GENETICS MCQ
1.
Best way to differentiate between homocvstinuria and Marfan’s syndrome?
a.
b.
c.
d.
e.
lens ectopia
long arms
autosomal dominant
lack of thrombosis
mental retardation
2.
Which DNA screening test is the most useful:
a.
b.
c.
d.
CFTR F508
Prenatal determination of gender
Screening Mediterranean people for thalassaemia
Familial adenomatous polyposis coli
3.
Prior to genetic testing for Huntington's disease which of the following must be performed first:
a.
b.
c.
d.
e.
Examination
History taking
CT head
EEG
Genetic counseling
4.
What best describes microsatellites:
a.
b.
c.
Areas of genomic instability
Tandem repeats of up to six base pairs
RFLPs
5.
Which is the most common laboratory finding in -thalassaemia carrier (trait):
a.
b.
c.
d.
e.
Mild microcytic anaemia
Gene deletion
Point mutation
Translocation
Macrocytic anaemia
6.
In which of the following is the most commonly identified hereditary defect leading to the development of
diabetes:
a.
b.
c.
d.
Glucose transporter
Glucokinase gene
Insulin receptor
Insulin
7.
DNA imprinting is best described by:
a.
b.
c.
d.
e.
Effect of parental gender gene origin on transmission of disease
Differential methylation of other allele
Altered DNA promoter region
( Maternal option)
(Paternal option)
8.
Some psychiatric disorders such as schizophrenia are thought to have a genetic basis. The strongest supportive
evidence for this is:
a.
b.
c.
d.
HLA association
Monozygotic concordance
Dizygotic concordance
Family clustering
9.
Which of the following is less likely to be found in an example of an X-linked genetic disorder such as
haemophilia?
a.
b.
c.
d.
e.
male to male transmission
female to female transmission
consanguinity
skipping of generations
germinal mosaicism
10.
Potential problems in the RFLP analysis
a.
b.
c.
d.
e.
non-paternity
cross over between linked genes - non predictable
not knowing the exact base sequence of the gene (i e. DNA sequence)
need family study
need to know gene is causative (?need to know causative gene)
11.
A child has a rare autosomal recessive condition but only 1 parent is found to be a carrier. This can be
explained by
a.
b.
c.
d.
e.
uniparental disomy
non-paternity
germline mosaicism
mitochondrial inheritance
incomplete penetrance
12.
In situ hybridisation:
a.
b.
c.
to detect rnRNA for protein products
detect location of mRNA in cell
method is as sensitive as immunofluorescence methods
13.
Concerning mitochondrial DNA:
a.
b.
c.
d.
e.
deletions have been demonstrated in human diseases
codes for parts of mitochondrial enzymes
originates in cell nucleus
exhibits RFLP
familial pathogenic mutations are always of maternal origin
14.
With respect to mRNA, it can be determined by:
a.
b.
c.
d.
e.
Southern blot
in-situ hybridisation with labelled oligonucleotides
Northern blot
PCR
in-situ hybridisation with labelled DNA probes
15.
Which of the following is/are true of genes?
a.
b.
c.
d.
e.
Mitochondrial genes are all maternally derived
Splicing of introns occurs in mRNA
Less than 10% of DNA is translated
Oncogenes are normal components of human DNA
Oncogenes are activated by the process of chromosomal translocation
16.
Which of the following is/are true of genetic linkage?
a.
b.
c.
d.
e.
A low lod score indicates linkage of two genes
It is distinct from association
Autosomal crossovers are equally frequent in males and females
Linked gene loci are sometimes on different chromosomes
Linkage disequilibrium is used in DNA diagnosis
17.
Which of the following diseases can be diagnosed prenatally by DNA diagnostic tests?
a.
b.
c.
d.
e.
Duchenne muscular dystrophy
Cystic fibrosis
Sturge-Weber syndrome
Haemophiha A
Polycystic kidney disease
18.
Which of the following is/are true of autosomal recessive disorders?
a.
b.
c.
All offspring of two individuals with autosomal recessive disorder will be affected
Genetic counselling for members of affected families is based on the assumption that mutation rates are high
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19.
Both parents heterozygotes for Cystic Fibrosis gene. They have 4 children. Which of the following are true:
a.
b.
c.
d.
e.
The chance that no children will be affected is the same as that all children will be affected
The probability that no children will be affected is < 5%
The most likely outcome is one affected child
The chance of 4 affected children is <1%
The risk of 2 affected children is greater than the risk of no affected children
20.
Concerning inheritance, which associations are true?
a.
b.
c.
d.
e.
Paternal and mitochondrial
Gene mosaicism and recurrence of disease in a farnily
Phenotypic variation and somatic mosaicism
Inactivation of one parental allele & imprinting
Development of autosomal recessive disorder with one carrier parent & uniparental disomy