Basic Medical College of Fudan University
Final Exam of Medical Genetics in 2014-2015 (1)
MBBS
□B
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A. Multiple choice questions (select the single correct answer)( 20%)
1. Autism is a neurodevelopmental disorder characterized by impaired social
interaction, communication capabilities, and restricted behavior. What is the cause of
Autism?
A. Genetic factors
B. Environmental factors
C. Epigenetic factors
D. None of the above
E. All the above
2. Chromosome aberration characterized by missing, extra, or irregular portion of
chromosomal DNA, is the primary cause of numerous genetic defects. Which of the
following genetic defects is not caused by chromosome aberration?
A. Jacobsen syndrome
B. Marfan Syndrome
C. Turner Syndrome
D. Down syndrome
E. Klinefelter syndrome
3. Neural tube defects (NTDs) are one of the most common birth defects, affecting
over 300,000 births globally each year. Which of the following diseases is not a
neural tube defect?
A. Spina Bifida occulta
B. Meningocele
C. Anencephaly
D. Polymelia
E. Iniencephaly
4. Marfan syndrome is a genetic disorder of human connective tissue. Which gene
has been found to be associated with the Pathogenesis of Marfan Syndrome?
A. FBN1
B. SHH
C. MAPK14
D. PITX1
E. ERK2
5. Each of the following have been observed as mechanisms resulting in the activation
of a proto-oncogene EXCEPT:
A. Amplification of an oncogene as small, sub-chromosomal fragments (double
minutes)
B. Capture of the oncogene sequence by a retrovirus
C. A point mutation altering the function of the oncogene protein product
D. Inactivation of an oncogene by telomerase activity
E. A chromosome translocation fusing portions of the oncogene and another cellular
gene
6. Patients with familial retinoblastoma carry a germline mutation in one copy of
the Rb gene. Potential mechanisms for inactivation of the other allele in a
retinoblastoma tumor arising in one of these patients include:
A. An independent point mutation
B. Loss of the normal chromosome 13
C. Mitotic crossing over
D. All of the above
E. None of the above
7. The functions which have been identified for the proteins expressed by cellular
proto-oncogenes include all of the following EXCEPT:
A. enzyme involved in DNA mismatch repair
B. transcription factor
C. growth factor
D. component of a signal transduction pathway
E. growth factor receptor
8. Which of the following is a false statement?
A.Most SNPs have only two alleles.
B.Microsatellites and minisatellites usually have many alleles.
C. Microsatellites are often used as genetic markers in pedigree-based linkage studies.
D. SNPs are often used for genetic finger printing of forensic DNA samples.
E. SNPs are often used as genetic markers in genomewide association studies.
9. Which of the following statements is false?
A. Haplotypes are ordered sequences of genotypes
B. Haplotypes are ordered sequences of alleles.
C. There are fewer haplotypes in human populations than the theoretical maximum.
D. The paucity of haplotypes in human populations reflects the relative “youth” of
these populations.
E.The linkage disequilibrium constant D’ provides a quantitative measure for the
tendency of certain alleles to be inherited together from generation to generation.
10. Which of the following statements is false?
A.The mathematical equation for Hardy-Weinberg equilibrium (HWE) is: p2 + 2pq +
q2 = 1
B. The mathematical equation for Hardy-Weinberg equilibrium (HWE) is: p + 2pq +
q=1
C.The HWE equation is useful for estimating the frequency of heterozygous carriers
of a mutation that causes a recessive Mendelian disorder.
D. Assumptions that must be met for alleles to be in HWE include:large population,
random mating, no new mutations, 2 alleles.
11. Which of the following is a false statement?
A. Somatic cells each contain roughly 200 -2000 mitochondria.
B.Mitochondria carry out many important cellular functions, including the production
of ATP, oxidation of fatty acids, regulation of intracellular Ca2+ levels and regulation
of apoptosis.
C.Mitochondria are also the source of beneficial free radicals.
D.Sperm contain approximately 100 mitochondria and oocytes approximately
100,000 mitochondria.
E.All of our cells contain mitochondria inherited exclusively from our mother.
12. Which of the following cannot be explained by abnormal recombination?
A. Robersonian translocations
B.unbalanced translocations
E. inversions
D. deletions
E. point mutations
13. Which of the following is a true statement?
A. Chromosomal non-disjunction occurs during mitosis only in females.
B.Chromosomal non-disjunction occurs during mitosis only in males.
C.Chromosomal non-disjunction occurs during meiosis only in females.
D. Chromosomal non-disjunction occurs during meiosis only in males.
E. Chromosomal non-disjunction occurs during meiosis in both males and females.
14. Which of the following comprises the smallest percentage of human nuclear
genome?
A.RNA genes
B. heterochromatin
C.retroviral/transposon-derived sequences
D.proteincoding sequences
E.other sequences
15. Which of following is not at correct match between the named individual named
and listed contribution to genetics?
A.Gregor Mendel: discovered simple patterns of inheritance of discrete traits
B. Archibald Garrod: first to describe the pattern inheritance of recessive diseases in
humans
C.Thomas Hunt Morgan: discovered that genes reside within DNA
D.Linus Pauling: the first to identify the molecular cause of human genetic disease
E.Ronald Fisher: showed that the inheritance of continuous human traits can be
explained in
terms of the inheritance of multiple discrete factors (genes)
16. Which of the following is an incorrect matching between the named disease and
listed mode of inheritance?
A. Neurofibromatosis: autosomal dominant
B. cystic fibrosis: autosomal recessive
C.ABO blood types: co-dominant
D.Acondroplasia: X chromosome-linked
E.Azoospermia: Y chromosome-linked
17. Which of the following statements is false?
A. Recently genetic studies have provided strong evidence that all current human
populations derive from a small group of individuals who migrated out of Africa
roughly 60 -70 thousand years ago.
B. Previously, it was thought that current human populations comprised the
descendants of independent groups of archaic humans (hominids) who left Africa
several hundred thousand to one million years ago.
C. There is no evidence that the ancestors of modern humans (homo sapiens) mated
with archaic humans, such as Neanderthals.
D.The current African population is collectively much “older” than populations in
other parts of the world.
18. Which of the following is a false statement?
A. Mitochondria are believed to have evolved from free living bacteria-like organisms
during the last ~1.5 billion years.
B. The mitochondrial “Eve” is thought to have lived in Africa ~ 200 million years
ago.
C. Analysis of mitochondria DNA has provided crucial evidence for the “Out of
Africa”theory of the origins of current human populations.
D.Mitochondrial DNA is also useful for tracing more recent maternal lines of decent.
E.The mutation rate of mitochondria DNA is much higher than that of nuclear DNA.
19. Which of the following is a false statement?
A.Symptoms of mitochondria diseases include fatigue, muscle weakness, neurological
disorders, problems with vision or hearing, problems with the heart, liver, kidney,
endocrineglands orbowels.
B. The pattern of inheritance of mitochondrial disorders resemblesa pattern of
inheritance of observed among Mendelian disorders.
C. Homoplasmy refers to situation where all mitochondrial in the cell are genetically
identical with respect to a specific mutation in the mitochondrial genome (i.e., all the
mitochondria in the cell are defective or normal with respect to the mutation).
D. Heteroplasmy refers to the situation where there is a mixture of defective and
normal mitochondria in a cell.
20. Which of the following diseases has not been proposed to be caused by mutations
under positive selection due to “heterozygote advantage” for resistance to an
infectious disease?
A. sickle-cell anemia
B. thalassemia
C.cystic fibrosis
D. neurofibromatosis
E. glucose-6-phosphate dehydrogenase deficiency
B. Terminology and Short answer questions(40%)
1.Ventricular Septal Defect
2.Cleft Lip
3.Benign and Malignant Tumor
4.Prion Disease
5.X Chromosome inactivation
6.Cystic fibrosis
7. Describe the principles of X-linked inheritance
8. Chromosome Nondisjunction
C. Long answer questions(60%)
1. Cancer is a genetic disease, or more precisely, cancer arises from malfunction of
genes. List the three categories of cancer genes and explain how they cooperate to
initiate and promote tumorigenesis.
2. What are the major differences between birth defects and birth injuries?
3. Mr A , and his wife, has two children: a boy (5 years old) with Down syndrome and
a girl(2 years old with PKU). Now they hope to have a healthy baby, please give them
some suggestion.
4. Explain why Angelman syndrome and Prader-willi syndrome can result from both
uniparental disomy and microdeletion .
5. What is the difference between a loss of function mutation and a gain of function
mutation? Give an example.