Genetics - Practice Questions Flashcards by Guy Ben Arie

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

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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

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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

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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

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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

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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

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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

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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)

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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

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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

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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

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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

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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

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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

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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

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What is the sex of the subject that has this karyogram?

Female

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Is there any disorder in subject that has this karyogram?

If yes, what is it ?

Yes,

Aneuploidy, Chromosome 7 Trisomy

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Which chromosomes can be involved in that kind of mutation ? (Like in the karyogram)

Any chromosome

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Give the official description of this karyogram

47 ,XX + 7 Trisomy

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What is the sex of the subject with this Karyogram?

XX , Female

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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.

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Which chromosomes can be involved in this kind of mutation?

Centric Fusion -Occurs in Acrocentric Chromosomes:

13, 14, 15, 21, 22

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What is the official description of the presented anomaly?

45, XX (t:14, 15) (Robertsonian translocation)

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mode of inheritance

Autosomal Ressecive

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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. ## Footnote 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 : ## Footnote 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? ## Footnote 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? ## Footnote 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: ## Footnote 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

An interstitial deletion of paternal chromosome subregion 15q11-q13 results in Prader-willi syndrome (PWS). The deletion of the same subregion of maternal chromosome results in other disease - Angleman syndrome: The reason for this is: A.) Genomic imprinting B.) non-Mandelian inheritance C.) Mitochondrial inheritance D.) Nuclear inheritance E.) Variable expressivity

A.) Genomic imprinting

A genetic defect in human result in the absence of sweat glands in the skin. Some men have this defect all over their bodies, but in women it is usually expressed in a peculiar way. A women with this defect typically has small pataches of skin with sweat where glnads are lacking. This pattern suggests the phenotypic effect of: A.) Chromosome Mutation B.) Gene Mutation C.) Chromosome Inactivation D.) RNA Splicing E.) Chimerism

C.) Chromosome Inactivation

Which modes of inheritance are possible in this pedigree ?

Examples for the same Mode of Inheritance

Vit-D resistant Hypophosphatemia, Fragile-X syndrome, Amelogenesis Imprefecta

Mode of Inheritance

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)

Which of the following mutation locations can cause altered transcription? ## Footnote A.) Promotor Region B.) Exon C.) Intron D.) Polyadenylation site E.) 5' UTR

A.) Promotor Region

Which of the following mutation locations can cause stop or altered codon? ## Footnote A.) Promotor Region B.) Exon C.) Intron D.) Polyadenylation site E.) 5' UTR

B.) Exon

Which of the following mutation locations can cause altered regulation of transcription? ## Footnote A.) Promotor Region B.) Exon C.) Intron D.) Polyadenylation site E.) 5' UTR

C.) Intron

Which of the following mutation locations can cause mRNA instability? ## Footnote A.) Promotor Region B.) Exon C.) Intron D.) Polyadenylation site E.) 5' UTR

D.) Polyadenylation site

Which of the following mutation locations can cause alteration of protein synthesis? ## Footnote A.) Promotor Region B.) Exon C.) Intron D.) Polyadenylation site E.) 5' UTR

E.) 5' UTR

Mode of Inheritance

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

In Sickele cell anemia there is a change in one amino acid (Glu to Val). What is the cause of this change? ## Footnote A.) Non-sense Mutation B.) In-Frame Mutation C.) Frame-Shift Mutation D.) Deletion E.) Miss-sense Mutation

E.) Miss-sense Mutation

Put the following items in hierarchical fashion: G-Band, Codon, Exon, Nucleotide, Intron, Gene, Chromosome arm, Chromosome, Sister Chromosome

Nucleotide, Code, Exon, Intron, Gene, G-band, Chromosome arm, Sister Chromatids, Genome

Which disease is caused by this kind of mutation? THE CAT SAW THE DOG → THE HAT SAW THE DOG: A.) Duchene Muscular Dystrophy B.) Huntington Disease C.) Down Syndrome D.) Cystic Fibrosis E.) Sickel cell Anemia

E.) Sickel cell Anemia

Which disease is caused by this kind of mutation? THE CAT SAW THE DOG → THE CAT SAW SAW SAW THE DOG: A.) Becker Muscular Dystrophy B.) Huntington Disease C.) Down Syndrome D.) Cystic Fibrosis E.) Sickel cell Anemia

B.) Huntington Disease

Which disease is caused by this kind of mutation? THE CAT SAW THE DOG → THE CAT THE DOG: A.) Marfan Syndrome B.) Huntington Disease C.) Down Syndrome D.) Cystic Fibrosis E.) Sickel cell Anemia

D.) Cystic Fibrosis \*Mostly due to deltaF508 (deletion of phenylalanine at the 508 position in the protein)

Male pattern baldness is a _____ trait: A.) X-linked B.) Y-linked C.) Sex-linked D.) Sex-Influenced

D.) Sex-Influenced

NOT true for MtDNA: A.) Has many repair mechanisms B.) Rate of mutations is 10 times higher C.) Contains 2 rRNAs and 22 tRNAs D.) Has no introns D.) Variable expression in mitochondrial disease is due to heteroplasmy

A.) Has many repair mechanisms (FALSE one)

Mode of Inheritance?

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

Which type of chromosome abnormality is charcterisitc for centric fusion? ## Footnote A.) Trisomy B.) Monosomy C.) Aneuploidy D.) Polypoidy E.) Structural aberration

E.) Structural aberration

Not true for structural chromosome aberration: ## Footnote A.) Occurs in mitosis B.) Caused by abnormal crossing over C.) Results in chromosome breakages D.) One or more extra copy of chromosome in the cell E.) An example is terminal deletion

D.) One or more extra copy of chromosome in the cell (Not true)

What is true for spermatogenesis: ## Footnote A.) In the pachyten the homologous choromosomes are bound closely together by synptonemal complex B.) Meiosis is arrested at the first mieotic division C.) Meiosis (I and II) produce one sperm cell and 3 polar bodies D.) Cyclic events stimulated by hormones E.) DNA replication occurs between Meiosis I and Meiosis II

B.) Meiosis is arrested at the first mieotic division

A synptonemal complex means: ## Footnote A.) Ladder like structure, forms in pairing homoulug chromosomes B.) the internal structure of nucleoprotein that makes up a chromosome C.) Spindle like fibers that attach to homolougus chromosomes during meisosis D.) Spindle like fibers that attach without binding chromosomes

A.) Ladder like structure, forms in pairing homoulug chromosomes

Which pairing is correct? ## Footnote A.) Diploten - Complete separation of homologous chromosomes B.) Leptothene - Formation of synapsis C.) Diakinesis - chromosome alignment in the middle of the cell D.) zygothene - chaismata E.) Pachythene - crossing over

E.) Pachythene - crossing over

Humen defect that is caused by non-Disjunction? A.) Huntington Disease B.) Turner syndrome C.) Cystic Fibrosis D.) Cri-du-chat syndrome E.) Thalamsemia

B.) Turner syndrome

What method should be used to check if a child has the familial muitation leading to Huntington Disease? A.) Westren Blot B.) RT-PCR C.) VNTR based Southren Blot D.) Northern Blot E.) SNP based Southren Blot

C.) VNTR based Southren Blot

What characteristic of the genetic code allows for lower mutation likelyhood? A.) Univesal B.) Non-overlapping nature C.) Triplet based D.) Degenerative E.) More than one stop codon

D.) Degenerative

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

Mutlifactorial disease include; EXCEPT: ## Footnote A.) Autoimmune Diseases B.) Psychiatric Disease C.) Ecogenetic Diseases D.) Congenital Birth Defects E.) Hypertension

C.) Ecogenetic Diseases (For example PKU)

Which type of inheritance results in continouse variation - often a bell shaped curve - because genes at many loci are involved? ## Footnote A.) Mutlifactorial B.) AD C.) Sex-Limited D.) X-Linked E.) Sex-Influenced

A.) Mutlifactorial

Why are AAVs promising delivery systems for in vivo genome editing applications? ## Footnote A.) They have a large packging capacity B.) Only one AAV is enough for a dimeric TALEN pair C.) They have high delivary efficacy for several tissue types D.) AAV-mediated nuclease expression is often constitutive

C.) They have high delivary efficacy for several tissue types

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

Chiasm, where? a. lepthothen. b. zygothen. c. pachithen. d. diplothen. e. Diakinesin.

d. diplothen.

Inheritance Pattern?

What is the number of the VNTR test proving that C is the Child of A and B?

Inheritance Pattern?