The term mutation refers to:
a heritable change in the DNA of a cell
A heritable change in DNA base sequence is called a:
mutation
Replacing a thymine nucleotide with a guanine is an example of a:
transversion
Replacing an adenine nucleotide with a guanine is an example of a:
transition
Assume that a wild-type sequence is 5'AGCCTAC3'. Indicate the sequence that might be produced by a transversion
5'ATCCTAC3'
A mutation in which parts of two nonhomologous chromosomes change places is called a:
translocation
Indicate the statement that is most accurate regarding mutations
Mutations altering a region that does not code for a protein may alter phenotype
Assume that the mutation rate for a given gene is 5�10-6
mutations per gene per generation. For that gene how many mutations would be expected if 10 million sperm are examined?
50
Which type of mutation is least likely to revert?
deletion
Consider the following results. When 50 million sperm were examined for a specific mutation, 100 mutations were found. Indicate the mutation rate for that gene.
2�10-6
Assume that a researcher set out to duplicate the Luria-Delbruck fluctuation experiment.This researcher planted twenty small flasks with bacteria from the same colony and let them grow overnight. The next morning the researcher noticed that all but one of
Not like the Luria-Delbruck results, namely identical numbers of resistant colonies
The results of the Luria-Delbruck fluctuation experiment indicated that:
bacteria become resistant to phage by random spontaneous mutation
In the Luria-Delbruck fluctuation experiment, the bacteria + phage plates showed:
some plates had no resistant colonies, a few plates had very many resistant colonies
The hydrolysis of a purine base from the deoxyribose-phosphate backbone is called:
depurination
Assume that in the organism under study the DNA polymerase has an error rate of 1 mistake in every 106 bases copied. However, the overall mutation rate is much lower.This is most likely because:
repair mechanisms correct errors made by the polymerase
Excision repair corrects DNA by:
detecting, removing, and replacing a single stranded fragment of damaged DNA
Thymine dimers are caused by
UV light
UV light is a mutagen that can cause
thymine dimers
The genetic condition xeroderma pigmentosum, which can lead to skin cancer, results from
inability to correct UV induced dimers
The bacterial repair system that corrects mismatched bases after polymerization is able to discriminate between the old and newly made DNA strands because:
older DNA contains methyl groups at specific sequences
The consequence to a bacterial cell of a mutation that inactivated the enzyme thatmethylates the A of the sequence GATC in newly made DNA would be
failure to distinguish old and new DNA during mismatch repair
Unequal crossing over results in
a creation of deletions and duplications
The heritable disorder fragile X syndrome, a major cause of mental retardation, is caused by:
duplication of multiple three-nucleotide repeats.
If a man shows the premutation allele for fragile X syndrome, what is the probability that he will pass it on to his son?
0%
The duplication of the triplet sequence CGG resulting in elongation or breakage of the X chromosome is termed:
fragile X syndrome
Genes on the X chromosome of mammals and Drosophila are particularly suitable for genetic study because
males have only one X and most genes behave as haploids
If a base analog such as 5-Bromouracil is used as a mutagen, how many generations will be required to mutate the codon for proline (CCC) into the codon for alanine (GCC)?
it will not occur
Base analogs differ from other classes of mutagen in that they:
only work during DNA replication or repair
Intercalating agents such as acridine orange function as mutagens to:
fit between stacked bases and disrupt replication.
Alkylating agents such as ethylmethane sulfate (EMS) function as mutagens to:
add ethyl or methyl groups
In the Ames test for mutagenicity:
auxotrophic bacteria are converted to prototrophs which survive
In the Ames test for mutagenicity, rat liver enzymes are included with the compoundunder test because:
rat liver enzymes may modify or break down some compounds
Assume that a new low-calorie sweetener is developed. The structure is novel and is tested with the Ames test for mutagenicity. The following results are obtained:
Sample Number of his+ revertent colonies
distilled water 2
distilled water + rat liver enzy
The sweetener is not mutagenic but can be converted into strong mutagens
The Ames test for mutagenicity is useful to identify potential carcinogens because:
mutagens that affect bacterial DNA are likely to cause human mutation
The size of the human genome in base-pairs is about:
2.75X10^9
A complementation group is:
a group of mutations that are in the same gene and do not complement each other.
Choose the statement that is most correct regarding the rII-strain of T4 that Benzer studied.
Produces larger plaques, grows in E. coli B, not in E. coli K(?).
A plaque is:
an area on a plate containing phage and dead or destroyed bacteria
Shown below are the results of a series of coinfections using T4 rII- strains similar tothose employed by Benzer. Each strain contains a different deletion mutation. Ability to produce wild-type progeny phage is indicated by (+), (o) indicates no wild-typ
CADBE
Shown below are the results of a series of coinfections using T4 rII- strains similar tothose employed by Benzer. Each strain contains a different deletion mutation. Ability to produce wild-type progeny phage is indicated by (+), (o) indicates no wild-typ
BADCE
Choose the statement that best distinguishes a complementation test and arecombination analysis when examining mutations in phage
A)Both tests require two different mutations.
B) Recombination can only occur between two genes.
C) Complementation results c
C
Shown below are the deletion maps of a series of rII- mutations. The deleted region isindicated as (......) and the intact region as ______.
1 _____(..........)____________________
2 _________________(..........)________
3 (.........)_____________________
ABDEC
Shown below are the deletion maps of a series of rII- mutations. The deleted region isindicated as (......) and the intact region as ______.
1 ___________(...........)_______________
2 _________________(...........)_________
3 (.....................)_____
DEBAC
Shown below are the deletion maps of a series of rII-
mutations. The deleted region isindicated as (......) and the intact region as ______. Note that strain 5 carries twodifferent deletions.
1 ___________(...........)_______________
2 _________________(.
CADBE
Indicate the correct order for one round of infection by bacteriophage T4.
1. Lysis of host cell.
2. Phage proteins and DNA synthesized, host DNA degraded.
3. Assembly of phage within host cell.
4. Phage body enters host cell.
5. Phage injects DNA into ho
5, 2, 3, 1
How many progeny phage are released when a single E. coli cell is lysed by phage T4?
between 100 and 1,000
Indicate which of the following is least important in doing a complementation test with coinfection of phage T4.
Counting the plaques that are produced on E. coli K(?).
Assume that a researcher is studying coat color in voles. Three strains of white volehave been isolated: milky, blanc, and weiss. White is a recessive trait in each strain.Homozygous white voles are obtained for each strain. Consider the following crosses
milky and blanc have mutations on the same gene, weiss has a mutation in a different gene
Assume a researcher is studying the rII locus of phage T4. Three rII-strains areobtained: A, B, and C. When coinfections are performed in E. coli strain K(?) the following results are obtained:
A�B = plaques form
A�C = plaques form
B�C = no plaques form
T
B and C carry mutations in the same gene, A is on a different gene
Assume a researcher is studying the rII locus of phage T4. Four rII-strains are obtained:A, B, C and D. When coinfections are performed in E. coli strain K(?) the following results are obtained:
A�B = lysis
A�C = lysis
B�C = no lysis
B�D = no lysis
C�D =
A carries a mutation in one gene, B, C and D are on a different gene, B and D both carrythe same mutation
Choose the statement that is most accurate concerning biochemical pathways.
A) All enzymes in the pathway catalyze the same reaction.
B) If an enzyme in a pathway is inactive, adding excessive amounts of its substrate willrestore the normal phenotype.
C)
C
n the human genetic disorder alkaptonuria, urine turns black because of the presence of homogentisic acid in individuals with the trait. This is due to:
failure of individuals with alkaptonuria to manufacture enzymes involved in the breakdown of homogentisic acid
ndicate the false statement regarding amino acids.
A) Every amino acid contains a carboxyl group.
B) The side chain or R group differs for each amino acid.
C) Amino acids are joined together by peptide bonds.
D) The end of the polypeptide termed the N ter
E
Indicate the false statement regarding amino acids.
A) Several amino acids linked together are termed an oligopeptide.
B) Amino acids are linked by peptide bonds that join two amino groups together.
C) The C terminus of a polypeptide chain contains a free
B
Choose the condition below that does not involve a defect in an enzyme pathway
sickle cell anemia
Choose the interaction listed below that is not involved in maintaining tertiary structurein protein molecules
A)covalent bond
B) hydrogen bond
C) hydrophobic/hydrophilic interactions
D) ionic interactions
E) all of the above may be involved in maintainin
E
The condition sickle-cell anemia is due to
substitution of animo acid
Choose the statement below that is not true regarding sickle-cell anemia.
A) Individuals who are heterozygous for the sickle cell allele can not make hemoglobin.
B) The sickle-cell hemoglobin molecule contains an amino acid substitution.
C) The hemoglobin
A
Though sickle-cell anemia is frequently lethal for individuals who are homozygous for the sickle cell allele, natural selection seems to have maintained that allele in certain geographic locations. A likely explanation for this observation is:
individuals who are heterozygous for the sickle-cell allele are protected from malaria.
The structure of a polypeptide that is characterized by a three dimensional shape with acharacteristic geometry at local regions maintained by hydrogen bonds is
secondary structure
The structure of a protein that involves the interaction between two distinct polypeptidechains is
secondary structure
Assume that a certain strain of bacteria carries a mutation that causes it to die at hightemperature (37�C), but grows normally at cooler temperatures. This mutation is termed
Conditional lethal that dies under restrictive conditions
Mutations that abolish the function encoded by the wild-type allele are known as
null mutations
A neomorphic mutation results in an allele that
produces novel proteins or cause inappropriate expression resulting in a new phenotype
Assume that a transition mutation results in an amino acid substitution in the resulting polypeptide. What level of protein structure might be affected as a result?
all levels might be affected by a single amino acid substitution
The photoreceptor protein rhodopsin:
is found in rod cells and is sensitive to weak light at many wavelengths
Examination of the rhodopsin gene family provides evidence for gene evolution by:
duplication and divergence.
Red-green color blindness is more common in males than females because:
both the red and the green pigment genes are on the X chromosome
Consider the gene for color in a particular flower. Three alleles exist: dark blue, white,and sky. Flowers homozygous for each allele produce the characteristic color. In heterozygotes, incomplete dominance occurs and intermediate colors are seen in a nat
6
The appearance of a novel phenotype resulting from the substitution of a single base pair might be due to:
A change in the amino acid sequence only, change in the amount of protein expressed, alteration in a gene that codes for a nontranslated RNA, and change in the developmental time or location at which a gene is expressed
The term fecundity refers to:
ability to produce offspring
Assume that for a given gene a mutation creates an allele that functions as a dominant negative. The gene codes for a protein that forms a trimer within the cell. If at least one of the subunits has the mutant structure the entire protein is inactivated.
12.5%
A neomorphic dominant mutation in the
Antennapedia( Antp) gene of Drosophila causes
growth of leg from the head region
In the usual flow of genetic information (often called the Central Dogma), which of the following best represents the expression of genes?
DNA - RNA - Protein
The cellular organelle responsible for protein synthesis is the:
ribosome
The scientists credited with postulating the basis for the Genetic Code are
Watson and Crick
A codon is:
a three base sequence of mRNA that codes for an amino acid
Which of these is NOT a character of the genetic code?
A) There are the same number of codons as there are amino acids.
B) The code is used by nearly every living organism.
C) Some amino acids have multiple codons.
D) The code is degenerate.
A
Charles Yanofsky helped decipher the genetic code working with the _____ biosynthesis genes in _______.
tryptophan; Escherichia coli
A sequence of DNA that reads: 5' ATGCCTGAATCAGCTTTA 3' should code for ____ amino acids after all steps of conversion into protein are complete.
6
How many DIFFERENT amino acids could be coded for using the synthetic mRNAsequence of (5' UGCUGCUGC 3')?
3
There are ______________ usually found in the genetic code
1 start codon and 3 stop codons
The pattern or sequence in which a molecule of mRNA is deciphered by a ribosome is called the:
reading frame
Which of these terms is NOT used as a nickname for a stop codon?
emerald
Nonsense codons are
codons that code for no amino acids
Which of these is NOT a step in transcription?
A) replication
B) initiation
C) termination
D) elongation
A) Replication
Splicing of transcripts normally occurs only in:
only eukaryotes
The sequences within mRNA that are spliced out (removed) are called:
introns
The (expressed) sequences within mRNA that code for gene products are called:
exons
The retroviruses, including HIV, are unique because they do:
reverse transcription
A typical example of a genetic system that employs RNA splicing is:
the genes responsible for making antibodies in humans
Experiments that are done outside a living cell are describe by the Latin term:
in vitro
Experiments that are done inside a living cell are describe by the Latin term
in vivo
The enzyme that makes RNA from a DNA template is:
DNA-dependent RNA polymerase
Transcription occurs in the ________ and translation occurs in the __________ of EUKARYOTIC cells.
nucleus; cytoplasm
Transcription occurs in the ________ and translation occurs in the __________ of PROKARYOTIC cells.
cytoplasm; cytoplasm
Which of the following statements is true under ordinary conditions?
A) DNA and RNA last only for a short time within a cell.
B) DNA lasts forever within a cell while RNA only lasts a short time.
C) RNA lasts forever within a cell while DNA only lasts a s
B
In the modification of eukaryotic mRNA, a "cap" consisting of a/an _________ and atail consisting of _______ are usually added to the transcript
methyl group; multiple adenines
RNA polymerase binds to a sequence called a/an ______________ before beginning transcription.
promoter
Ribosomes are composed of:
rRNA and protein
A tRNA molecule looks like a compact ____ when it is folded into its functional configuration
L
Aminoacyl-tRNA Synthetase is the enzyme that:
adds the appropriate amino acid to an uncharged tRNA
Which enzyme forms peptide bonds between adjacent amino acids during polypeptidesynthesis?
peptidyl transferase
A bacterial (prokaryotic) ribosome is composed of ______ subunits.
30S & 50S
An anticodon is a physical component of a/an _______ molecule
tRNA
Which of these processes are coupled (linked) in prokaryotes but NOT in eukaryotes?
A) transcription and translation
B) replication and transcription
C) replication and translation
D) replication, transcription, and translation are not separate in prokary
A
A mutation that is characterized by a change in the DNA sequence, but no change in theresulting protein sequence, is called a
silent mutation
A mutation that changes a codon sequence, and subsequently changes the amino acidthat should have been placed at that point in the polypeptide chain, is called a:
missense mutation
A mutation that changes a codon that originally coded for an amino acid into a stopcodon is called a
nonsense mutation
A mutation that occurs when a base is inserted into or deleted from a DNA sequence,completely altering an entire amino acid sequence, is called a:
frameshift mutation
Drugs like AZT, ddC, or ddI work against the AIDS virus because they:
look like nitrogenous bases and block viral reverse transcriptase
A tRNA that recognizes a nonsense codon, and inserts an amino acid where proteinsynthesis should have stopped, is called a
suppressor tRNA
Protein synthesis begins with the amino acid ___________, as its codon is the one usedas the "start codon" by nearly all organisms
methionine
The technique of primer walking begins with a vector-based primer. This is used to obtain DNA sequence for one end of a long insert. The partial sequence of the insert is used to:
design a new primer that will sequence into the next unknown section of the insert
What is the reason for partial digestion of genomic DNA with restriction enzymes?
Producing fragments that are slightly longer than a complete digest would produce
Which of the following is an example of a recombinant DNA molecule?
A genomic fragment of human DNA ligated to a bacterial plasmid vector
One of the reasons that PCR is useful in diagnosis of HIV is because it
detects an infection at an earlier stage than the current standard test
PCR cannot be successfully performed without
at least some sequence information about the region to be amplified.
What information CANNOT be determined from the DNA sequence of a cDNA clone?
sequence of the promoter
In Sanger (enzymatic extension) sequencing, what causes DNA synthesis to terminate ata specific base?
Nucleotide triphosphates that lack a hydroxyl
What technique is used to separate DNA molecules that are the size of whole chromosomes?
pulsed field gel electrophoresis
In gel electrophoresis of DNA, fragments move at different rates because they have different:
sizes
The recognition sites for the restriction enzymes BamHI, XbaI and BglII areG^GATCC, T^CTAGA and A^GATCT, respectively. Which enzymes leave compatibleends that can be ligated together?
Only BamHI and BglII fragments are compatible.
A genomic library is made for an organism with a haploid genome of 5�10^7 bp. If thefragments are approximately 20 kb each, how many clones would be screened to ensurea 95% probability of a particular locus being represented at least once?
1.25x10^4
What charge does DNA have, and what gives it this charge?
negative, from the phosphates
T4 phage DNA polymerase has 2 activities. One is polymerization. The other is 3' to 5'exonuclease activity against 3' overhangs, which are sticky ends that have a single-stranded region at the 3' end of one of the strands. The enzyme converts sticky ends
The exonuclease activity will blunt both the PvuI and SacII ends.
An EcoRV (GAT^ATC) fragment that contains a promoter, is ligated to a SmaI(CCC^GGG) fragment that contains most of a protein-coding gene. What is the probability that the newly introduced ATG will be in frame with the protein encoded inthe SmaI fragment?
1 in 3
In a human genomic DNA library made by complete SalI (G^TCGAC) digestion,approximately how many clones constitute a genomic equivalent?
700,000
PCR is used to:
amplify minute quantities of a DNA fragment
Restriction enzymes were named because they restrict:
the capacity for viral growth
Which of the following would not have its gene represented in a cDNA library from red blood cell precursors?
an rRNA
DNA molecules are separated by pulsed field gel electrophoresis when they are
too long to be separated by standard agarose gels.
If DNA had 5 different bases, a restriction enzyme with a 4-base recognition sequencewould cut DNA approximately every:
625 bp
If DNA had 5 different bases, approximately how many fragments would result fromcutting a 1 Mb piece of DNA with a 4-base cutter?
It is shorter
Which of the following would be found in a cDNA library, but not a genomic library?
exons
A genomic library is a:
collection of DNA fragments from an organism, inserted into vectors
The lacZ gene is sometimes included in a cloning vector. What does it encode?
A detectable enzyme that is not produced if the gene is interrupted by an insert
A plasmid has tetr and lacZ genes for tetracycline resistance and �-galactosidase,respectively. There is a single EcoRI site within lacZ, and a single Hind III site withintetr . The EcoRI-HindIII cut plasmid is combined with a DNA fragment with compatible
tetracycline sensitive and white if grown on X-gal
Genomic DNA is isolated from bacteria. After a long digestion with a 6-base cuttingenzyme that recognizes the sequence GAATTC, the DNA is not cut. The genome is 4Mb, so there should be approximately 1,000 sites in the DNA. What is the most likelyexplanati
The bacterium methylated the DNA, because it produces the 6-base cutting enzyme
A 6-base cutting enzyme should cut every 4kb, on average. Approximately how manysites are in the human genome (for simplicity, use 4 million kb as the size of the humangenome)?
1,000,000
The basic problem in isolating/cloning a human gene is that the genome contains __________ of base pairs, and a gene is usually several __________ base pairs inlength
billions, thousand
What is the function of the ampr gene in a vector?
It is a selectable marker
A circular DNA of 1 kb length is cut with a restriction enzyme whose preciserecognition sequence is not known. The digest yields 4 fragments of approximatelyequal size. What is the most likely conclusion from these data?
The enzyme is a 4-base cutter
Which choice is NOT a characteristic of a plasmid used as a cloning vector?
A) Confers a detectable property on a host cell.
B) Can be purified away from the host cell's genome.
C) Replicates independently.
D) Replicates itself and the inserted DNA.
E) Me
E
Where do restriction enzymes come from, and what is their normal physiologicalfunction?
Bacteria produce them to protect against viral invasion
How do bacteria protect their own DNA from the restriction enzymes they produce?
Digestion is blocked by -CH3 groups added to recognition sequences in their DNA
If the restriction enyzme EcoRI cuts a linear 19 kb piece of DNA into fragments of 1, 3,6 and 9 kb, what size fragment (in kb), would NOT be possible from a partial digest?
5
A restriction enzyme with a recognition site of 10 bp cuts an average of every
4^10 bp
A restriction enzyme with a recognition site of CCNNGG (where N is any base) cuts anaverage of every:
250bp
Reverse transcriptase is an enzyme made by
retroviruses
Which vector is appropriate for cloning an insert of 1 Mb?
YAC
A 16 kb linear DNA is cut with EcoRI and BamHI. The EcoRI digest yields fragmentsof 2, 6 and 8 kb. The BamHI digest yields fragments of 5 and 11 kb. An EcoRI-BamHIdouble digest yields 2, 3, 5 and 6 kb fragments. The map of this DNA has:
2 EcoRI sites and 1 BamHI site
A 16 kb linear DNA is cut with EcoRI and BamHI. The EcoRI digest yields fragmentsof 2, 6 and 8 kb. The BamHI digest yields fragments of 5 and 11 kb. An EcoRI-BamHIdouble digest yields 2, 3, 5 and 6 kb fragments. If the 3 kb fragment from the doubledigest
8 kb
A 10 kb linear DNA is cut with EcoRI and HindIII. The EcoRI digest yields fragmentsof 2 and 8 kb. The HindIII digest yields fragments of 3 and 7 kb. What are the possiblefragments (in kb) from an EcoRI-HindIII double digest?
1, 2, 7 or 2, 3, 5
When bacterial transformants containing a library are transferred to nitrocellulose filtersand screened, one of the steps is treatment with an alkaline solution. What does this do?
Lyses the cells and denatures the released DNA
In references to the "-globin locus" or "�-globin locus", the term "locus" me
a chromosome region with a cluster of related globin protein genes
How are the genes in the �-globin locus different from each other?
They are expressed at different times in development
Pseudogenes are evidence for
gene duplications
Which statements are true?
1. In thalassemias, globin proteins are produced, but contain a point mutation.
2. In sickle cell anemia, globin proteins are produced, but contain a point mutation.
3. Sickle cell anemia is caused by a mutation in the �-globin
2 and 3
In cosmids, what is the function of the cos sites?
allow packaging into viral shells
If a single DNA molecule is amplified by PCR, how many DNA molecules will there beafter 6 cycles?
64
Which mutation in the �-globin gene could, in theory, be detected with a genomic clone but not with a cDNA clone?
A promoter mutation that prevents transcription
Which technique is required to generate a restriction map?
electrophoresis
An organism's genome is:
the DNA content and sequence of all of an organisms genes.
The human genome contains approximately how many microsatellites?
one hundred thousand
Which is not true of DNA arrays?
A) Thousands of DNA fragments of known sequence are attached to microchip.
B) The attached fragments may contain allelic variants.
C) Fragments from a test single stranded DNA sample may hybridize to DNA on the chip.
D) In
E
Genomics is:
the branch of biology that develops and applies mapping, sequencing and computational tools
STSs are:
A) microsatellite sequences.
B) generally highly polymorphic.
C) unique markers along the chromosome.
D) a and b
E) b and c
E
Over six thousand STSs markers have been placed on the human map and they are on average about 0.5�10^3
kbp apart. If 30,000 markers were available, what would be the average distance between markers?
100 kb
FISH analysis is useful for:
determining the chromosomal location of a gene
A contig is
sets of two or more partially overlapping cloned DNA fragments
Sequence conservation among mammals allow researchers to
screen YACs made from human DNA for coding regions by hybridization to mouse DNA.
Model organisms:
A) allow the discovery of similar pathways
B) allow the discovery of genes that are conserved across evolutionary time.
C) allow the discovery of every human gene.
D) a, b, and c
E) a and b
E
Below are several steps involved in FISH. From the choices available, pick the order of steps that would be successful.
1. Fix chromosomes and denature the DNA.
2. Arrest cells in metaphase.
3. Take a picture using ultraviolet light.
4. Drop cells onto mi
Order 2, 4, 1, 5, 6, 3
Karyotypic analysis is:
used for locating cloned genes on particular parts of a chromosome.
The study of polypeptide motifs allows researchers:
to discern possible biochemical properties of a protein.
Homology is:
between two protein sequences suggests that the genes encoding them derive from asingle ancestral gene, can be 90%, and is indicated by similarity in the coding region
What DNA sequence information is not present in a cDNA?
A) the promoter
B) the introns
C) the exons
D) the 3' untranslated region
E) a and b
E
If you find a helix-loop-helix motif, what function might you postulate for this polypeptide?
nuclear polypeptide
If you find a zinc-finger motif, what function might you postulate for this polypeptide?
transcription factor
Gene therapy is possible for some genes in humans at present. Which of the followingare potential problems?
A) large size of genes
B) identifying the responsible gene
C) random integration of transforming DNA
D) tissue-specific gene expression
E) all of t
F
The location of a gene on the Y chromosome could be identified by:
A) Northern analysis
B) FISH
C) genomic Southern analysis
D) a and b
E) b and c
E
Chromosome walking:
will allow one to move from one clone to another
If you wanted to study a cell cycle control gene, which model organism would be best suited?
S. cerevisiae
If you wanted to study a gene involved in apotosis, which model organism would be best suited?
C. elegans
If you wanted to study a gene involved in rod cells in the retina, which model organismwould be best suited?
M. musculus
Stem cells are useful targets for gene therapy because:
they are dividing and able to differentiate
The Human Genome Project has six distinct objectives. Which of the following is NOTone
to generate capital for the United States government
The most common method for genotyping allelic SSRs is by
PCR and gel electrophoresis
A method of using the ends of unconnected contigs as probes to further map a genomeis called:
chromosomal walking
A method of analysis that uses a pattern of restriction fragments sizes to compareregions of gemomic DNA
DNA fingerprinting
Mapping strategies often utilize the PCR of unique sites in the genome which are polymorphic and whose sequence is known. These sequences are best called
SSCP
The highest resolution map of a genome can best be generated from:
sequence analysis
Random generation of overlapping insert fragments from large clones for the purpose of sequence analysis is termed:
shotgun
Which of the following are dissimilar between mouse and man:
karyotype
There are estimated to be how many genes in the human genome:
40,000-60,000
Genome sequencing projects have and will continue to:
expedite gene-finding and gene-function analyses, enhance studies on evolution, and increase the number of known genetic polymorphisms
Noncoding RNAs include:
tRNAs, rRNAs, snoRNAs, and snRNA
Genes encode:
proteins and non coding RNAs
Protein analysis has shown that humans and worms have approximately how much proteome homology:
43%
Repeat sequences constitute how much of the human genome:
50%
Which of the following is not one of the five classes of repeat sequences:
A) segmental duplications
B) pseudogenes
C) DNA coding for 5' UTRs
D) transposon sequences
C
Transposon-derived repeats constitute how much of the human's genome:
45%
A gene considered to generate the upper limit of known splice variants might have how many:
500-1000
Which of the following is not one of the four classes of transposon-derived repeatsequences:
A) LINES
B) SINES
C) DNA transposons
D) Long terminal repeat transposons
E) pseudogenes
E
Which of the following is not considered a distinct type of organization within agenome:
A) presence of gene families
B) junk DNA
C) gene-rich regions
D) gene deserts
B
Which of the following is not true:
A) human race differences are distinguishable by genotype and phenotype.
B) the human population encompasses a number of different races.
C) sequence analysis has found that there is more genotypic variation within a ra
A
Which of the following is not a method for measuring mRNA levels
:A) DNA microarray
B) sequence analysis
C) oligonucleotides array
D) Northern analysis
B
The population of mRNA expressed in a single cell or cell type is called:
transcriptome
Deleterious mutations in which of the following genes leads to a 70% predispositiontoward breast cancer
BRCA1
A mass spectrometer is used to:
following ionization and transfer to a vacuum, a molecule's mass can be determined bymigration in an electric field
Which of the following is a technique used to quantitatively define a transcriptomeincluding very rare transcripts:
MPSS
If the parents are Cfcf , the chance that any future child will beCfcf is
1/2
If a PCR amplified sample hybridizes with two allele specific probes, one normal andone mutant sequence, a carrier is identified if:
both samples give a signal
Molecular geneticists equate an allele with
any DNA site that is different among genomes
When the 250 kb region that encompass the Cf gene is sequenced in two CfCf individuals, it is found that on the average the following number of base sequences isdifferent between them.
700
For a gene or a locus to be considered polymorphic it must satisfy the following twoconditions
must be present in two or more sequence variations in at least 1% of the population
When two haploid genomes are compared, about how many base sequence differences can be found in the non-coding DNA?
3.4 million
Which is the most frequent cause of DNA polymorphism?
single base differences
In microsatellites, one, two or three base sequences are tandemly repeated about:
15-100 times
The human genome contains approximately how many microsatellites?
one hundred thousand
Which of the following is the main source of variation in microsatellites?
faulty DNA replication
Microsatellites compared to coding genes show:
more variation
Deletions, duplications and insertions have the following number of bases.
from one to megabase
Deletions, and duplications are most often caused by
ionizing radiation and unequal crossing over
Restriction sites provide substrates for:
DNA endonucleases and enzymes that cut double stranded DNA
Three sequential restriction sites will produce how many fragments?
2
If the middle of three sequential restriction sites undergoes mutation, how many fragments will be expected?
1
Allele-specific probes are:
dependent on PCR and should be 20 or less bases long.
Lack of strong hybridization by an allele specific probe of about 20 bases to DNA to betested detects
the probe is too long
The strength of holding of a probe and the DNA to be tested together depends on:
length of the probe, temperature chosen during hybridization, and ionic strength of post-hybridization washes
With the microsatellite analysis feature, all of the following apply except:
A) must know the sequence of flanking markers.
B) must know the sequence of the repeat units in the microsatellite.
C) polymorhism is a matter of DNA size.
D) electrophoresis.
E)
B
Huntington disease is caused by
42 or more CAG repeats.
Positional cloning requires:
knowledge about the map location of a gene
Below are several steps involved in positional cloning. From the choices available, pick the order of steps that would be successful.
1. Examining Northerns for candidate genes in specific tissues.
2. Obtaining DNA or cells from members of a family with a
Order 3, 2, 1, 4, 5
Phenocopies of genetic diseases can arise:
from environmental stimuli in utero
Quantitative traits can be distinguished by:
being measurable and being influenced by multiple genes
Incomplete penetrance
can vary from trait to trait and is observed when the mutant genotype does not result in a mutant phenotype
If the chance a person being polymorphic for a particular microsatellite is 50%, what isthe chance that a person is polymorphic for four unlinked microsatellite loci?
6.25%
SNP is the acronym for
single nucleotide polymorphism
Below are several steps involved in Northern blots. From the choices available, pick theorder of steps that would be successful.
1. Blot the RNA from the gel to a filter.
2. Purify the RNA.
3. Separate the RNA by size in an electrical field in an agarose
Order 2, 3, 1, 4, 6, 5
Predisposition to breast cancer results from mutations:
in multiple genes and in BRCA1 that show 50% penetrance
Identification of candidate genes:
can use a possible tissue specificity of expression and can use evolutionary conservation of coding sequences.
A transgene:
can be used to create new mutant organisms, is a piece of foreign DNA that is inserted into the genome of an organism, and can be used to determine if a candidate gene is responsible for a disease phenotype
The sequence of DNA is useful for:
finding differences between individuals, finding information about protein function, finding protein motift, and duplicated genes.
To find a gene that is responsible for a mutant or disease phenotype, the researcher will
use Northern blots to find tissue-specific gene expression, pick out regions of conserved sequence by hybridization, and look for mutation
Mapping a disease gene requires:
large families with DNA and pedigrees, and large numbers of mapped physical markers with complete genomic coverage and smallfamilies with DNA and pedigrees
If a human disease gene is within 5 cM of a physical marker, then it is approximately within:
5,000 kb
If a gene is thought to be a possible disease gene, one can:
sequence alleles from affected and unaffected family members, examine the expression pattern of the gene, and make a transgenic mouse, if an appropriate mouse mutation is known
Thalidomide was a common treatment for morning sickness in the 1950s. Children bornto mothers given this drug showed the phenotypes of a genetic disease known as phocomelia, which involves shortened limbs. This may represent:
phenocopy