Genetics - Practice Questions Flashcards
Polydactyly (extra finger) is a dominant trait in humans. a person who has polydactyly has parents who do not have polydactyly and a maternal grandfather who does have polydactyly. what is the most likely explanation for this?
A.) Codominance
B.) Incomplete Dominance
C.) Incomplete Penetrance
D.) Environmental Effect
E.) Variable Expressivity
C.) Incomplete Penetrance
Which of the following defines the pseudoautosomal region?
A.) Regions of X and Y chromosomes that dont recombine in meiosis
B.) Hemizygoud regions of X and Y chromosomes
C.) Heterozygous regions of X and Y chromosomes
D.) Homologous regions of X and Y chromosomes
E.) Homozygous regions of X and Y chromosomes
D.) Homologous regions of X and Y chromosomes
Myotonic dystrophy may show increasing severity and earlier age of presentation in successive generations. This phenomenon is known as:
A.) Compound Heterozygosity
B.) Anticipation
C.) Incomplete Penetrance
D.) Variable Expressivity
E.) Locus heterozygosity
B.) Anticipation
Hemophillia A and B have nearly identical phenotypes, but they result from mutations in different genes on the X chromosome. This is an example of:
A.) Allelic Heterogeneity
B.) Variable Expressivity
C.) Complex heterozygosity
D.) Double heterozygosity
E.) Locus heterozygosity
E.) Locus heterozygosity
Cystic fibrosis mutation screen of an affected child reveals that he carries the delta F508 mutation on one chromosome and the G551D mutation on the other choromosome
A.) Compound heterozygosity
B.) Plieotropy
C.) Lyonization
D.) Allelic heterozygosity
E.) Locus heterozygosity
A.) Compound heterozygosity
In a Population expressing five different allels for a particular gene, how many alleles may be present in each diploid organism in the population?
A.) 1
B.) 2
C.) 3
D.) 4
E.) 5
B.) 2
Polyploidy refers to:
A.) an individual with complete extra set of chromosomes
B.) extra copies of a gene adjacent to each other on a chromosome
C.) a chromosome whivh has replicated but not divided
D.) several duplications of a gene adjacent to each other
E.) an individual with extra-copies of a chromosome
A.) an individual with complete extra set of chromosomes
If you examine a pedigree showing the transmission patteren of mitochondrial gene mutation, which of the following statements would be FALSE?
A.) Fathers do no transmit the gene
B.) Only females will express the trait
C.) mothers pass the gene to all sons
D.) mothers pass the gene to all daughters
E.) mothers pass the gene to all offsprings
B.) Only females will express the trait
(The FALSE one)
Duchenne Muscular Dystrophy and Becker muscular dystrophy have different phenotype, but they result from mutations in the same gene. this is an example of:
A.) Pleiotrophy
B.) Locus heterogeneity
C.) Allelic heterogeneity
D.) Variable Expressivity
E.) Compound Heterozygosity
C.) Allelic heterogeneity
In people with sickle cell disease the RBCs breakdown, clumo and clog vessels. These accumulate in the spleen and also lead to physical weakness, heart failure, pain, brain damage and spleen damage. Affected individuals become paralyzed and can develop rheumatism, pneumonia and other diseases and kidney failure. This is the example of :
A.) Polygenic nature of Sickle cell disease
B.) Pleiotropic nature of Sickle cell disease
C.) Interaction between the sickle cell allele and proteolytic enzyme gene
D.) infectious organisms acting on sickle cell allele
B.) Pleiotropic nature of Sickle cell disease
A person with two or more different cell lines originating from a single zygote is called a:
A.) Syndrome
B.) Chimera
C.) Pleiotropy
D.) Mosaic
E.) Heterozygote
D.) Mosaic
What is true for the chromosomes?
A.) DNA sequence of the two sister chromatids are similar
B.) one of the sister chromatids of a chromosome is of maternal and other is of paternal origin
C.) the two sister chromatids are bound by kinetochore region
D.) DNA sequence of the two sister chromatids are identical
E.) DNA sequence of the two sister chromatids are different
D.) DNA sequence of the two sister chromatids are identical
Which one of these is caused by repeats of base triplets rather than a whole chromosome?
A.) Down syndrome
B.) Edwards Syndrome
C.) Klinfelter Syndrome
D.) Fragile-X Syndrome
D.) Turner Syndrome
D.) Fragile-X Syndrome
DNA fingerprinting is possible because:
A.) Individuals, except identical (monozygotic) twins, are unique
B.) Different restriction enzyme is needed to cut different person’s DNA
C.) Each person’s DNA uses different type of bases
D.) individuals are grown up in diff. environment
E.) each person has a unique set of genes
E.) each person has a unique set of genes
Anaphase II:
A.) Homologous seperate and migrate towrds opposite poles
B.) sister chromotids seperate and migrate towrds opposite poles
C.) Nuclei reform
D.) chromosomes lone up in the equator of the cell
E.) the cells are diploid
B.) sister chromotids seperate and migrate towrds opposite poles
What is the sex of the subject that has this karyogram?
Female
Is there any disorder in subject that has this karyogram?
If yes, what is it ?
Yes,
Aneuploidy, Chromosome 7 Trisomy
Which chromosomes can be involved in that kind of mutation ? (Like in the karyogram)
Any chromosome
Give the official description of this karyogram
47 ,XX + 7 Trisomy
What is the sex of the subject with this Karyogram?
XX , Female
Does the subject with this Karyogram has any health problems? Specify.
No, There is a robertosonian translocation of c 15 to c 14, but there is no duplication of deletion of genetic material. Aka Centric Fusion.
Which chromosomes can be involved in this kind of mutation?
Centric Fusion -Occurs in Acrocentric Chromosomes:
13, 14, 15, 21, 22
What is the official description of the presented anomaly?
45, XX (t:14, 15) (Robertsonian translocation)
mode of inheritance
Autosomal Ressecive
Who are heterozygous?
Heterozygous: III:2, III:3, II:1, II:4, I:1, I:2
(This is in case of AR disorder)
Give 3 examples for the inheritance pattern shown in the pedigree
- Cystic Fibrosis
- Tay–Sachs
- Sickele cell disease
What is it : the severity of the ilness can often vary in the affected persons even suffering from the very same variant.
A.) Pleiotrophy
B.) Locus heterogeneity
C.) Phenocopy
D.) Variable Expressivity
E.) Complete Penetrance
D.) Variable Expressivity
In a group of 100 women with the genotype for widow’s peak in the hairline, only 87 actually exhibite the trait. This is an example of :
A.) Variable Expressivity
B.) Incomplete Penetrance
C.) Anticipation
D.) Heterogeneity
E.) Pleiotropy
B.) Incomplete Penetrance
Which of the following syndrome is a associated with Paternal Disomy for chromosome 15?
A.) Beckwith-Wiedemann syndrome
B.) Hydatidiform Mole
C.) Prader-willi syndrome
D.) Klinefelter’s syndrome
E.) Angelman syndrome
E.) Angelman syndrome
Which of the following identifies NOT correctly the mose of inheritance of a given genetic disease?
A.) G6PD - XR
B.) Familial Hypercholesterolemia- AD
C.) Tay-Sachs - AR
D.) High Blood pressure - Multifactorial
E.) Phenylketouria - XR
E.) Phenylketouria - X-Linked Recessive
(It is actually AR)
What is it: different allelic combination lead to similar phenotypes?
A.) Phenocopy
B.) Complete Penetrance
C.) Allelic Heterogeniety
D.) Pleiotropy
E.) Expressivity
C.) Allelic Heterogeniety
Marfan syndrome, AD, single gene defect is characterised by lens dislocation, long limbs, spindly fingers and caved -in-chest and weakend aorta. this is an example of:
A.) Phenocopy
B.) Complete Penetrance
C.) Allelic Heterogeniety
D.) Pleiotropy
E.) Expressivity
D.) Pleiotropy
Some mutations have been found that are expressed differently depending on the sex of the parent the gene is passed through. This is called:
A.) Incomplete Penetrance
B.) Complete Penetrance
C.) Imprinting
D.) Sex linked inheritance
E.) Sex limited inheritance
C.) Imprinting
Which statement is NOT true about X and Y chromosomes?
A.) Sex determination is based on them.
B.) Pseudoautosomal regions are found both on X and Y.
C.) During male meiosis X and Y chromosomes pair by their short arm.
D.) In rare instances SRY is also involved in genetic recombination XX male and XY females.
E.) Most of X and Y chromosome located genes are related to gonadal and genital development.
E.) Most of X and Y chromosome located genes are related to gonadal and genital development.
A man with type A blood marries a women with type B blood. If both parents homozygous, their offspring will have type ___ blood, which is an example of:
A.) O; Recessiveness
B.) AB; Incomplete dominace
C.) AB; Codominance
D.) B; Dominance of B over A
E.) A; Dominance of A over B
C.) AB; Codominance
Huntington’s Disease is an example of genetic disorder caused by:
A.) homozygous recessive alleles
B.) a late acting recessive allele
C.) a late acting dominant allele
D.) a non-lethal dominant allele
E.) multiple alleles
C.) a late acting dominant allele
Which modes of inheritance are possible in this pedigree ?
AR
Examples for the same Mode of Inheritance
Vit-D resistant Hypophosphatemia, Fragile-X syndrome, Amelogenesis Imprefecta
Mode of Inheritance
XD
Mode of Inheritance
AD
What is the name of the chromosomal abberation in 1) ?
1) Interstitial Deletion
What is the name of the chromosomal abberation in 2) ?
2) Duplication
What is the name of the chromosomal abberation in 3) ?
3) Paracentral Inversion
What is the name of the chromosomal abberation in 4) ?
4) Reciprocal Translocation
Chromosomal Aberration (Official Description)
69, XXY, (Triploidy with Klinefeleter syndrome)
Mode of Inheritance
XD
What is the method used here? Define
Gel Electrophoresis - RFLP
A polymorphic difference in DNA sequence between individuals that can be recognized by restriction endonucleases.
The Original was: THE CAT SAW THE DOG
What is the alteration here?
Substitution leading to Point Mutation
The Original was: THE CAT SAW THE DOG
What is the alteration here?
Deletion leading to Frame-Shift Mutation
The Original was: THE CAT SAW THE DOG
What is the alteration here?
Insertion leading to Frame-Shift Mutation
Mode of Inheritance?
AD
Official Description of Karyogram
Triploidy, 69 XXX
Official Description of the Karyogram
46, XY, r(4)(p16q35)
Which Abnormality and Consequence?
Ring Chromosome - Mental Retardation
What is the change in c (dna amount ) in meiosis?
A.) 2c-2c-2c-2c
B.) 2c-2c-2c-1c
C.) 2c-4c-2c-2c
D.) 2c-4c-2c-1c
E.) 2c-4c-2c
D.) 2c-4c-2c-1c
What is the change in n (chromosomes amount ) in meiosis?
A.) 2n-2n-2n-2n
B.) 1n-2n-2n-2n
C.) 2n-2n-1n-2n
D.) 2n-2n-1n-1n
E.) 1n-2n-2n-1n
D.) 2n-2n-1n-1n
What is the change in n (chromosomes amount ) in mitosis?
A.) 2n-4n-2n-2n
B.) 2n-4n-2n-2n
C.) 2n-2n-2n-2n
D.) 2n-4n-2n-1n
E.) 1n-4n-2n-2n
C.) 2n-2n-2n-2n
What is the change in c (dna amount ) in mitosis?
A.) 2c-4c-4c-1c
B.) 2c-2c-4c-2c
C.) 2c-4c-2c-2c
D.) 4c-4c-4c-2c
E.) 2c-2c-2c-1c
D.) 4c-4c-4c-2c
What is the the appropriate bands of the parents and the affected offspring in the empty frames? (Upper/Lower/Both)
Father and Mother - Both
Daugther - Upper
Give the geno- and phenotype of all the family members (1, 2, 3, 4, 5, 6).
1 - Healthy Heterozygote , 2 - Healthy Heterozygote , 3 - Healthy Homozygous Dominant, 4 - Disease, Homozygous Recessive, 5+6 - Healthy Heterozygote
Inheritance Pattern?
XD
What is the number of the VNTR test proving that C is the Child of A and B?
1
Inheritance Pattern?
AD
