA has 4 bases while the mtDNA has 5.
d. The nDNA has two strips, while the mtDNA has only one.
7. In a population the phenotype Dom/Dom has been crossbred, and the recessive offspring
ratio was X. In a Rec/Rec crossbreeding, the ratio was Y. Which of the following is the
correct equation?
a. X=Y2.
b. Y=X2.
c. X2=Y2.
d. None of the above.
8. Which of the following helps determine the gene sequence in? (Incomplete question)
a. Protein methylation.
b. Abnormal protein.
c. Irregular splicing.
d. Gene expansion.
9. A grandmother carrying testicular feminization wishes to test her granddaughter’s for the
chance she is carrying as well. Which of the following would be the test’s results?
a. Not a carrier.
b. Definite carrier.
c. 50% chance of carrying.
d. Unable to determine without a karyotype from the mother.
10. Which of the following sequences would prove you have a part of a gene if you hybridize
them with a sequence of DNA critical from a critical locus?
a. Alu-repeats.
b. CA-repeats.
c. EST.
d. VNTR.
11. Galactosemia is a recessive, autosomal disease. A woman whose father had the disease
marries a man whose grandfather had the disease. Which of the following odds is the
probability their child will also carry the disease?
a. 1/4.
b. 1/32.
c. 1/16.
d. 1/8.
12. Which of the following cells might have mutations?
a. Somatic cells in an adult.
b. Somatic cells in a fetus.
c. Somatic cells in an adult, fetus and gamete.
d. None of the above.
13. Which of the following does not express a defect in the metabolism of a vitamin?
a. Apoenzyme becomes holoenzyme more efficiently.
b. A disturbance in the function of two or more enzymes.
c. A possible decrease of intra-cellular active enzyme form concentration.
d. Administering a high dosage of the vitamin might be an effective treatment.
e. A possible appearance of pathogenic metabolites in a number of routes in the
body’s fluids.
14. In the drosophila (“fruit flies”) the recessive allele s causes the appearance of short wings,
and S causes normal length wings. Gene S is attached to the X. A short winged male
and a normal winged homozygotic female are crossbred. Which of the following is the
expected ratio between short and normal winged offspring?
a. All males will have short wings, and all females will have normal wings.
b. All females will have normal wings, while the males will have a 50%/50%
distribution between short and normal wings.
c. All males will have normal wings, while the females will have a 50%/50%
distribution between short and normal wings.
d. All males and females will have normal wings.
Please match questions 15-18 with their correct definition:
15. Turner syndrome. a. Uniparental disomy.
16. 47,XXX. b. Deletion
17. Cri Du Chat syndrome. c. Trisomy
18. Prader Willi syndrome. d. Insertion.
e. Monosomy.
f. Triploidy.
g. a and b
19. Allele A causes the appearance of yellow fur on rats (This allele is not lethal in
homozygotic state). Allele R causes the appearance of black fur on rats. A and R create
gray fur, while a and r create white fur. A gray male has been crossbred with a yellow
female. The following is the distribution of offspring by color in F1: 3/8 yellow, 3/8 gray,
1/8 white, 1/8 black. Which of the following was the parents’ genotype in this
crossbreeding?
a. AARr x Aarr.
b. AaRR x Aarr.
c. AaRr x Aarr.
d. aarr x Aarr.
20. In a recessively hereditary disease, the frequency of sick people is 1/10,000. Which of
the following is the frequency of heterozygotes?
a. 1/50.
b. 1/5000.
c. 1/200.
d. 1/100.
21. In which of the following can a metabolic disease not harm the body?
a. The substrate accumulates and is toxic to other enzymes.
b. The substrate accumulates and is stored in cellular organelles in a constantly
progressive way.
c. A metabolic route product is missing because of no production.
d. Energy creation deficiency because of harm to the mitochondria.
e. Substrate deficiency does not allow energy creation.
22. A girl with fragile-X syndrome also has Turner syndrome. From which parent is it most
likely that she received a chromosomally irregular gamete?
a. The father.
b. The mother.
c. The guy who is translating this test. (I sure hope not!)
d. There is not enough information to answer the question.
e. She has received two regular gametes and lost the maternal chromosome during
fetal development.
23. A woman has in the androgen receptor gene (In which an amplification mutation causes
Kennedy disease) two tri-nucleotide sequenced alleles: One of 15 repetitions and one of
21 repetitions. This woman has a cancerous growth in the organ which this gene
expresses. You can isolate single cells from the growth and examine them molecularly to
determine their repeat length. Which of the following would be the results from that test?
a. The PCR will have 2 alleles while the RT-PCR will have only one.
b. Both samples will have 2 alleles.
c. Both samples will have a single allele.
d. The PCR will have a single allele while the RT-PCR will have 2.
24. Linkage is tested between a polymorphism in an α-globin gene, and a dominant
autosomal disease called PKD. The linkage was tested among families in England and
Holland, and the following results were given:
θ 0.01 0.1 0.2 0.3 0.4
LOD Score 23.4 24.6 19.5 12.85 5.5
Which of the following is the most likely in relation to the above information?
a. There is no linkage; they could be on different chromosomes.
b. They are so closely linked they have no recombination.
c. They have a 10cM linkage.
d. They have a 0.4cM linkage.
25. This question relates to the above:
A family from Sicily has the same disease (PKD), and the following results were given:
θ 0.01 0.1 0.2 0.3 0.4
LOD Score -10.23 -8.34 -3.34 -1.05 -0.02
Which of the following can be told considering the above?
a. This family has no PKD.
b. The disease is heterogenic.
c. In Sicily there’s a linkage between α-globin and the PKD gene from the other side
of the chromosome.
d. If more families are diagnosed with positive PKD, the LOD Score would be positive.
Questions 26 and 27 are diagrams. Please match them with the most likely definition of a family
with a rare disease in the population:
26.
27.
a. Recessive autosomal.
b. Dominant autosomal.
c. Recessive attached to the X.
d. Dominant attached to the X.
28. During a project, CDNA shows RFLP. It is suspected that this is a CDNA of gene in a
recessive autosomal disease. An analysis of the family with the disease shows the
following diagram:
Which of the following would be the conclusion?
a. The results support that this is a gene of the disease, but it is not completely
proven.
b. The tested gene is definitely the disease’s gene.
c. The tested gene is definitely not the disease’s gene.
d. The results do not help reach a conclusion.
Possible Answers:
1 - c, 3 - b, 4 - c, 5 - d, 6 - a, 11 - c, 12 - c, 13 - a, 14 - d, 15 - e, 16 - c, 17 - b, 18 - g, 19 - c,
20 - a, 22 - b, 24 - c, 25 - b, 28 - a.