Genetics Question Bank

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Suppose a region of DNA is 100 bp long. How many unique sequences could it potentially represent?

4^100

The polarity of DNA synthesis is

5' to 3'

The measured distance between genes D and E in a two-point testcross is 50 map units. Where are genes D and E in relation to each other?

D and E are on the same chromosome, exactly 50 map units apart. D and E are on the same chromosome, less than 50 map units apart

How are the structures of DNA and proteins similar?

DNA and proteins are polymers composed of strings of individual subunits.

A protein with a zinc-finger domain most likely has what type of activity?

DNA binding

The ends of DNA molecules can be joined together by

DNA ligase

A BLAST search can be used for which of these applications?

to compare a nucleotide or amino acid sequence to databases from a variety of species

According to the wobble rules, a 5′ G in an anticodon can pair with U or C in a codon. Select all codons that a tRNA with anticodon sequence 3′ GCG 5′ could recognize.

5′ CGC 3′ 5′ CGU 3′

One strand of DNA has the sequence 5′ GGTCTA 3′. What is the sequence of the other strand?

5′ TAGACC 3′

Brachydactyly is a condition caused by an allele dominant to wild-type in humans, in which the fingers and toes are shortened. In a population of 10,000 people, 1,600 are BB, 4,800 are Bb, and 3,600 are bb. What percentage of people in this population have short fingers and toes?

64%

What percentage of people in this population have short fingers and toes? (required info: Brachydactyly is a condition caused by an allele dominant to wild-type in humans, in which the fingers and toes are shortened. In a population of 10,000 people, 1,600 are BB, 4,800 are Bb, and 3,600 are bb)

64%

How can a mutation in a tumor suppressor behave as a recessive allele at the cellular level but appear as a dominant allele in pedigree analysis?

At the cellular level both alleles need to be mutated for an en effect while in a pedigree the cancer may be vertically inherited.

Changes that prevent bacterial growth and reproduction on minimal medium.

Auxotrophic mutations

Using the CRISPR/Cas9 system, a genetically-engineered sgRNA complementary to a target site in the genome binds to Cas9 endonuclease. A mutation can occur at this site when

Cas9 cleaves the DNA and nonhomologous end-joining results in a small deletion.

Select all the statements that describe potential approaches to combatting antibiotic resistance.

Decreasing antibiotic use will decrease the selection pressure for resistance. Targeting bacterial cell-cell communication through quorum sensing may be a target of new antibiotics. Modified antibiotics that degrade over time would decrease selection for resistant bacteria.

G1 to 2 checkpoint

Delays DNA replication if damage to DNA has occurred

What is the relationship between methylation and genomic imprinting?

Differential methylation of DNA in males and females results in only one of the parental alleles being transcriptionally active in the offspring.

The retinoblastoma (Rb) protein regulates progression into S phase by regulating ___________ activity.

E2F

What is the purpose of the P element in the creation of transgenic Drosophila?

Efficiently transfer DNA into Drosophila chromosomes.

A scientist wants to determine whether a mutant phenotype is due to the loss of gene C or gene D, which are both deleted in a mutant fly with abnormal eyes. Mutant flies with transgenic gene C have wild-type eyes, whereas mutant flies with transgenic gene D have abnormal eyes. What can be concluded from these results?

Gene C is required for normal eye development

Which of the following is least likely to occur from the inactivation of p53?

Increased propensity to arrest in G1

What is a property of a pathogenic bacterium?

It may produce a protein that interferes with basic cellular functions.

Which of the following is correct regarding sigma factor?

It recognizes the promoter region.

If this mRNA is transcribed and translated in the mitochondria, what amino acid sequence is encoded? (photo in hw)

Met Asn Gly Trp

Changes that prevent bacterial cells from breaking down complex chemicals in the environment

Metabolic mutations

Mutations in gene with crucial protein products; often studied only as conditional lethals

Mutations in essential genes

The most common mutant allele of the PAH gene, which is responsible for the metabolic disorder PKU, has a SNP in the splice donor site of one intron. What is the simplest way to detect this allele?

PCR using two primers, one on either side of the SNP, followed by sequencing the PCR products

Phage DNA that has integrated into the viral genome.

Prophage

In the Ames test, why were rat livers enzymes included with the compound being tested?

Rat liver enzymes mimic metabolic processes which may produce a mutagen from a harmless compound.

Steps in oocyte nuclear transplantation

Remove the nucleus form the affected mother's egg. Remove the nucleus from a healthy donor egg. Insert the nucleus from the affected mother's egg into the enucleated donor egg. Fertilize the cybrid with sperm from the father. The zygote has nuclear DNA from the affected mother and the father and mitochondrial DNA from the donor.

In a test tube, a particular DNA polymerase has an error rate of 1 mistake in every 106 bases copied. Why is the mutation rate in a cell that uses this DNA polymerase much lower?

Repair mechanisms correct errors made by the polymerase.

Mutations that allow a bacterium to grow in the presence of a bactericidal agent, such as a bacteriophage or antibiotic.

Resistance mutations

Luria and Delbruck grew many liquid cultures of bacteria then spread a small sample of each culture on nutrient agar infused with bacteriophage in separate petri plates. They assayed the number of bacterial colonies that formed on each plate. What did the results of the Luria Delbruck fluctuation experiment indicate?

Resistance to phage in bacteria is caused by random spontaneous mutation.

What is one difference between using restriction endonucleases and mechanical shearing of DNA?

Restriction endonucleases cut DNA at known specific sites while shearing occurs at random sites.

Which of the following is one of the assumptions of the Hardy-Weinberg law?

The ability of all genotypes to survive and reproduce is the same

Which of the following is one of the assumptions of the Hardy-Weinberg law?

The ability of all genotypes to survive and reproduce is the same.

Select all statements that correctly describe posttranscriptional gene regulation.

The activity of CRP is regulated posttranscriptionally; CRP changes conformation when bound to an effector. An antisense RNA reduces transcription of an E. coli mRNA that encodes the toxic protein SymE. A stem-loop structure that blocks access to a ribosome binding site is disrupted at high temperatures, allowing translation to occur.

When performing a GWAS, which of the following would increase your chance of detecting a significant association between a disease phenotype and markers linked to the causal gene(s)?

The allele responsible for the disease arose from a mutation that occurred only once in the population and then increased to higher frequency by genetic drift. and The alleles responsible for the disease are tightly linked to some of the molecular markers used in the study.

Luria and Delbruck grew many liquid cultures of bacteria then spread a small sample of each culture on nutrient agar infused with bacteriophage in separate petri plates. They assayed the number of bacterial colonies that formed on each plate. In the Luria Delbruck experiment, what did the appearance of a bacterial colony on a petri plate indicate?

The bacterial colony was derived from one initial cell that was resistant to infection by the bacteriophage.

Which characteristic is typical of a cancer cell but not of a normal cell

The cell has the ability to invade surrounding tissue

immune surveillance

describes the ability of a person's immune system to identify newly formed cancer cells and to destroy them. The cells in successful tumors accumulate mutations that somehow allow them to evade this normal process of immune surveillance.

Which statement supports the theory that all organisms are related?

The genetic code is almost universal.

What is the relationship between chromosomal stability and proliferation?

The greater the chromosomal instability the higher the probability of getting cells that have a higher proliferation rate.

Which of the following is an example of a reporter gene?

The lacZ coding sequence under the control of a prokaryotic promoter

What would be the most likely result if a scientist removes mitochondria from a human cell and attempts to grow them in culture?

The mitochondria require the products of nuclear genes to function, so the mitochondria will die soon after being removed from the cell.

Why is a variegated plant considered heteroplasmic?

The plant has mutant and wild-type chloroplast DNAs distributed amongst the cells in different ratios. Correct

Select all statements that correctly describe bacteria that metabolize hydrocarbons, such as Alcanivorax borkumensis.

The population of these bacteria will increase when an oil spill occurs. Transferring genes from this species to other bacteria might allow other bacteria to break down oil. The genome of these bacteria encodes enzymes that allow hydrocarbons to be broken down for energy.

Assume that a new low-calorie sweetener is developed. Before being approved for human consumption, the mutagencity of the new molecule is determined with the AMES test. The results are shown Sample His-Bacteria+distilled water His-bacteria+ distilled water+rat liver enzymes His-bacteria+sweetener His-bacteria+sweetener+rat liver enzymes Number of colonies 3 2 4 65 What conclusion is most consistent with this data?

The sweetener is not mutagenic but can be converted into strong mutagens

What is a possible disadvantage of using genetically modified crops?

The transgene may make its way into wild plants.

What is one reason why tumor suppressor genes make poor drugable targets?

The tumor suppressor proteins may not even be produced.

One strain of rII- phage has a deletion in the rII region, another has a point mutation in the rII region. When E. coli K(λ) cells are infected with either rII- phage (not both) no plaques form. When E. coli K(λ) cells are infected with both rII- phage simultaneously plaques do form. Why do plaques form when E. coli K(λ) cells are infected with both types of rII- phage simultaneously?

The two phage have mutations in different rII genes and their genomes complement each other.

Which statement is true about the structure of DNA?

The two strands of a DNA molecule are held together by base pairing.

What is one problem associated with using retroviruses as human gene therapy vectors?

Their random integration into the host chromosome may result in detrimental mutations.

What is one problem associated with using retroviruses as human gene therapy vectors?

Their random integration into the host chromosome may result in detrimental mutations. Correct

A student analyzes a genomic DNA sequence of 100 nucleotides in order to determine if it is part of a gene. When she translates the sequence beginning at the first nucleotide, she finds that the tenth codon is UAA. What should she do next?

Translate the sequence in the other five reading frames.

A wild-type gene that is picked up by a retrovirus may be changed into an oncogene by mutation resulting from _____ _______ OR __________ ________ _________/___________

Viral replication OR near viral promoters/enhancers

dominant-negative or antimorphic mutation

a mutation that produces a protein that cannot perform the wild-type function and also prevents the normal protein from functioning

In transduction, the DNA is being moved between the two cells by

a phage

angiogenesis

a process whereby tumors stimulate the growth of blood vessels into the tumor so that the cancerous cells can be supplied with oxygen and nutrients.

If an organism is isolated that has no nuclear membrane and the DNA is condensed into a body in the cytoplasm, this organism would most likely be classified as

a prokaryote

To create transgenic mice, DNA is injected into

a pronucleus of a zygote.

To create transgenic mice, DNA is injected into

a pronucleus of zygote

metastasis/malignancy

a property of cancerous cells that allows them to escape into the bloodstream and thus to start secondary tumors in other parts of the body.

transcription factor

a protein that activates or represses transcription of specific genes to promote or inhibit cell division

signal transduction

a series of steps by which a signal is transmitted to and within a cell

gene amplification

a type of genomic instability in which the number of copies of particular chromosomal regions is increased. Gene amplification can result either in homogenously staining regions (HSRs), in which the additional copies are positioned in tandem with respect to each other at one location in the genome; or in multiple double minutes, small chromosome-like bodies lacking centromeres and telomeres. Gene amplification is particularly important to tumor progression if the region now found in additional copies includes a proto-oncogene.

genomic instability

describes the tendency of cancer cells to accumulate genomic changes at a rapid rate. These changes can include increased frequencies of point mutations, chromosomal rearrangements, aneuploidy, and even polyploidy.

What is the ploidy of a primary oocyte? What is the ploidy of a secondary oocyte?

diploid, haploid

Select all steps that occur during bacterial conjugation.

direct contact between donor and recipient cells shortening of the pilus enzymatic cleavage of one strand at the origin of transfer recipient cell becomes a donor cell after conjugation

Inversions may be difficult to detect because they

do not always cause an abnormal phenotype.

Sequencing of DNA from a tumor sample reveals that one allele of RB has been deleted and the other allele contains a missense mutation. The RB protein in the tumor cells most likely

does not bind to E2F, resulting in uncontrolled cell division.

The coding sequence of the green fluorescent protein gene (GFP) is placed under the control of an enhancer active in neurons. When this transgene is introduced into flies, GFP will be expressed in

all neurons or a subset of neurons.

By definition, linkage disequilibrium means that

alleles at separate loci occur together more than predicted by random chance.

a protein that changes its conformation upon binding to another molecule, such as a repressor that binds to an inducer.

allosteric protein

Oocyte nuclear transfer can be used to

allow women with mitochondrial diseases to have normal offspring.

A single eukaryotic gene can produce two different forms of a protein, one that is membrane bound and one that is secreted. Which of these mechanisms allows a single gene to produce two different proteins from one primary transcript?

alternative splicing

Which of these types of gene regulation occurs earliest in the process of gene expression?

alternative splicing

How can one primary mRNA result in several polypeptides with different amino acid sequences?

alternative splicing of exons

CRISPR sequences occur naturally as

an antiviral immune system in bacteria.

duplication

an increase in the number of copies of a chromosomal region

Fitness

an individuals relative ability to survive and transmit its genes to the next generation

Gene order can be inferred from gene expression patterns because

an upstream gene can affect down stream gene express

Which experiment would best determine which genes are expressed in a Drosophila embryo?

analysis of a cDNA library from Drosophila embryos

a nucleotide deletion during DNA replication

causes the amino acids encoded after the deletion to be incorrect

DNA mutations are passed on to the

cell's progeny

nonsense mutation

changes a codon specifying an amino acid into a stop codon

silent mutation

changes a codon without altering the amino acid that is encoded (for ex. GCA to GCC which both code for alanine

DNA sequences that are binding sites for transcription factors are called

cis-acting elements

complementation group identified by cis/trans test

cistrom

One way N. gonorrhoeae became resistant to penicillin was by acquiring a plasmid that carries the penr penicillin resistance gene, which encodes a protein that

cleaves penicillin to an inactive form.

Enhancers can be identified by

cloning a region of DNA with the putative enhancer in a reporter plasmid and demonstrating an increase in gene expression when the construct is introduced into a eukaryotic cell.

The F plasmid

codes for making the F pilus

Nonsense codons are

codons that do not code for an amino acid

Antibiotic resistance strains have become more ____ with the increased use of antibiotics in general.

common

Bacteria such as H. influenzae and N. meningitidis preferentially take up DNA that has a specific sequence that is ____found in their genomes.

commonly

The cell surface proteins that are necessary for bacteria to take up DNA from the environment are known as ______.

competence factors

Preferential uptake of DNA by S. pneumoniae is based on a high concentration of____which is secreted by the bacteria.

competence-stimulating peptide

uptake of DNA from external medium

competent

Cells that can take DNA up from the environment are referred to as _____.

competent cells

A phenotypic ratio of 9:7 in the F2 of a dihybrid cross may indicate

complementary gene action

when two different loss-of-function mutants with similar mutant phenotypes are crossed and their progeny are wild-type

complementation

a test that determines whether 2 mutations occur in a single generation or in 2 different genes

complementation test

Which method of fragmenting DNA would not be useful for sequencing a genome for the first time?

complete digestion with a restriction enzyme

requires at least one nutrient for growth

conjugation

DNA is transferred to the recipient cell through the

conjugation bridge

What would be the phenotype of a null mutation in the gene encoding Lac repressor

constitutive expression of the lac operon

a strain that synthesizes certain enzymes regardless of environmental conditions

constitutive mutant

What makes bacteria attractive for producing recombinant proteins?

cow juice quiz

UV light and other ionizing radiations damage DNA molecules by

creating thymine dimers between adjacent thymines in the DNA chain

The enzymatic activity of CDKs is regulated by forming a complex with which proteins?

cyclins

The ratio of ________ in DNA is 1:1.

cytosine and guanine OR adenine and thymine

in a tautomer shift, (a) it is always adenine that is changed (b) bonding of bases ultimately remains unchanged (c) adenine is changed so it can no longer form base pairs (d) hydrogen atoms move from a base with altered hydrogen properties (e) carbon atoms move to form a base with altered properties

We isolate nine different mutants unable to make histidine. They map in different locations and by genetic means we can show there are nine different genes in the pathway. How many enzymes can we anticipate finding in this pathway? a. 1 b. 3 c. 6 d. 9 e. 12

d. 9

What is a typical characteristic of a bacterial chromosome? a. 5% of the sequence encodes proteins b. it has telomeres c. it is linear d. on average a gene occurs in every 1000 bp

d. on average a gene occurs in every 1000 bp

G to S checkpoint

delays DNA replication if damage to DNA has occurred

Knockin mice can be created using the Cre/loxP system. In this procedure, the loxP sites are used to

delete the neomycin-resistance marker gene.

The type of mutation that results in a loss of material from the genome is called what?

deletion

loss of a block of one or more nucleotide pairs

deletion

What type of mutations does the mutagen intercalating agents generate

deletions

What type of mutations does the mutagen x-rays generate

deletions

you are studying a histone complex that contains an unusually high level of modification with acetyl groups. What can you conclude about the DNA bound to this histone complex?

It contains actively transcribed genes.

The presence of a homeodomain in a protein suggests what about its function?

It is a transcription factor

The presence of a homeodomain in a protein suggests what about its function?

It is a transcription factor.

Which statement best describes the limitations of using of humans in genetic studies of developmental biology?

It is impractical and unethical to conduct experimental manipulation or targeted mutagenesis of humans to examine the role of genes in development.

A mutation that results in production of a mutant protein with only one amino acid change can result in

dramatic difference in phenotype

What type of mutation adds material to the genome?

duplication

Methylated histone tail amino acids are associated with chromatin that is

either open or closed

If a chemical inhibitor of DNA ligase was added to bacterial cells after DNA replication initiation, the outcome would be __.

elongation would occur, but Okazaki fragments would not be joined together.

a cis-acting DNA sequence that may function at a distance from the gene they are regulating

enhancer

The sequences found in a mature eukaryotic mRNAs are

exons

The Aniridia gene in humans is involved in eye formation. Although eye development is very different in flies, this gene is highly conserved. What is the Drosophila homolog of Aniridia?

eyeless

F+ refers to a cell containing

f plasmid

A PCR using a single pair of primers produces many copies of the entire genome.

false

Multidrug resistance is not a major health concern because new antibiotics are easily and frequently identified.

false

Plasmids are created exclusively in research laboratories and do not occur naturally.

false

True or False? Genome-wide associations studies (GWAS) are applied to discrete traits (e.g., presence or absence of a disease) but not to continuous traits (e.g., height).

false

What does biological ancestry describe?

family trees or pedigrees

an experiment performed by Luria and Delbrück to determine when resistance mutations occurred

fluctuation test

gene pool

total of the alleles of all the individuals in a population

As a general principle of gene regulation through operons, regulatory genes encode

trans-acting proteins that interact with cis-acting DNA elements

Which of these processes are coupled in prokaryotes but NOT in eukaryotes?

transcription and translation

The different tRNAs are produced by

transcription of different tRNA genes in the genome.

Which of the following is required for initiation of eukaryotic translation?

transcription quiz

a result of heterochromatin formation

transcriptional silencing

E. coli strain with F factor integrated into bacterial genome

transduction

When genetic transfer between bacterial cells occurs because a bacteriophage transfers bacterial DNA from one bacterium to another.

transduction

Select all examples of vertical gene transfer.

transfer of DNA into bacterial cells during cell division transfer of DNA by gametes in a sexually reproducing organism

F factor that has picked up a piece of the bacterial genome

transformation

Two F+ E. coli strains are co-cultured in the same flask. One is Strr Thr+ and the other is Genr Thr−. The culture is then plated on minimal media that is supplemented with gentamicin only (not threonine) and a few colonies grow. What sort of genetic exchange is most likely occurring? Note: Strr = streptomycin resistant; Genr = gentamicin resistant; Thr+ = able to synthesize threonine (essential for growth); Thr− = unable to synthesize threonine.

transformation

Which form of genetic transfer involves competence factors?

transformation

If this mRNA is transcribed in the nucleus and translated in the cytoplasm, what amino acid sequence is encoded? (photo in hw)

translation will not begin

all DNA segments that move about in a genome, regardless of mechanism

transposable element

chemotherapy

treating cancer patients with drugs that kill cancer cells.

Bacteria that live in extreme environments, such as thermal vents on the ocean floor, have evolved genes that allow them to use the resources within that environment.

true

Chemical agents can cause mutations by inducing methylation of guanine residues in DNA

true

This population is in Hardy-Weinberg equilibrium. (required info: Brachydactyly is a condition caused by an allele dominant to wild-type in humans, in which the fingers and toes are shortened. In a population of 10,000 people, 1,600 are BB, 4,800 are Bb, and 3,600 are bb)

true

How many replication forks depart from an origin of replication?

two

A chromosome of genotype C D recombines with a homolog of genotype c d during meiosis when Spo11 produces a double-strand break between the two loci. If anticrossover helicase disentangles the invading strand, the likely outcome would be __.

two C D and two c d gametes.

Host genes that are closest to the F plasmid sequences may either be the most or the least likely to be transferred as transfer is in a _____ manner.

unidirectional

How would you best follow the timing of expression of a given protein during development in a live animal?

using a transgenic organism that expresses a GFP fusion protein

A phage that follows the lytic cycle

virulent phage

A bacteriophage is a

virus that infects a bacterium.

A bacteriophage is a

virus that infects bacteria

Complementation studies can be performed in bacteria by

forming merodiploids with one copy of a bacterial gene on an F′ plasmid

A mutation that changes a wild-type allele to a mutant allele

forward mutation

A DNA sequence 5′ ATGGGGGACACC 3′ encodes the amino acids Met Gly Asp Thr. A mutation changes the sequence to 5′ ATGAGGGGACACC 3′ that encodes the amino acids Met Arg Gly His. What type of mutation has occurred?

frameshift

frameshift mutation

proto-oncogene

gain of function mutant alleles act dominantly and contribute to cancer

The protein that progressively unwinds DNA ahead of each replication fork is called __.

helicase

a complex of two different subunits

heterodimer

Without __________ regions of the DNA during recombination, gene conversion could not occur.

heteroduplex

Researchers at the Ministry of Magic decide to measure the heritability (h2) of horn length in two populations of unicorns. One of the populations lives in the Forbidden Forest; these unicorns are well-cared for by Hagrid, who protects them from unicorn poachers, nurses them to health when they are sick, heals their wounds, and makes sure they are well-fed. The other population lives in the mountains of Albania, where they are in constant danger from poachers (who kill them for their blood and their horns), must survive harsh winters, and often do not have enough to eat. Would you predict that the heritability of horn length would be higher in population 1, higher in population 2, or approximately the same in the two populations?

higher in pop 1

Two identical Jun polypeptides associate with each other via their leucine zippers to form an active transcription factor. What is the transcription factor called?

homodimer

a complex of two identical subunits

homodimer

Recombination involves the breakage and reunion of DNA molecules from

homologous nonsister chromatids.

Maternal effect mutations can be identified when

homozygous mutant females can develop normally, but their offspring exhibit a mutant phenotype

maternal effect mutations can be identified when

homozygous mutant females can develop normally, but their offspring exhibit a mutant phenotype

Maternal effect mutations can be identified when

homozygous mutant females can develop normally, but their offspring exhibit a mutant phenotype.

Antibiotic resistance bacteria may arise through ____.

horizontal gene transferred

the proofreading function of DNA polymerase reduces the error rate from about one in a million basepairs to about on in _____________ basepairs

hundred million

The bonds between bases on opposite DNA strands that are responsible for holding the two strands of a double-stranded molecule together are called

hydrogen bonds

Thymine dimers weaken

hydrogen bonds

Many cancers have a mutation that changes a valine to a glutamic acid in the RAF kinase protein, which phosphorylates proteins that promote cell division. This mutant protein is a constitutively active kinase. What type of allele is this mutant allele?

hypermorphic

Mutations that result in much less of a protein or a protein with limited function are known as

hypomorphic

Mutations that result in the production of much less of a protein or a protein that functions less efficiently than wild type are

hypomorphic mutations

Inversions are most likely to affect an organism's phenotype

if one or both of the inversion's breakpoints lies within the transcribed region of a gene.

describes a pattern of inheritance in which expression depends on which parent transmitted the allele

imprinting

The transfer of DNA from an Hfr cell starts at the oriT and will ___ at least some host DNA

include

Which is a characteristic of retrotransposons, but not of DNA transposons?

include a gene that encodes reverse transcriptase

Patients who have a defect in one of the DNA repair systems may have what?

increased number of skin lesions, such as freckles and increased chance of cancer

Genetic testing for cancer can

indicate increased risk of certain cancers.

stimulation of transcription by a specific molecule

induciton

Inhibitors of bacterial translation, such as chloramphenicol and erythromycin, usually

inhibit mitochondrial protein synthesis, inhibit chloroplast protein synthesis

Penicillin stops bacterial cell wall formation by

inhibition of a transpeptidase.

addition of a black of one of more nucleotide pairs

insertion

frameshift mutation

insertion or deletion of a number of nucleotides that is not divisible by three

Hfr refers to a cell that has

integrated the F plasmid into its genome.

flat planar molecules that sandwich between DNA bases

intercalators

180 degrees rotation of a segment of a DNA molecule

inversion

What are the four major classes of chromosomal rearrangements?

inversions, duplications, translocations, deletions

The ends of an insertion sequence (IS) element contain

inverted repeats.

The F pilus

is a protein appendage on the F+ donor that attaches to specific receptors on the cell wall of the recipient

To produce a mutation in a specific E. coli gene, an engineered fragment of DNA in which sequences from each end of that gene flank an antibiotic resistance gene,

is introduced into cells and undergoes homologous recombination with the bacterial gene.

When the phage DNA integrates into the host genome. No new phage are made. This is a dormant state for the phage.

lysogenic cycle

A codon is a three-base sequence of

mRNA that codes for an amino acid

growth factor receptors

molecules embedded in the membranes of receptive cells that are targeted by growth factors. The binding of a growth factor to a growth factor receptor at the surface of a cell initiates a signal transduction pathway/cascade that eventually influences the activity of transcription factors within the cell's nucleus. These transcription factors regulate the transcription of genes whose products either promote or inhibit cell division.

signal transducers

molecules that act as intermediaries within signal transduction pathways to transmit the signal (the binding of a growth factor to a growth factor receptor at the cell surface) to the effectors of the pathway (the transcription factors that regulate the expression of genes whose products are involved in cell division).

growth factors

molecules that promote or inhibit cell proliferation; those that promote cell division are mitogens. Hormones are mitogens that are produced by one cell type but act on other cell types.

What feature of a DNA microarray analysis allows the number of copies of a particular sequence in the genome to be inferred?

more copies of a sequence result in a higher intensity signal

any agent that can cause mutations at a frequency higher than the spontaneous rate

mutagen

Which of the following mutant alleles is most likely to be dominant to the wild-type allele?

mutations quiz

When DNA is damaged by UV light and is not repaired,

neither DNA replication more transcription can occur and the organism will probably die.

the hypothesis proposed by Beadle and Tatum

one gene, one enzyme

Acetylated histone tail lysines are associated with chromatin that is

open.

a cluster of genes transcribed together into a single mRNA and regulated as a group

operon

The Hardy-Weinberg equation is best at predicting short term genotypic frequencies since

over the long term some of the assumptions of the equation will not be true

The human papilloma virus (HPV) carries a gene that functions as an oncogene by inactivating the p53 protein. The fact that the loss of p53 function is oncogenic suggests that

p53 normally functions to prevent uncontrolled cell division.

biological ancestors

parentage

Biological ancestry describes the

parentage and not shared genes.

Improper base-pairing during DNA replication causes a

pause in chain elongation

The proportion of individuals in a population that are of a particular phenotype is the

phenotype frequency

During DNA replication, an incoming nucleotide is enzymatically joined to the preceding nucleotide by a(n) ___ bond.

phosphodiester

Alters a proteins activity, stability, or localization

phosphorylation

A karyotype of chromosomes from a cancer cell would be most likely to exhibit

polyploidy

The loss of allelic variation due to an event that decreases the size of the entire population is called

population bottleneck

What is the term for the loss of genetic variation due to an event that decreases the size of the entire population?

population bottleneck

A bacterium is found that is resistant to the antibiotic gentamicin. The bacterium was isolated in a hospital where patients were routinely given gentamicin for a variety of infections. What was the pressure that selected for this resistant population?

presence of gentamicin in the environment

Extranuclear genes show a biparental inheritance pattern in yeast since

progeny from diploid vegetative growth can have the phenotype of either the a or the α parent.

If an organism is isolated that has no nuclear membrane and the DNA is condensed into a body in the cytoplasm, this organism would most likely be classified as a

prokaryote

if an organism is isolated that has no nuclear membrane and the DNA is condensed into a body in the cytoplasm, this organism would most likely be classified as a a. prokaryote b. eukaryote c. archaea d. could be a eukaryote or prokaryote

prokaryote

The name of the cis-acting DNA sequence at which the transcriptional initiation complex forms

promoter

RNA polymerase binds to the

promoter.

cyclins

proteins that combine with kinases to direct kinase activity to particular substrates during the cell cycle

capable of growth on minimal medium

prototrophic

a mechanism of indirect repression in which a repressor binds to an activator that is bound to an enhancer

quenching

A prokaryotic large ribosomal subunit is composed of

rRNA and protein

The pattern or sequence in which a molecule of mRNA is deciphered by a ribosome is the

reading frame

Which of the following terms best describes a bacteria that has had its genotype changed by transduction?

recombinant cell

The process of ________ is extremely important in generating genetic diversity.

recombination

The CDK-cyclin D complex phosphorylates RB, which then

releases E2F to activate genes for DNA synthesis.

deletion

removal of a segment of DNA

What occurs during plasmid excision in Hfr cells?

removal of the plasmid from the bacterial chromosome

A gene fusion where the regulatory region of one gene is fused to the open reading frame of another gene whose protein product is easy to detect

reporter gene

prevention of gene expression by a specific protein that binds to an operator

repression

What is the term for transcription factors that decrease transcriptional activity?

repressors

A mutation that changes a mutant allele back to a wild-type

reverse mutation

personalized cancer treatment

tailoring cancer treatments to the individual, based upon the suite of mutations in oncogenes and tumor-suppressor genes found by comparing the genomic sequences of tumor tissues and normal tissues in that patient.

Which does a successful PCR require?

some sequence information about the region to be amplified

crops that are gmo in the us

soybeans, summer squash, corn, papaya, potato, apple

Drugs such as Gleevec and Herceptin represent a modern approach to cancer treatment since they

specifically target gene alterations that occur in some cancers.

Drugs such as Gleevec and Herceptin represent a modern approach to cancer treatment since they

target specific gene alterations that occur in some cancers

A bacteriophage that normally exists in the lysogenic cycle.

temperate phage

The Rho protein is involved in which stage of transcription?

termination

To create a knockout mouse, after introducing to ES cells a DNA construct in which a specific gene is mutagenized by the insertion of a drug resistance marker, the cells

that have incorporated the transgene by homologous recombination grow in the presence of the drug and these are injected into a host blastocyst.

The wobble base of a tRNA is

the 5′ base of the anticodon.

F+ refers to a cell containing

the F plasmid.

In forensics analysis 13 loci are types and the probability of finding an individual in a population with that specific combination of SSR types calculated based on

the Hardy-Weinberg Law

A change of one base for another, different base

substitution

What type of mutations does the mutagen Base analogs generate

substitutions

What type of mutations does the mutagen alkylating agents generate

substitutions

What type of mutations does the mutagen delaminating agents generate

substitutions

What type of mutations does the mutagen hydroxylating agents generate

substitutions

Which one of the following is not an element found in DNA? oxygen, sulfur, hydrogen, nitrogen, phosphorus

sulfur

In Sanger sequencing, the role of the DNA polymerase is to

synthesize new DNA that is complementary to the template strand.

cancer landscapes

tabulations of the mutations in the cancer cells from many patients. Knowledge of such landscapes help scientists determine both what phenotypes are likely to occur when particular suites of oncogenes and tumor-suppressor genes are mutant, and what kinds of drugs are most likely to be successful in treating specific subclasses of tumors

what causes a frameshift mutation

the addition of a single base pair to a gene's DNA sequence

The sequence of bases in mRNA is determined by

the base sequence in DNA

The mutations found in the CF gene that result in cystic fibrosis are recessive because

the protein produced by the normal allele is sufficient for normal cellular function.

druggable targets

the protein products of genes that have been mutated in cancer cells. Most druggable targets are the proteins encoded by oncogenes.

Exposure to UV light from the sun or tanning beds causes __.

thymine dimers

F prime strain

F plasmid contains some of host chromosome

pangenome

- consists of about 15,000 genes - genes that are found in some but not all E coli strains - allow strains to adapt to different environments

Short-limb dwarfism in humans is caused by a missense mutation in the human FGFR3 gene, resulting in a gain-of-function, constitutively active FGF receptor protein. Select all steps that would occur to produce a mouse model of this form of dwarfism.

- A construct with a nonsense mutation in FGFR3 is created. - The mutant DNA integrates into a random location in genomic DNA in a mouse pronucleus. - LoxP sites undergo recombination to delete the targeted exon of the mouse FGFR3 gene. - A knockin mouse with the human FGFR3 missense mutation is larger than wild-type littermates.

Which of the following are steps in the generation of knockout mice using ES cells?

- Add LTRs to the ends of a cDNA for the gene to be knocked out. - Introduce a gene-targeting construct into host blastocysts. - Mix modified ES cells with ES cells containing a Cre gene. - Introduce a gene-targeting construct into packaging cells. - Replace the viral genes with a therapeutic gene.

Select all examples of metagenomic research projects.

- Genome sequencing of multiple strains of a bacterial species differentiates between the core genome and the pangeome. - The existence of germ-free mice demonstrates that microbes are not beneficial for mammals.

Which of the following are limitations of DNA polymerase?

- It can only add bases to the exposed 5' end of a preexisting strand. - It can only replicate the leading strand. - It can only replicate the lagging strand. - It can only replicate circular chromosomes.

LHON is a mitochondrial disease caused by weak hypomorphic mutations that affect the mitochondrial electron transport chain. Among the first symptoms of the disease is blindness. People with LHON are usually homoplasmic because retinas must be homoplasmic mutant for a person to have disease symptoms. Which is true about a female who is heteroplasmic for the mutation that causes LHON?

- She is likely to develop the disease in other parts of her body. - All of her children will be homoplasmic for the wild-type mitochondria.

What is true about reciprocal translocation heterozygotes and inversions?

- The amount of DNA in the genome remains the same. - The genes at the boundaries may be disrupted, while those in the middle are most likely unaffected. - Up to 50% of gametes may be unbalanced, resulting in semisterility.

A man who had colon cancer has an aunt who also had the same type of colon cancer. The man's son has just been diagnosed with the same type of colon cancer and doctors perform genome sequencing of his cancer cells and normal cells. If this cancer is associated with an inherited mutation, select the expected results of genome sequencing.

- The cancer cells have two loss-of-function alleles of an oncogene. - His normal cells are heterozygous for a gain-of-function allele of an oncogene.

core genome

- consists of about 1000 genes - genes that are common to all E coli strains - provide essential functions

genomic library

- a collection of cellular clones that contains copies of every sequence in an organism's whole genome inserted into a suitable vector - all regions of the genome are represented in a complete library - a single library may contain the whole genome

cDNA library

- a collection of sequences copied into DNA from all the mRNA transcripts present in a particular cell type, tissue, or organ - reveals the fraction of the genome in a specific tissue that is transcribed and teh genes whose primary RNAs are processed into mRNAs - reverse transcriptase copies mRNA into a complementary DNA strand - a unique library can exist for every tissue in an organism - the frequency with which particular sequences appear is proportional to the level of the corresponding mRNA

self-fertilization

- a cross where the pollen of one plant is used to fertilize the ovum of the same plant - this cross is impossible in species where individuals are the same sex

opens chromatin and promotes gene expression

- histone acetyl transferase - histone methyltransferase - histone demethylase

closes chromatin and inhibits gene expression

- histone deacetylase - histone methyltransferase - histone demethylase

transposons

- inverted repeats at the ends are recognized by transposase - contains a gene that encodes transposase - a copy of the element may or may not remain at the original location depending on the template - transposase removes the element and inserts it into a new location - gaps that remain after movement are repaired using a sister chromatid or homologous chromosome as template

cross-fertilization

- reciprocal crosses are possible - testcrosses are possible - a cross where the pollen of one plant is used to fertilize the ovum of a different plant

retrotransposons

- transcribed by RNA polymerase to produce an RNA that encodes reverse transcriptase - some of these have long terminal repeats (LTRs) at both ends, in the same orientation - some of these have a poly-A tail at the 3' end of the RNA like DNA strand - reverse transcriptase produces a double stranded cDNA copy that is inserted into a new location

LHON is a rare mitochondrial disease caused by weak hypomorphic mutations that affect the mitochondrial electron transport chain. The first symptoms of the disease include blindness. People with LHON are usually homoplasmic because retinas must be homoplasmic mutant for a person to have disease symptoms. Which is true about a male who is heteroplasmic for the mutation that causes LHON?

-All of his children will most likely be homoplasmic for the wild-type mitochondria. -Some cells in his body are probably homoplasmic.

Which are possible results of an intragenic inversion (an inversion contained within a gene)?

-All of the gene's A, C, G, and T bases remain in the same order as normal. -The order of genes along the chromosome may be different than normal.

In what way can defective transposable elements alter genomes even if they cannot mobilize?

-Crossing-over between transposable elements on the same chromosome can result in a deletion or an inversion. -Crossing-over between transposable elements on nonhomologous chromosomes can result in a reciprocal translocation.

Select all statements that describe the relationship between telomerase and cancer.

-Telomeres in cancer cells are typically shorter than telomeres in the somatic cells of the same individual. -Cells with a deletion of the gene that encodes a telomerase protein are more likely to become cancerous. -Telomerase is a complex of DNA and protein.

-The cancer cells have two loss-of-function alleles of an oncogene. -His normal cells are heterozygous for a gain-of-function allele of an oncogene.

Which is true of enhancer DNA sequences?

-They contain TATA boxes. -They only function to increase gene transcription levels above the basal level.

Which can result in Down syndrome?

-deletions of a segment of chromosome 21 -having the triploid number of chromosomes

A pathogen is a bacterial strain that can cause disease in the host organism.

A pathogenic bacterium can become multidrug-resistant when it obtains a plasmid from another species of bacteria that infects the same patient.

Approximately 90% of E. coli DNA codes for proteins and there is an average of one gene in every kilobase of DNA

Bacteria that cause disease in humans can invade tissue and produce toxins

Bacterial cell walls are composed of peptidoglycan consisting of N-acetylglucosamine and N-acetylmuramic acid.

Bacterial cells walls are synthesized in part by transpeptidase which creates cross-links using a small peptide.

Bacterial genomes contain small transposable elements termed insertion sequences (ISs) that resemble transposons of eukaryotic cells.

Brain cells in patients with Alzheimer's disease have lower energy metabolism than normal and 20%-35% of the mitochondria carry loss-of-function mutations in two of the three cytochrome c oxidase genes.

Clostridium tetani produces a protease that inhibits neuro-muscular communication.

In slime molds, RNA editing adds cytosines. In plants, RNA editing converts cytosines to uracils

In the E. coli genome, some predicted genes encode proteins with functions that have not yet been determined; these presumed genes are called open reading frames (ORFs)

Many plasmids with antibiotic resistance genes also have IS elements that allow several resistance genes to transpose together.

Most of the bacteria that inhabit the human gut are harmless or beneficial.

N. gonorrhoeae can become resistant to penicillin by acquiring a plasmid with the gene encoding penicillinase.

Over time, mitochondria accumulate mutations that may lead to a decline in cellular metabolism, which may cause age-related decreases in heart and brain function.

Oxidative phosphorylation produces high levels of DNA-damaging free radicals in mitochondria

Penicillin inhibits transpeptidase, which is only produced in bacterial cells

Plasmids are circular extrachromosomal genetic elements that replicate independently of the host genome and can be used as cloning vectors.

Plasmids can carry genes that confer resistance to heavy metals or antibiotics or genes that allow the cell to metabolize chemicals or produce toxins.

RNA editing uses guide RNAs encoded by the minicircles as templates for adding or deleting uracils to convert the pre-mRNAs to mature mRNAs.

RNA editing was discovered in the specialized mitochondrion called the kinetoplast of trypanosomes.

Resistance in N. gonorrhoae can occur through mutations in several genomic genes including a transcription factor known as MtrR.

Sequencing demonstrated that the maxicircles contain genes that encode pre-mRNAs.

The E. coli genome also contains remnants of bacteriophage (viral) genomes, suggesting certain evolutionary events.

The bacterial chromosome is a single double-stranded DNA molecule

The enzymes involved in pre-mRNA editing are organized into a complex called the editosome

The pre-mRNAs cannot be used to produce proteins because they lack start or stop codons

The process of metagenomics takes samples from a particular ecological environment and analyzes all DNA present to determine sequences that are present in the habitat or community as a whole.

This may explain the higher rate of mutation seen in human mitochondrial genes than in nuclear genes.

ome bacteria carry plasmids, which are extrachromosomal circles of double-stranded DNA.

In humans, brachydactyly is a dominant condition; 6,400 people in a population of 10,000 show the disease (1,600 are BB, 4,800 are Bb) and 3,600 are normal phenotypes (bb). The frequency of the b allele is

0.6

What is the frequency of the b allele?What is the frequency of the b allele? (required info: Brachydactyly is a condition caused by an allele dominant to wild-type in humans, in which the fingers and toes are shortened. In a population of 10,000 people, 1,600 are BB, 4,800 are Bb, and 3,600 are bb)

0.6

What is the correct order of these events in recombination that is resolved by the crossover pathway? 1. Double-strand break formation 2. Strand invasion 3. Resection 4. Resolution of the double Holliday junction 5. Branch migration 6. Formation of a double Holliday junction

1, 3, 2, 6, 5, 4

Arrange these steps in the proper order, from first to last, in which they occur during a single PCR cycle.

1. Heat denaturation of strands of target DNA 2. Hybridization of primers to target DNA 3. Addition of deoxyribonucleotides by DNA polymerase

Lederberg and Tatum

1. If bacteria in same tube genotype is altered. 2. Control of single strain in tube did not result in change of phenotype 3. Agar plates select for transfer of genes

Intergenic Mapping

1. Mapping the distance between two genes 2. Phage used in this type of mapping will show complementation

Intragenic Mapping

1. Mapping the distance between two mutation in one gene 2. Number of wild type phage produced is dependent on how far apart mutations are 3. Mapping distances are calculated on the number of recombinants produced 4. Phage used in this type of mapping will not show complementation

Order the steps in the production of a transgenic mouse from first (1) to last (5).

1. Zygotes are harvested from a recently mated female mouse. 2. Linear copies of the transgene DNA are injected into a pronucleus of a fertilized egg. 3. Tandem copies of DNA integrate into a random location on a chromosome. 4. Mice that were injected as embryos are born from a host female. 5. Cells from mouse tails are tested for transgenic DNA.

In a group of 100,000 people, about how many would be expected to have the same genotype as the crime scene sample? For simplicity, assume all SSR alleles are present in the population at a frequency of 0.2.

Suppose the experiment of Meselson and Stahl was performed on a sample of 8 cells, each containing one copy of its circular double-stranded DNA genome, and that had been growing on normal 14N medium. You then grew the cells for 3 generations in medium containing 15N. The outcome would be __.

16 cells with double-stranded DNA molecules with equal amounts of 14N and 15N, and 48 cells with double-stranded DNA molecules with 15N.

In Drosophila, the recessive allele for forked bristles is sex-linked, and the recessive allele for purple eyes is autosomal. The wild-type alleles are for straight bristles and red eyes, respectively. A female, heterozygous for both pairs of alleles, is mated with a male with forked bristles and purple eyes. What percentage of the daughters will have forked bristles and purple eyes?

25%

Suppose the L and M genes are on the same chromosome but separated by 100 map units. What fraction of the progeny from the cross L M / l m × l m / l m would be L m / l m?

25%

Which genotypic ratio indicates a recessive lethal allele when two heterozygotes are mated?

2:1

Fruit flies normally have red eyes. Seven different true-breeding strains of fly with white eyes have been identified (A-G). In each strain, the white eye trait is due to an autosomal recessive allele. it is possible all seven strains have mutations in different genes. To determine how many genes are involved in eye color in these flies, pair-wise crosses are performed between each strain. The offspring phenotypes resulting from each cross are observed. (+=wild-type; - = mutant) A B C D E F G A - - + + - + + B - + + - + + C - - + + + D - + + + E - + + F - - G - Based on these crosses, how many different eye color genes are mutant in all of these strains collectively?

The genetic code includes how many stop/start codons

3 stop, 1 start

DNA polymerases use their ________ activity to remove a mismatched base

3' to 5' exonuclease

If a single DNA molecule is amplified by PCR, how many DNA molecules will exist after FIVE cycles?

The trp operon consists of five structural genes. In the absence of tryptophan, how many proteins are produced from this operon?

An anticodon of sequence 5′ GUA 3′ will recognize the codon sequence

5' UAC 3'

34. The genetic condition xeroderma pigmentosum, which can lead to skin cancer, results from: A) inability to correct UV induced dimers. B) inability to process phenylamine. C) inability to produce functional hemoglobin. D) inability to correct transitions. E) breaks in the X chromosome.

41. Genes on the X chromosome of mammals and Drosophila are particularly suitable for genetic study because: A) males have only one X and most genes behave as haploids. B) females have only one X and most genes behave as haploids. C) the X chromosome is large and many more genes are located there. D) when present as Barr bodies they are exposed for electron microscopic examination. E) they behave as diploids in females.

21. A mutation in which parts of two nonhomologous chromosomes change places is called a: A) translocation. B) transition. C) transversion. D) insertion. E) deletion.

24. Which type of mutation is least likely to revert? A) deletion B) transition C) transversion D) insertion E) all are equally likely

29. The hydrolysis of a purine base from the deoxyribose-phosphate backbone is called: A) depurination. B) deamination. C) replica plating. D) excision repair. E) deletion.

46. In the Ames test for mutagenicity: A) auxotrophic bacteria are converted to prototrophs which survive. B) prototrophic bacteria are converted to auxotrophs which survive. C) cells are treated with mutagen and only those with no mutations survive. D) cells are treated with excess amino acids, killing cells that carry mutations. E) rat liver enzymes protect cells from mutation.

54. Shown below are the results of a series of coinfections using T4 rII- strains similar to those employed by Benzer. Each strain contains a different deletion mutation. Ability to produce wild-type progeny phage is indicated by (+), (o) indicates no wild-type progeny. A B C D E A o + o + + B + o + o o C o + o + + D o o + o + E + o + + o A) CADBE B) ACBDE C) ABCDE D) BEDCA E) CEADB

59. Shown below are the deletion maps of a series of rII- mutations. The deleted region is indicated as (......) and the intact region as ______. Note that strain 5 carries two different deletions. 1 ___________(...........)_______________ 2 _________________(...........)_________ 3 (.....................)_______________ ______ 4 ________________________(................) 5 _____(..........)________________(.........) A series of point mutations A-E is used in a coinfection experiment. Shown below are the results of those coinfections. Ability to produce wild-type progeny phage is indicated by (+), (o) indicates no wild type progeny. 1 2 3 4 5 A + + o + o B + o + + + C + + o + + D o + + + + E + + + o o Indicate the order that is most consistent with these data. A) CADBE B) DEBAC C) BADCE D) ABDEC E) CEADB

70. Consider the pathway for the synthesis of the amino acid arginine in Neurospora: ARG-E ARG-F ARG-H ornithine citrulline argininosuccinate arginine Mutant strains of Neurospora are grown in minimal media supplements as follows. Each mutant strain carries only a single mutation. Growth is shown by (+), no growth is shown by (o). Supplements mutant nothing ornitihine citrulline arginino- arginine strain succinate a o o o + + b o o + + + c o o o o + Indicate the correct strain / defective gene pairing. A) strain a / ARG-F B) strain a / ARG-H C) strain b / ARG-F D) strain c / ARG-E E) strain c / ARG-F

71. Consider the pathway for the synthesis of the amino acid arginine in Neurospora: ARG-E ARG-F ARG-H ornithine citrulline argininosuccinate arginine Mutant strains of Neurospora are grown in minimal media supplements as follows. Strains may carry more than one mutation. Growth is shown by (+) no growth is shown by (o). Supplements mutant nothing ornitihine citrulline arginino- arginine strain succinate a o o o o + Indicate the most accurate statement regarding strain A. A) There is a mutation in ARG-H, if citrulline accumulates, ARG-F is also defective. B) There is a mutation in ARG-H, if ornithine accumulates, ARG-F is also defective. C) There is a mutation in ARG-H, if argininosuccinate accumulates, ARG-F is also defective. D) There is a mutation in ARG-H, if citrulline accumulates, ARG-E is also defective. E) There is a mutation in ARG-E, if citrulline accumulates, ARG-F is also defective.

78. 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 molecules of an individual with sickle cell anemia clump together. D) The red blood cells of an individual with sickle cell anemia distort and elongate. E) All of the above are true regarding sickle cell anemia.

83. Mutations that abolish the function encoded by the wild-type allele are known as: A) null mutations. B) hypomorphic mutations. C) hypermorphic mutations. D) conditional mutations. E) neomorphic mutations.

87. Examination of the rhodopsin gene family provides evidence for gene evolution by: A) duplication and divergence. B) accumulation of random mutations. C) convergent evolution. D) spontaneous generation. E) drift.

A null allele can be dominant to the fully functional wild-type allele due to: A) haploinsufficiency B) codominance C) incomplete dominance D) neomorphism E) not true, a null allele is always recessive to a fully functional wild-type allele

Gene evolution is best illustrated by: A) the rhodopsin gene family B) inborn errors of metabolism C) X-linked traits D) sickle cell anemia E) xeroderma pigmentosum

In an Ames test for mutagenicity, rat liver enzymes are accidentally excluded from the compound under test. What can you say about the results? A) the mutation rate will probably rise B) the mutation rate will probably decline C) the results are less relevant to mammals D) the results are less relevant to bacteria E) no mutations will form

Loss of heterozygosity

A cell with one mutant tumor suppressor allele acquires a second loss of function mutation in the wild type allele

genetic drift

A change in the allele frequency due to random sampling from one generation to the next

Cyclic-dependent protein kinases

A class of cell cycle enzymes that phosphorylate proteins

Growth factors

A hormone or a cell bound signal that stimulates or inhibits cell division upon binding a membrane receptors

Which is not an example of euploidy?

A human with Down syndrome has three copies of chromosome 21.

What was "The Berg Letter"?

A letter by Paul Berg, Herbert Boyer, and Stanley Cohen, published in 1974 in the journal Science, urging scientists to refrain from doing any recombinant DNA research until potential hazards could be investigated, and safety measures put in place.

A strain of penicillin-resistant N. gonorrhoeae that does not have a plasmid is isolated. A lysate made from the bacterium cannot degrade penicillin in an in vitro assay. When a culture of this strain is grown in a solution that contains radioactive penicillin, the amount of penicillin found within cells is less than the amount found within cells from a nonresistant strain. The DNA sequence of the porin gene from the resistant strain does not have any mutations. What is the most likely mechanism of resistance in this strain?

A mutation in the mtr gene has occurred, resulting in fewer efflux pumps

Transcription factors

A proteins that activates or represses transcription of specific genes to promote or inhibit cell division

How can transgenic organisms be used to identify transcriptional enhancers?

A reporter gene can be constructed so that its expression is controlled by an enhancer that may potentially exist within a fragment of genomic DNA

How can transgenic organisms be used to identify transcriptional enhancers?

A reporter gene can be constructed so that its expression is controlled by an enhancer that may potentially exist within a fragment of genomic DNA.

Signal transduction

A series of steps by which a signal is transmitted to and within the cell

tumor-suppressor gene

A tumor-suppressor gene encodes a product that impedes cell cycle progression or that protects the genome from alterations. Loss-of-function mutations in tumor-suppressor genes promote cancer.

Viruses are isolated from wild-type E. coli cells that have been infected with wild-type bacteriophage λ. These viruses are used to infect a Gal− strain of E. coli. A few bacterial colonies that can grow on galactose are obtained, while no bacteria that can grow on galactose are obtained from cells that were not infected. What has happened?

A λ gal+ phage was generated.

The ________ codon is used as the start codon by nearly all organisms.

AUG methionine

Assume that a series of compounds has been discovered in Neurospora. Compounds A-F appear to be members of an enzyme pathway. Several mutations have been identified and each of strains 1-4 contains a single mutation. Shown below are five possible pathways. Choose the pathway that best fits the data presented. [Growth in minimal media with supplements is shown by (+), no growth is shown by (o)] media supplement strain A B C D E F 1 o o o + o o 2 o o o o o + 3 o o o o + + 4 o o + o o o

A->B->C->D | E->F

What is a characteristic that is typical of a cancer cell but not of a normal cell?

Ability to invade surrounding tissue.

Select all characteristics of repressor proteins.

Able to bind cis-acting elements in DNA May bind an inducer molecule that changes its conformation Mutant superrepressor proteins inhibit transcription without binding inducer Are trans-acting proteins Regulate catabolic pathways only

Currently the two main vectors for delivery of therapeutic genes for human gene therapy are

AAV and retroviruses

What are characteristics of the pedigrees of families with mitochondrial diseases?

All children of affected mothers are usually affected regardless of their sex.

What results would you expect if mitochondria are inherited uniparentally from the a strain? (required info: Researchers combined two yeast strains of opposite mating type; the a strain was resistant to chloramphenicol and the α strain was sensitive to chloramphenicol. The diploid progeny were allowed to undergo several cell divisions, and then the cells were replica plated on glycerol medium with and without chloramphenicol)

All of the yeast colonies on the plate without chloramphenicol will also grow on the plate with chloramphenicol.

A researcher planned to duplicate the Luria Delbruck fluctuation experiment. This researcher inoculated twenty samples of liquid nutrient media with bacteria from the same colony and let them grow overnight. The next morning the researcher noticed that all but one of the flasks had come open and were ruined. Not wishing to redo the experiment, the researcher spread samples of bacteria from the one intact liquid culture on twenty petri plates that had nutrient agar infused with bacteriophage. What results do you expect the researcher obtained from this experiment?

All plates had a similar number of bacterial colonies.

In a cross between an ovum from a solid green branch and pollen from a solid white branch, which phenotypes are possible in the progeny?

All progeny will be green.

Why are organisms with an odd number of chromosome sets usually sterile?

Almost all gametes will have an unbalanced set of chromosomes.

Which statement is true about sex determination in Drosophila?

Alternative splicing of Sxl transcripts in females results in an active protein that directs alternative splicing of tra transcripts in females.

The episome in an Hfr strain is inserted near the trp (tryptophan operon) locus. This Hfr strain is grown with an F- Trp- strain. From this mating, we isolate an F+ Trp+ strain that can readily impart the Trp+ phenotype to F- Trp- strains, but no other traits are ever transferred. (When the original Hfr strain is mated with F− strains, traits other than Trp+ can be transferred, although at lower frequency than Trp+.) What most likely has happened?

An F′ trp+ plasmid has been generated.

Which statement describes regulation by transcriptional repression?

An amino acid binds a repressor so that the repressor binds to the operator and prevents transcription.

oncogene/proto-oncogene

An oncogene is a cancer-inducing, gain-of-function mutant in a proto-oncogene, which is a normal gene whose product promotes cell cycle progression.

Which statement about SNPs in the human genome is true?

Any two human genome copies will have on average 3 million single nucleotide polymorphisms.

19. Replacing an adenine nucleotide with a guanine is an example of a: A) translocation. B) transition. C) transversion. D) forward mutation. E) reversion or reverse mutation.

28. In the Luria-Delbruck fluctuation experiment, the bacteria + phage plates showed: A) all plates had some resistant colonies, some had very many. B) some plates had no resistant colonies, a few plates had very many resistant colonies. C) all plates had the same number of resistant colonies. D) some plates had no resistant colonies, the plates that had resistant colonies all had the same number of resistant colonies. E) phage caused mutations to occur in some of the plates but not in others.

30. 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: A) the polymerase is more careful in replicating regions where genes exist. B) repair mechanisms correct errors made by the polymerase. C) not all mutations can be detected easily. D) the DNA polymerase has no proofreading function. E) mutations do not occur if mutagens are not present.

31. Excision repair corrects DNA by: A) removing a double-stranded fragment of damaged DNA. B) detecting, removing, and replacing a single stranded fragment of damaged DNA. C) excising the incorrect base from a nucleotide. D) removing extraneous groups such as methyl or oxygen added by mutagens. E) correcting A=T to C=G transitions.

49. The Ames test for mutagenicity is useful to identify potential carcinogens because: A) since bacteria do not get cancer they can survive lethal carcinogens. B) mutagens that affect bacterial DNA are likely to cause human mutation. C) bacteria thrive on substances that could cause cancer in humans. D) the same genes that cause cancer in humans can be mutated in bacteria. E) liver enzymes alter the bacteria so they will behave like mammal cells.

58. Shown below are the deletion maps of a series of rII- mutations. The deleted region is indicated as (......) and the intact region as ______. 1 ___________(...........)_______________ 2 _________________(...........)_________ 3 (.....................)_______________ ______ 4 ________________________(................) 5 _____(..........)______________________ A series of point mutations A-E is used in a coinfection experiment. Shown below are the results of those coinfections. Ability to produce wild-type progeny phage is indicated by (+), (o) indicates no wild type progeny. 1 2 3 4 5 A + o + + + B o + + + + C + + + o + D + + o + + E + + o + o Indicate the order that is most consistent with these data. A) CADBE B) DEBAC C) BADCE D) ABDEC E) CEADB

74. 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 carboxylic acid group. D) Two amino acids joined together is termed a dipeptide. E) All the above statements are correct.

80. The structure of a polypeptide that is characterized by a three dimensional shape with a characteristic geometry at local regions maintained by hydrogen bonds is: A) primary structure. B) secondary structure. C) tertiary structure. D) quaternary structure. E) both tertiary and quaternary structure.

81. The structure of a protein that involves the interaction between two distinct polypeptide chains is: A) primary structure. B) secondary structure. C) tertiary structure. D) quaternary structure. E) both primary and secondary structure.

86. The photoreceptor protein rhodopsin: A) is found in cone cells and is sensitive to weak light at many wavelengths. B) is found in rod cells and is sensitive to weak light at many wavelengths. C) is found in cone cells and is responsible for blue and green color vision. D) is found in rod cells and is responsible for blue and green color vision. E) is missing in individuals who exhibit red-green colorblindness.

Assume four strains (A-D) of pure-breeding stippled lettuce have been isolated. Given the results of the following crosses: A X C = stippled A X B = wild type A X D = wild type B X C = wild type B X D = stippled C X D = wild type What are the complementation groups for genes A-D? A) A,B and D,C B) A,C and B, D C) A,D and C,B D) A,B,C and D E) A,C,D and B

Mutations that reduce the function encoded by the wild-type allele are known as ________, while mutations that eliminate all function are known as ________: A) null mutations; neomorphic mutations B) hypomorphic mutations; null mutations C) hypermorphic mutations; hypomorphic mutations D) conditional mutations; null mutations E) neomorphic mutations; null mutations

The hydrolysis of an -NH2 group from a base is called ________, while intercalating agents such as acridine orange function as mutagens by causing ________: A) deamination; transversions B) deamination; deletions or insertions C) excision repair; deletions or insertions D) excision repair; transversions E) deletion; transitions

Genes A, B, C, and D are located on the same chromosome. The recombination frequencies (rf) are as follows: Relationship rf B - D 14% C - D 12% A - D 6% B - C 2% A - B 8% What is the order of the genes on the chromosome?

BCAD

Davis

Bacteria separated by filter do not alter phenotypes Phenotypes not altered by media transfer Filter with bigger pores could have changed results

Tumors that acquire the ability to break thorough _____ ______ can become metastatic

Basement membrane

How did Genentech obtain a gene for human insulin?

Because the amino acid sequence for insulin was known at the time, they designed and synthesized a human insulin gene using a nucleotide sequence based on codons that would produce the amino acid sequence.

Angiogenesis is the process of developing new _______ _______

Blood vessels

The first recombinant organism was produced by ___ in ___.

Boyer and Cohen; 1973

18. Replacing a thymine nucleotide with a guanine is an example of a: A) translocation. B) transition. C) transversion. D) forward mutation. E) reversion or reverse mutation.

22. Indicate the statement that is most accurate regarding mutations. A) Most mutations alter protein structure and phenotype. B) Only those mutations that alter protein structure will alter phenotype. C) Mutations altering a region that does not code for a protein may alter phenotype. D) All mutations that alter protein structure will alter phenotype. E) All altered phenotypes result from altered proteins.

25. 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. A) 510-6 B) 5010-6 C) 210-6 D) 210-5 E) 510-5

35. The bacterial repair system that corrects mismatched bases after polymerization is able to discriminate between the old and newly made DNA strands because: A) the new strand will contain the incorrect base if a mismatch occurs. B) older DNA is more likely to contain errors. C) older DNA contains methyl groups at specific sequences. D) newer DNA contains methyl groups at specific sequences. E) the DNA polymerase is attached to the new strand.

36. The consequence to a bacterial cell of a mutation that inactivated the enzyme that methylates the A of the sequence GATC in newly made DNA would be: A) failure to carry out replication. B) failure to correct thymine dimers. C) failure to distinguish old and new DNA during mismatch repair. D) inactivation of certain metabolic genes. E) decrease in the mutation rate.

43. Base analogs differ from other classes of mutagen in that they: A) only alter bases. B) can only cause transversions. C) only work during DNA replication or repair. D) can only cause forward mutations, nor reversions. E) will not function in bacterial cells.

48. 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 enzymes 3 sweetener 6 sweetener + rat liver enzymes 65 What conclusion is most consistent with this data? A) The sweetener is not mutagenic. B) Rat liver enzymes are highly mutagenic. C) The sweetener is not mutagenic but can be converted into strong mutagens. D) The sweetener is mutagenic and can be converted into strong mutagens. E) The sweetener and its conversion products are equally mutagenic.

51. A complementation group is: A) a group of mutations that produce the same phenotype. B) a group of mutations that are in the same gene and complement each other. C) a group of mutations that are in the same gene and do not complement each other. D) a group of mutations in two different genes that complement each other. E) a group of mutations in two different genes that do not complement each other.

55. Shown below are the results of a series of coinfections using T4 rII- strains similar to those employed by Benzer. Each strain contains a different deletion mutation. Ability to produce wild-type progeny phage is indicated by (+), (o) indicates no wild-type progeny. A B C D E A o o + o + B o o + o + C + + o o o D o + o o + E + + o + o Indicate the order that is most consistent with these data. A) CADBE B) ACBDE C) BADCE D) BEDCA E) CEADB

56. Choose the statement that best distinguishes a complementation test and a recombination analysis when examining mutations in phage. A) Both tests require two different mutations. B) Recombination can only occur between two genes. C) Complementation results can be seen immediately, recombination requires a second infection. D) Recombination results can be seen immediately, complementation requires a second infection. E) Recombination can distinguish one gene with two alleles from two different genes.

61. How many progeny phage are released when a single E. coli cell is lysed by phage T4? A) between 1 and 10 B) between 10 and 100 C) between 100 and 1,000 D) about 10,000 E) about 100,000

62. Indicate which of the following is least important in doing a complementation test with coinfection of phage T4. A) Ensuring that sufficient phage of both strains are present. B) Recovering phage from the plaques after growth and lysis. C) Counting the plaques that are produced on E. coli K(). D) Control using both mutations in cis configuration and a wild type. E) All the above steps are essential for the experiment.

63. Assume that a researcher is studying coat color in voles. Three strains of white vole have 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 blanc = all white progeny milky weiss = all brown (wild-type vole color) blanc weiss = all brown (wild-type vole color) The conclusion most consistent with these results is: A) all three strains have mutations in the same gene. B) all three strains have mutations in different genes. C) milky and blanc have mutations on the same gene, weiss has a mutation in a different gene. D) milky and weiss have mutations on the same gene, blanc has a mutation in a different gene. E) weiss and blanc have mutations on the same gene, milky has a mutation in a different gene.

66. 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 will restore the normal phenotype. C) If an enzyme in a pathway is inactive, adding excessive amounts of its product will restore the normal phenotype. D) If the enzyme that catalyzes the final step in a pathway is inactive all the other enzymes will be inactivated as well. E) If the first enzyme in a pathway is inactivated, adding the final product will not restore the normal phenotype.

67. Assume 7 different strains of fly have been isolated, each shows a recessive white eye trait. Crosses are performed as follows; (w) indicates white-eyed progeny, (R) indicates wild-type red eyes. Based on these crosses, how many different genes are present? A) only one gene with several different alleles B) 2 C) 3 D) 4 E) 7

75. Choose the condition below that does not involve a defect in an enzyme pathway. A) alkaptonuria B) albinism C) sickle-cell anemia D) phenylketonuria (PKU) E) all of the above involve a defect in an enzyme pathway

77. The condition sickle-cell anemia is due to: A) the insertion of an amino acid. B) the deletion of an amino acid. C) substitution of an amino acid. D) failure to synthesize a hemoglobin molecule. E) unequal recombination resulting in the deletion of the -chain hemoglobin gene.

84. A neomorphic mutation results in an allele that: A) produces no gene product. B) produces a nonfunctional gene product. C) produces novel proteins or cause inappropriate expression resulting in a new phenotype. D) produces proteins that aggregate with wild-type subunits, inactivating them. E) produces an altered protein that results in a wild-type phenotype.

Assume that for a given gene a mutation creates an allele that functions as a partially dominant negative as follows. The gene codes for a protein that forms a dimer within the cell. If one of the subunits has the mutant structure, the entire protein is 25% active. If both subunits are mutant, the enzyme is inactive. For a heterozygous individual, what percent of the normal activity is present in cells? A) 12.5% B) 25% C) 37.5% D) 50% E) 75%

Consider the pathway for the synthesis of the amino acid arginine in Neurospora: ARG-F ARG-G ARG-H ornithine → citrulline → succinate → arginine e e Mutant strains of Neurospora are grown in minimal media with supplements as follows. Each mutant strain carries only a single mutation. Growth is shown by (+), no growth is shown by (0). -------------------------------------------------------------------------------- Supplements -------------------------------------------------------------------------------- mutant strain nothing ornithine citrulline succinate arginine -------------------------------------------------------------------------------- a 0 0 0 0 + b 0 0 0 + + c 0 0 + + + -------------------------------------------------------------------------------- Indicate the correct strain / defective gene pairing. A) strain a / ARG-G B) strain a / ARG-F C) strain b / ARG-G D) strain c / ARG-H E) strain c / ARG-G

A bacteriophage infects a bacterial cell that has a set of genes A, B, C, D, and E in that order along its chromosome. The phage genome integrates between genes C and D. Which genes are most likely to be transduced by specialized transduction?

C and D

Genes A, B, C, and D are located on the same chromosome. The recombination frequencies (rf) are as follows: Relationship rf A - B 10% A - C 25% A - D 23% B - C 15% C - D 48% What is the most likely order of the genes on the chromosome?

CBAD

F minus strain

Cell does not have F plasmid Cell may be converted to F pilus

F plus strain

Cell has F plasmid not integrated

What is one experimental result that supports the hypothesis that cancers are clonal?

Cells from cancers of women have the same X chromosome inactivated.

Whether a bacterial colony seen in a culture plate is large or small, shiny or dull, round or irregular.

Colony morphology mutations

What are the three ways that bacteria can naturally transfer genetic material?

Conjugation, transformation, transduction

Most normal cells stop dividing when they are in contact with another cell, called _________ ___________

Contact inhibition

The enzymatic activity of CDKs are regulated by their forming a complex with which proteins?

Cyclins

16. The term mutation refers to: A) only changes in the DNA that result in new phenotypes. B) only changes in the DNA that result in novel proteins. C) any change in the DNA of a cell. D) a heritable change in the DNA of a cell. E) any change in the cell that changes its survival chances.

20. Assume that a wild-type sequence is 5'AGCCTAC3'. Indicate the sequence that might be produced by a transversion. A) 5'AGTCTAC3' B) 5'AGCCGCCGCCGCCTAC3' C) 5'AGCCCAC3' D) 5'ATCCTAC3' E) 5'AGCCTGC3'

23. Assume that the mutation rate for a given gene is 510-6 mutations per gene per generation. For that gene how many mutations would be expected if 10 million sperm are examined? A) none B) 510-6 C) 5 D) 50 E) 500

26. 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 the flasks had come open and were ruined. Not wishing to redo the experiment the researcher took bacteria samples from the one remaining intact flask and placed them on twenty phage plates. What results would you expect to see when the twenty phage plates are examined, and how would these results compare with those of the original Luria-Delbruck fluctuation experiment? A) Identical to the Luria-Delbruck results, namely different numbers of resistant colonies. B) Identical to the Luria-Delbruck results, namely identical numbers of resistant colonies. C) Not like the Luria-Delbruck results, namely different numbers of resistant colonies. D) Not like the Luria-Delbruck results, namely identical numbers of resistant colonies. E) Identical to the Luria-Delbruck results, namely no resistant colonies.

27. The results of the Luria-Delbruck fluctuation experiment indicated that: A) bacteria are naturally resistant to phage. B) a low level of any bacteria population are naturally resistant to phage. C) bacteria become resistant to phage by mutation when exposed to phage. D) bacteria become resistant to phage by random spontaneous mutation. E) the phage mutate to produce large plaques with sharp edges.

33. UV light is a mutagen that can cause: A) depurination. B) deamination. C) alkylation. D) thymine dimers. E) oxidation.

40. The duplication of the triplet sequence CGG resulting in elongation or breakage of the X chromosome is termed: A) Barr-eyed. B) Huntington's disease. C) unequal crossing over. D) fragile X syndrome. E) Rhys syndrome.

45. Alkylating agents such as ethylmethane sulfate (EMS) function as mutagens to: A) promote deletions and insertions. B) remove amine groups. C) add oxygen free radicals to bases. D) add ethyl or methyl groups. E) fit between stacked bases and disrupt replication.

47. In the Ames test for mutagenicity, rat liver enzymes are included with the compound under test because: A) bacterial cell walls must be treated to permit uptake of the compounds. B) rat liver enzymes increase the sensitivity of the bacteria to mutagens. C) rat liver enzymes kill mutant cells and allow colonies to form. D) rat liver enzymes may modify or break down some compounds. E) the mutant strain of bacteria requires rat liver enzymes to digest nutrients for growth.

50. The size of the human genome in base-pairs is about: A) 210 million B) 100,000 C) 2.75 106 D) 2.75 109 E) 2.75 1010

52. Choose the statement that is most correct regarding the rII- strain of T4 that Benzer studied. A) Produces smaller plaques than wild type. B) Produces smaller plaques, grows in E. coli K(), not in E. coli B. C) Produces larger plaques, grows in E. coli K(), not in E. coli B. D) Produces larger plaques, grows in E. coli B, not in E. coli K(). E) Produces larger plaques, grows in both E. coli K() and in E. coli B.

57. Shown below are the deletion maps of a series of rII- mutations. The deleted region is indicated as (......) and the intact region as ______. 1 _____(..........)____________________ 2 _________________(..........)________ 3 (.........)__________________________ 4 ________________________(..............) 5 ___________(...........)______________ A series of point mutations A-E is used in a coinfection experiment. Shown below are the results of those coinfections. Ability to produce wild-type progeny phage is indicated by (+), (o) indicates no wild-type progeny. 1 2 3 4 5 A + + o + + B + + + + + C + + + o + D + + + + o E + o + + + Indicate the order that is most consistent with these data. A) CADBE B) ACBDE C) BADCE D) ABDEC E) CEADB

60. 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 host cell. A) 4, 2, 3, 1 B) 1, 2, 3, 4, 5 C) 5, 1, 2, 3, D) 5, 2, 3, 1 E) 4, 5, 3, 1

64. Assume a researcher is studying the rII locus of phage T4. Three rII- strains are obtained: 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 The conclusion most consistent with these data is: A) A, B, and C carry mutations in three different genes. B) A and B carry mutations in the same gene, C is on a different gene. C) A and C carry mutations in the same gene, B is on a different gene. D) B and C carry mutations in the same gene, A is on a different gene. E) A, B, and C carry mutations in the same gene.

65. 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 = no lysis In a second experiment, coinfections are performed in E. coli strain B. When progeny phage are examined for their ability to form plaques in E. coli strain K(), the following results are obtained: A B = plaques B C = plaques C D = plaques B D = no plaques The conclusion most consistent with these data is: A) A carries a mutation in one gene, B, C and D are on a different gene, C and D both carry the same mutation. B) A and B carry mutations in the same gene, C and D are on a different gene. C) A carries a mutation in one gene, B, C and D are on a different gene, B and C both carry the same mutation. D) A carries a mutation in one gene, B, C and D are on a different gene, B and D both carry the same mutation. E) A, B, C and D carry mutations in the same gene.

68. Assume 8 different strains of fly have been isolated, each shows a recessive white eye trait. Crosses are performed as follows; (w) indicates white-eyed progeny, (R) indicates wild-type red eyes. Based on these crosses, how many different genes are present and what strains have mutations in the same gene as does strain A? A) 2, B, E, and H B) 3, B and C C) 3, B, C, and H D) 3, B, E, and H E) 4, B and H

79. 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: A) the forward mutation rate to sickle-cell is much higher in those regions. B) individuals with sickle-cell anemia live longer and have more children. C) reversion from sickle-cell to wild type is prevented in some populations. D) individuals who are heterozygous for the sickle-cell allele are protected from malaria. E) only certain populations have been tested for the presence of the sickle cell allele.

88. Red-green color blindness is more common in males than females because: A) the red pigment gene is on the X chromosome, the green is on an autosome. B) the green pigment gene is on the X chromosome, the red is on an autosome. C) rhodopsin gene is on the X chromosome. D) both the red and the green pigment genes are on the X chromosome. E) both the red and the green pigment genes are on an autosome.

89. 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 natural population. How many different color phenotypes are possible with these three alleles? A) 9 B) 2 C) 4 D) 6 E) 8

92. Assume that a series of compounds has been discovered in Neurospora. Compounds A-F appear to be members of an enzyme pathway. Several mutations have been identified and strains 1-4 each contains a single mutation. Shown below are 5 possible pathways. Choose the pathway that best fits the data presented. [growth in minimal media with supplements is shown by (+), no growth is shown by (o)] media supplement strain A B C D E F 1 o o o + + + 2 o o o o + + 3 o o o o + o 4 o o + + + + A) A B C D E F B) A B C F D E C) F B C D A E D) A B C D F E E) A B F E C D

93. The term fecundity refers to: A) ability to live a long life. B) ability to survive in several different conditions. C) ability to transcribe DNA. D) ability to produce offspring. E) ability to metabolize several different sugar molecules.

A conditional bacterial mutant is unable to methylate DNA at higher temperatures. What happens when you shift bacteria to these higher temperatures? A) the new DNA strand is more likely to contain errors B) the older DNA strand is more likely to contain errors C) the rate of mutation goes up D) a and c E) b and c

A stock of T4 phage is diluted by a factor of 10-7 and 0.1 ml of it is mixed with 0.1 ml of 108 E. coli/ml and 2.5 ml melted agar, and poured on the surface of an agar petri dish. The next day, 100 plaques are visible. What is the concentration (in plaque-forming units/ml) of T4 phages in the original T4 stock? A) 107 pfu (plaque-forming units)/ml B) 108 pfu/ml C) 109 pfu/ml D) 1010 pfu/ml E) 1011 pfu/ml

An amino acid substitution in a protein can have: A) a large effect on protein structure B) a small effect on protein structure C) little to no effect on protein structure D) all of the above E) none of the above

An observable phenotype may arise from a change in: A) the amino acid sequence B) the control of protein expression C) the amino acid sequence of an interacting subunit D) all of the above E) a and c

Assume 8 different strains of mouse have been isolated, each showing a recessive tail phenotype. Crosses are performed as follows; (+) indicates wild type, (0) indicates the behavioral trait. A B C D E F G H A 0 0 + + + + + + B 0 + + + + + + C 0 + 0 + 0 + D 0 + + + + E 0 + 0 + F 0 + + G 0 + H 0 Based on these crosses, how many different genes are present? A) 1 B) 3 C) 4 D) 5 E) 8

Assume that a new antidepressant is developed. The structure is novel and is tested using the Ames test for mutagenicity. The following results are obtained: -------------------------------------------------------------------------------- Sample Number of his+ revertant colonies -------------------------------------------------------------------------------- distilled water 2 distilled water + rat liver enzymes 3 antidepressant 37 antidepressant + rat liver enzymes 39 -------------------------------------------------------------------------------- What conclusion is most consistent with these data? A) the drug and its conversion products are not mutagenic. B) rat liver enzymes are mutagenic. C) the drug is not mutagenic but can be converted into strong mutagens. D) the drug is mutagenic and can be converted into strong mutagens. E) the drug and its conversion products are equally mutagenic.

Mutations that are in the same gene and do not complement each other are: A) a complementation group B) alleles C) deletions D) a and b E) none of the above

What is the principal determinant of overall protein structure? A) the carboxyl group. B) the amino group C) peptide bonds D) amino acid sequence E) none of the above

Which type of mutation is most likely to revert? A) deletion B) translocation C) inversion D) transposition E) transition

Genes A, B, C, and D are located on the same chromosome. The distances between the genes are below. What is the most likely order of the genes on the chromosome? Relationship Map Unit Distance A - D 18 A - B 10 B - D 8 A - C 2 D - C 20

DBAC

Histones and DNA have a strong attraction for each other because

DNA is negatively charged and histones are positively charged

Semiconservative replication of DNA means that

DNA is negatively charged and histones are positively charged.

Transduction

DNA is transferred by a virus Limit of mapping is about 2.5 minutes

Conjugation

DNA is transferred by physical interaction bacteria Transferred of DNA uses F pilus Genes mapped by disruptive mating

With respect to DNA structure, polarity means that

DNA strands have a 5′ direction and a 3′ direction.

What is a segment of DNA that can use transposase to move from one place in the genome to another called?

DNA transposon

An XY embryo may develop as female if:

During sperm formation in the embryo's father, the SRY gene was lost from the Y chromosome during crossing over in the father

17. A heritable change in DNA base sequence is called a: A) forward mutation. B) reversion. C) substitution. D) deletion. E) mutation.

32. Thymine dimers are caused by: A) X-rays. B) free radicals such as oxygen. C) EMS or NSG. D) depurination. E) UV light.

37. Unequal crossing over results in: A) an exchange between nonhomologous chromosomes. B) a loss of genetic material. C) a repair of UV-induced damage. D) a production of eggs containing Y chromosomes. E) a creation of deletions and duplications.

38. The heritable disorder fragile X syndrome, a major cause of mental retardation, is caused by: A) production of enzymes that break the phosphate backbone. B) UV light. C) X-rays. D) presence of an extra X chromosome in the sperm or egg. E) duplication of multiple three-nucleotide repeats.

39. If a man shows the premutation allele for fragile X syndrome, what is the probability that he will pass it on to his son? A) 100% B) 75% C) 50% D) 25% E) 0%

42. 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)? A) one generation B) two generations C) three generations D) at lease two, but perhaps more due to chance E) it will not occur

44. Intercalating agents such as acridine orange function as mutagens to: A) promote transitions. B) remove amine groups. C) attach to purines causing distortions. D) add ethyl or methyl groups. E) fit between stacked bases and disrupt replication.

53. A plaque is: A) a colony of bacteria growing on a plate. B) a colony of bacteria that contain phage within them. C) a region on a plate where living bacteria survive phage infection. D) an area on a plate containing live phage-resistant bacteria. E) an area on a plate containing phage and dead or destroyed bacteria.

69. In the human genetic disorder alkaptonuria, urine turns black because of the presence of homogentisic acid in individuals with the trait. This is due to: A) the presence of large amounts of homogentisic acid in the diet. B) failure of individuals with alkaptonuria to manufacture enzymes involved in the synthesis of homogentisic acid. C) failure of wild-type individuals to manufacture enzymes involved in the synthesis of homogentisic acid. D) failure of the kidneys to remove homogentisic acid from the urine. E) failure of individuals with alkaptonuria to manufacture enzymes involved in the breakdown of homogentisic acid.

72. Consider the pathway for the synthesis of the amino acid arginine in Neurospora: ARG-E ARG-F ARG-H ornithine citrulline argininosuccinate arginine Mutant strains of Neurospora are grown in minimal media supplements as follows. The strains may carry more than one mutation. Growth is shown by (+) no growth is shown by (o). Supplements mutant nothing ornitihine citrulline arginino- arginine strain succinate a o o o + + b o o o + + Strain (a) accumulates citrulline, strain b does not. Indicate the statement that is most correct regarding these two strains. A) Strain a has a mutation in ARG-E only. B) Strain b has only one mutation. C) Strain a has mutations in ARG-F and ARG-H. D) Strain a has mutations in ARG-E, ARG-F and ARG-H. E) Strain a has a mutation in ARG-H only.

73. Indicate 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 terminus contains a free amino group. E) All the above statements are correct.

76. Choose the interaction listed below that is not involved in maintaining tertiary structure in protein molecules. A) covalent bond B) hydrogen bond C) hydrophobic/hydrophilic interactions D) ionic interactions E) all of the above may be involved in maintaining protein tertiary structure

82. Assume that a certain strain of bacteria carries a mutation that causes it to die at high temperature (37C), but grows normally at cooler temperatures. This mutation is termed: A) recessive. B) deletion. C) biochemical pathway mutant. D) conditional lethal that grows under restrictive conditions. E) conditional lethal that dies under restrictive conditions.

85. 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? A) primary structure B) secondary structure C) tertiary structure D) quaternary structure E) all levels might be affected by a single amino acid substitution

90. 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. B) change in the amount of protein expressed. C) alteration in a gene that codes for a nontranslated RNA. D) change in the developmental time or location at which a gene is expressed. E) all of the above are possible consequences of a single base pair substitution.

91. Assume that a series of compounds has been discovered in Neurospora. Compounds A-F appear to be members of an enzyme pathway. Several mutations have been identified and strains 1-4 each contain a single mutation. Shown below are 5 possible pathways. Choose the pathway that best fits the data presented. [growth in minimal media with supplements is shown by (+), no growth is shown by (o)] media supplement strain A B C D E F 1 o o o + o o 2 o o o o o + 3 o o o o + + 4 o o + o o o A) A B C D E F B) A B C F E D C) A B C D E F D) A B C D E F E) A B C D E F

94. 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. For a heterozygous individual, what percent of the trimers present in the cell will be inactive? A) 100% B) 25% C) 50% D) 6.25% E) 12.5%

95. A neomorphic dominant mutation in the Antennapedia (Antp) gene of Drosophila causes: A) kinks to form in their tails. B) shortened tails. C) total loss of color vision. D) failure to assemble microtubules during mitosis. E) growth of leg from the head region.

Duplication of multiple three-nucleotide repeats is responsible for: A) sickle-cell anemia B) xeroderma pigmentosum C) alkaptonuria D) trisomy 21 E) fragile X syndrome

S. aureus is thought to possibly have acquired resistance to methicillin by incorporating a piece of DNA from _____.

Enterococcous faecalis

Certain steroids, peptides, and proteins that can acts at a distance are known as

Extracellular signals

Consider a normal chromosome with the following gene sequence along its length: F G H I J K L. Which of the following sequences represents an inversion?

F K J I H G L

Fruit flies normally have red eyes. Seven different true-breeding strains of fly with white eyes have been identified (A-G). In each strain, the white eye trait is due to an autosomal recessive allele. it is possible all seven strains have mutations in different genes. To determine how many genes are involved in eye color in these flies, pair-wise crosses are performed between each strain. The offspring phenotypes resulting from each cross are observed. (+=wild-type; - = mutant) A B C D E F G A - - + + - + + B - + + - + + C - - + + + D - + + + E - + + F - - G - Which strains' mutations represent a complementation group?

F and G

An Hfr strain is created when an___ is integrated into the host chromosome

F episome

Transfer of DNA from an Hfr cell only occurs into a ___ cell

F minus

Hfr strain

F plasmid integrated into host chromosome DNA may be transferred to recipient Could transferred whole donor chromosome

Contains an extra chromosomal F plasmid that carries some E. coli chromosomal genes.

requires virus

Contains an extra chromosomal F plasmid that codes for proteins needed to make a sex pilus

F+

Daughter cells produced in meiosis are identical.

False

The amino acid sequence of insulin was determined by ___ in ___.

Fred Sanger; 1951

In its active form, the RAS protein is associated with

GTP

In its active form, the RAS protein is associated with

GTP.

Porto-oncogene

Gain of function mutant alleles act dominantly and contribute to cancer

Vertical Transfer

Genes are passed onto organisms that are offspring Process that can be used by bacteria Sexual reproduction Mitosis

Horizontal Transfer

Genes are passes onto non-offspring organisms Process that can be used by bacteria Conjugation Transformation Transduction

What is the most significant advantage of using RNAi to study development?

Genetic studies of a single gene can be completed without creating new mutant organisms.

Contains an F plasmid that is integrated into the E. coli chromosome.

Hfr

requires cell to cell contact

Hfr

Which of the following is unlikely to be responsible for the problem of "missing heritability" in genome-wide association studies?

High levels of linkage disequilibrium between molecular markers and causal variants.

Select the order in which the following steps should be performed to express a eukaryotic protein in bacterial cells.

Identify a cDNA clone of the gene that encodes the protein Insert the cDNA downstream of the lac control region in a plasmid. Transform bacterial cells with the plasmid. Grow the bacterial cells to high density. Add allolactose to the media. Break open the bacterial cells and purify the eukaryotic protein.

loss-of-heterozygosity (LOH)

If a cell is heterozygous for a loss-of-function mutation in a tumor-suppressor gene, then one allele of the gene provides wild-type function while the other allele is nonfunctional. Any event that removes or inactivates the remaining wild-type allele results in a loss-of-heterozygosity. The cell is left with no functional copies of the tumor-suppressor gene, and this can contribute to cancer.

Which is a true statement about mitochondrial genomes?

In most cases, the mitochondrial genome is transmitted, largely intact, from one parent to offspring.

What is a reason that aneuploidy in sex chromosomes is generally better tolerated than aneuploidy in autosomal chromosomes in humans?

In somatic cells, most of the genes on only one X chromosome are transcriptionally active.

In retinoblastoma, E2F cannot be ____________ in cells in which both copied of RB have been mutated or deleted

Inhibited

Penicillin stops bacterial cell wall formation by

Inhibition of a transpeptidase

When two strains both have different mutations in the same gene but occasionally produce wild type progeny, This is due to...

Intragenic recombination

Which step in producing ATP is correctly paired with the location where it occurs?

Krebs cycle - mitochondrial matrix

The cross L p q / l P Q × l p q / l p q is carried out. If the L gene is in the middle, between genes P and Q, what would be the genotypes of the double crossover gametes in this cross?

L P Q and l p q

Tumor-suppressor gene

Loss of function mutant allele act recessively and contribute to cancer

When a phage causes a bacterial cell to make and assemble many copies of a phage. The bacterial cell then lyses, releasing the phage.

Lytic Cycle

What would be the most likely result if a scientist removes mitochondria from a human cell and attempts to grow them in culture?

Mitochondria require the products of nuclear genes to function, so the mitochondria will die soon after being removed from the cell.

Which is true about mitochondria?

Mitochondrial genomes vary in length from 6 kb to 2400 kb.

autocrine stimulation

Most normal cells will not proliferate unless they receive the proper molecular signals from their environment. Cells that exhibit autocrine stimulation can instead divide in the absence of these external signals (that is, the tumor cells provide their own division-stimulating signals).

senescence versus immortality

Most normal somatic cells undergo senescence - an end to proliferation - after they have undergone a limited number of cell divisions. In contrast, many cancer cells continue to proliferate with no such limitation - they are immortalized. An important facet of immortalized cells is that they express the enzyme telomerase, whereas most normal somatic cells lack telomerase so their chromosomes lose DNA from the telomeres during each round of cell division

What evidence supports the hypothesis that humans originated in Africa?

Mt sequence variation is highest in African populations.

Cancer genes are actually _____ _______ of normal genes

Mutant alleles

A loss-of-function mutant allele that acts recessively in cancer development is a __________ _________-____________ _____

Mutant tumor-suppressor gene

Transformation

Naked DNA is taken up by bacteria Major Mode of transferred between different species in gut

Fruit flies normally have red eyes. Seven different true-breeding strains of fly with white eyes have been identified (A-G). In each strain, the white eye trait is due to an autosomal recessive allele. it is possible all seven strains have mutations in different genes. To determine how many genes are involved in eye color in these flies, pair-wise crosses are performed between each strain. The offspring phenotypes resulting from each cross are observed. (+=wild-type; - = mutant) A B C D E F G A - - + + - + + B - + + - + + C - - + + + D - + + + E - + + F - - G - Files from Strains C and D mate and produce offspring. Do the offspring have red eyes?

Which of the following is not one of the assumptions of the Hardy-Weinberg Law?

Non-random mating occurs within the population

To increase ___________ availability, some tumors secrete substances that promote angiogenesis

Nutrient

How do offspring produced by parthenogenesis and sexual reproduction differ? (Choose an answer that is true for ALL forms of parthenogenesis.)

Offspring produced by parthenogenesis obtain genes from only a mother, while those produced by sexual reproduction obtain genes from both a mother and a father.

What is a typical characteristic of bacterial chromosomes?

On average a gene occurs once in every 1000 bp.

A gain-of-function mutant allele that acts dominantly in cancer development is an _________

Oncogene

What is the term for a mutated gene that can act dominantly to predispose a cell to a cancerous phenotype?

Oncogenes

The first recombinant DNA molecule was produced by ___ in ___.

Paul Berg; 1972

Presence of gentamicin in the environment.

What is a common type of genomic change that occurs in cancer cells?

Polyploidy

While-type genes that may mutate to become oconogenes are termed ________-__________

Porto-oncogenes

Select all characteristics of proteins that are positive regulators of transcription.

Positive regulators often bind effectors before binding with DNA. Activators regulate some degradative pathways. Positive regulators help recruit RNA polymerase.

Although bacteria can be used to produce proteins for therapeutic uses, what can be a disadvantage to using a prokaryotic system?

Proteins may not be posttranslationally processed correctly.

Cycling

Proteins that combine with kinases to direct kinase activity to a particular substrate during cell cylce

Which of the following best describes translation?

RNA -> protein

an untranslated region at the 5' end of a bacterial mRNA

RNA leader sequence

a system in bacteria that uses error-prone DNA polymerases

SOS system

To increase nutrient availability, some tumors __________ substances that promote angiogenesis

Secrete

Select all the statements that correctly describe how to identify a mutant in E. coli.

Select for ampicillin resistance by growth in media containing ampicillin. Screen for tryptophan auxotrophs by replica plating colonies on media with and without tryptophan.

She may have children who are blind due to LHON, Some cells in her body are probably homoplasmic

Luria and Delbruck grew many liquid cultures of bacteria then spread a small sample of each culture on nutrient agar infused with bacteriophage in separate petri plates. They assayed the number of bacterial colonies that formed on each plate. When Luria and Delbruck assayed bacterial growth on the petri plates, what did they find?

Some plates had no bacterial colonies; others had varied numbers of colonies.

What results would you expect if mitochondria are inherited biparentally? (required info: Researchers combined two yeast strains of opposite mating type; the a strain was resistant to chloramphenicol and the α strain was sensitive to chloramphenicol. The diploid progeny were allowed to undergo several cell divisions, and then the cells were replica plated on glycerol medium with and without chloramphenicol.)

Some, but not all, yeast colonies found on the plate without chloramphenicol will also grow on the plate with chloramphenicol.

Ocogenic versions of the Ras gene produce Ras proteins that are always activated and therefore they ________ ________ ________

Stimulate cell division

a researcher is studying the all locus of phage T4. Three rll- strains are obtained: A,B, and C. E. coli strain K is coinfected with two rll- strains simultaneously and the results are recorded. Infection with A and B phage= plaques form Infection with A and C phage= plaques form Infection with B and C phage= no plaques form What can be inferred from this complementation test?

Strains B and C have mutations in the same gene, and Strain A has a mutation in a different gene

A researcher is studying the rII locus of phage T4. Three rII− strains are obtained: A, B, and C. E. coli strain K(λ) is coinfected with two rII− strains simultaneously and the results are recorded. Infection with A and B phage = plaques form Infection with A and C phage = plaques form Infection with B and C phage = no plaques form What can be inferred from this complementation test?

Strains B and C have mutations in the same gene, and strain A has a mutation in a different gene.

Fruit flies normally have red eyes. Seven different true-breeding strains of fly with white eyes have been identified (A-G). In each strain, the white eye trait is due to an autosomal recessive allele. it is possible all seven strains have mutations in different genes. To determine how many genes are involved in eye color in these flies, pair-wise crosses are performed between each strain. The offspring phenotypes resulting from each cross are observed. (+=wild-type; - = mutant) A B C D E F G A - - + + - + + B - + + - + + C - - + + + D - + + + E - + + F - - G - What can you infer about the locations of the mutations in strains C and D?

Strains C and D have mutations in the same gene

In forensics, a DNA sample is analyzed to determine which alleles of 13 SSR loci are present. How is the probability of that specific combination of SSR alleles existing in the population calculated?

The Hardy-Weinberg Law is used to predict the genotype frequency at each locus.

What did comparing the sequence of the mitochondrial genome in trypanosomes with the sequence of mature mitochondrial RNAs demonstrate?

The RNA sequences are similar to the genome sequence, but have insertions and deletions of uracil residues.

Why is the number of X chromosomes crucial for sex determination in Drosophila?

The Sxl promoter is responsive to the concentration of four transcription factors produced from genes on the X chromosomes.

In four o'clock plants, reciprocal crosses are performed with a green plant and a white plant. How will the offspring of the reciprocal crosses look?

The offspring will be white if the egg cam from the white plant and green if the egg came from the green plant.

In four o'clock plants, reciprocal crosses are performed with a green plant and a white plant. How will the offspring of the reciprocal crosses look?

The offspring will be white if the egg came from the white plant and green if the egg came from the green plant.

If hundreds of progeny from a cross are all white, what can be concluded about the parent plants?

The ova had to come from a branch that was solid white. The pollen could have come from a branch that was solid white, solid green, or variegated.

If a cross produces hundreds of progeny that are a mixture of white, green and variegated, what can be concluded about the parent plants?

The ova had to come from a branch that was variegated. The pollen could have come from a branch that was solid white, solid green, or variegated.

Which statement describes evidence in support of the endosymbiont theory?

The sequence of mitochondrial rRNA genes are most similar to the rRNA genes in purple bacteria.

What would you anticipate would be true about the metabolism of a bacterial species isolated from water samples, one at the surface and another from a hot vent on the ocean floor?

The species from the water surface would be more likely to be able to conduct photosynthesis.

Which statement best describes the action of polypeptide growth factors?

They bind to cell surface receptors and trigger intracellular signal transduction pathways.

Select all the characteristics of DNA transposons.

They can integrate into the host genome. They can move from one site in the host genome to another site. They require transposase to move and integrate. They create mutations by disrupting coding sequences. They contain inverted repeat sequences.

Why are some individuals are predisposed to getting cancer?

They inherit mutant alleles of genes that are involved in cancer development.

How does tryptophan, the end product of the trp operon, function in the regulation of the operon?

Trp binds to and changes the conformation of the repressor, which can then bind DNA and block transcription of the operon

A mutation that results in production of a mutant protein with only one amino acid change (compared to the wild-type protein) can result in a dramatic difference in phenotype.

True

The amino acid sequence of a protein determines its shape and specific function.

True

apoptosis/programmed cell death

When the genome of a normal cell becomes damaged past the point where it can be repaired, a genetically-directed program of cell death called apoptosis occurs, leading to the destruction of that cell. Cancerous cells often have lost their ability to undergo apoptosis, and this loss is dangerous because it allows cells with damaged genomes to proliferate.

What kind of information will be used for personalized cancer treatment?

Whole genome sequencing.

Three genes (X, Y, and Z) are in the same region of a bacterial chromosome. To determine the order of these genes, you infect X− Y− Z− cells with a lysate from wild-type cells infected with a generalized transducing phage. When X+ cells are selected, 70% of cells are also Y+ and 5% of cells are Z+. When Y+ cells are selected, 68% of cells are also X+ and 1% are Z+. What is the relative arrangement of the three genes?

X is in the middle, but closer to Y.

Suppose a three-point testcross was conducted involving genes X, Y, and Z. If the most abundant classes of progeny are X Y z and x y Z and the rarest classes are x Y Z and X y z, which gene is in the middle?

which of the choices give the correct sequence of early embryonic development in Drosophila?

Zygote, multinucleate syncytium, syncytial biastoderm, celluar blastoderm

inversion

a 180 degree rotation of a chromosomal segment

In transduction, the DNA is being moved between the two cells by

a bacteriophage

The current model of cancer development is that

a cancer develops from a single cell that evolves through multiple mutations.

loss-of-heterozygosity

a cell with one mutant tumor-suppressor allele acquires a second loss of function mutation in the wild type allele

cyclin-dependent protein kinases

a class of cell cycle enzymes that phosphorylate proteins

Which has been associated with aging in humans?

a decrease in mitochondrial function

A scientist might create a conditional knockout of a mouse gene when

a homozygous loss-of-function mutation in the gene causes embryonic lethality.

growth factor

a hormone or cell bound signal that stimulates or inhibits cell division upon binding a membrane receptor

The enzyme telomerase is essential for unlimited cell division since

a lack of telomerase will result in chromosome shortening and cell death.

A haploid egg formed. The chromosomes in the egg underwent DNA replication. The sister chromatids separated during anaphase of mitosis but then remained in a single cell as separate chromosomes to yield a diploid egg. Then will the offspring be homozygous or heterozygous?

a little of both

checkpoint

a molecular pathway that prevents cell cycle progression until necessary preconditions have been fulfilled. For example, the G1-to-S checkpoint prevents cells from replicating their chromosomes until any DNA damage has been repaired.

Which are typically used for positional cloning of a disease gene in humans?

a multigenerational selective breeding program

null or amorphic mutation

a mutation inside or outside a coding region that results in the complete loss of a protein's function

neomorphic

a mutation inside or outside the coding region that produces a protein that either has a new function or has a normal function but is produced at an inappropriate time

hypermorphic

a mutation inside or outside the coding region that results in increased production or activity of a protein with the same function as the wild-type protein

the episome in an Hfr strain is inserted near the trp (tryptophan) locus. This Hfr strain is incubated with an F- trp- strain. We isolate a trp+ strain that can readily donate the trp+ phenotype to other F+ trp- strains. No other traits are transferred. What has happened? a. an F+ trp plasmid has been generated b. typical Hfr mating c. transduction occurs d. Transformation occurs

a. An F+ trp plasmid has been generated

what is a difference between a Tn and IS element? a. Tn elements can carry antibiotic genes b. IS elements carry a transposase gene c. Tn elements integrate into plasmids and genomes d. IS elemetns integrate into plasmids and genomes

a. Tn elements can carry antibiotic resistance genes

after a tautomeric shift in adenine,

adenine bones with cytosine

which gene would you predict would be part of the core genome and not the pangenome? a. gene involved in glucose utilization b. antibiotic resistance gene c. metal resistance gene d. transposase

a. gene involved in glucose utilization

Penecillin stops bacterial cell wall formation by a. inhibition of a transpeptidase b. inhibiting synthesis of NAM c. inhibiting synthesis of NAG d. inhibiting transport of NAG and NAM past the permeable membrane

a. inhibiting of transpeptidase

A bacterium is found that is resistant to the antibiotic gentamicin. The bacterium was isolated in a hostpital where patients were routinely given gentamicin for a variety of infections. What was the pressure that selected for this resistant population? a. presence of gentamicin in the environment b. high mutation rate for the bacterium c. growth situation for the bacterium d. patients not receiving antibiotic provided source of bacteria

a. presence of gentamicin in the environment

Two strains of S. cerevisae (yeast) are crossed. One has the genotype ABC and the other abc. Five sets of the resultant tetrads are noted below. In which set did a gene conversion event occur?

abc, aBc, AbC, aBC

When a strain that was normally sensitive to an antibiotic becomes resistance the phenomenon is called ______

acquired antibiotic resistance

What is a trans-acting factor that increases transcription above the basal rate called?

activator

What is a transcription factor that associates with an enhancer and causes an increase in initiation of transcription?

activator

a trans-acting factor that increases transcription above the basal rate

activator

bind to enhancers

activators

Alkylating agents, such as ethylmethane sulfate (EMS), are mutagens because they

add ethyl or methyl groups to bases.

When a dideoxynucleotide is incorporated into one new strand by DNA polymerase,

addition of nucleotides only to that strand ceases.

A programmed cell change that results in cell death is referred to as

apoptosis.

A trait unique to embryonic stem cells that makes them useful for generating knockout animals is that they

are totipotent

The laboratory process by which cells can be manipulated so that they take up DNA from the environment is known as _____.

artificial transformation

Expression of homeotic genes

assigns a unique identity to each segment.

A crucial step in the regulation of most bacterial genes occurs

at transcription initiation

premature termination of transcription in response to translation of an RNA leader

attenuation

capable of taking up DNA

auxotroph

grows on minimal medium only if supplemented

auxotrophic

In the Ames test for mutagenicity, __.

auxotrophic bacteria are converted to prototrophs that survive

A strain of E. coli is trp his lac. which medium would this bacterium grow on? a. lactose+histidine+tryptophan b. glucose+histidine+tryptophan c. maltose+histidine+tryptophan d. minimal glucose, no histidine, no tryptophan e. glucose+histidine+tryptophan and maltose+histidine+tryptophan

b. glucose+histidine+tryptophan

What characteristics make bacteria E. coli attractive as model organism? a. short generation time, relatively simple, easily mutagenized, haploid, gene control mechanisms identical to eukaryotes b. short generation time, relatively simple genomes, easily mutagenized, haploid c. short generation time, relatively complex genome, easily mutagenized, haploid d. short generation time, relatively simple genome, easily mutagenized, diploid

b. short generation time, relatively simple, easily mutagenized, haploid

A plasmid that contains an open reading frame for the penecillin resitance gene flanked at the 5' end with sequences from the LacZ gene and at the 3' end with different sequences from the LacZ open reading frame. Bacteria are placed on media that contains penecillin. What is the conclusion regarding the bacteria that grow on the plate? a. the plasmid is inhibiting LacZ production b. The genome carries a mutation in the LacZ gene c. No inference can be made concerning the state of the genome LacZ gene d. The bacteria should be able to produce beta-galactosidase

b. the genome carries a mutation in the LacZ gene

bind to promoters

basal factors

If integration of DNA provided by pronuclear injection occurs after three cell divisions, the resulting mouse will

be a mosaic of cells with some cells containing the transgene and others not.

A trans-acting factor functions by

binding to enhancers or promoters leading to increased or decreased transcription.

a preferred sugar prevents transcription of a sugar-metabolizing operon

catabolite repression

how is the blue-receiving protein different from rhodopsin

blue receiving protein is expressed in cone cells and rhodopsin is expressed in rod cells blue-receiving protein is sensitive only to blue light and rhodopsin is sensitive to all visible light wavelengths mutations in the gene for blue-recieving protein often have effects that are less severe than mutations in the gene for rhodopsin

Transcription in prokaryotes and eukaryotes is similar in that

both are regulated by binding proteins to DNA near the gene being transcribed

When an F+ donor gives an F plasmid to an F- recipient

both become F+

During specialized transduction, a phage transfers ______ to a recipient bacterial cell.

both phage DNA and bacterial DNA

After exposure to Agrobacterium tumefaciens bacteria containing both a recombinant T-DNA vector and a helper plasmid, new plants can be grown from single cells in the presence of herbicide. Without the herbicide,

both transformed and nontransformed plants will grow

after exposure to Agrobacterium tumefaciens bacteria containing both a recombinant T-DNA vector and a helper plasmid, new plants can be grown from single cells in the presence of herbicide. Without the herbicide,

both transformed and nontransformed plants would grow

both transformed and nontransformed plants would grow.

What would happen if a transposon were to integrate into the origin of the bacteria genome? a. transposon would be replicated like the genome b. transposon would "jump" to another location c. transposon would inactivate the origin, no DNA replication possible d. transposon would express its genes

c. transposon would inactivate the origin, no DNA replication possible

When complexed with ________, the CRP protein binds to the CRP binding site and ________ the expression of the lac operon.

cAMP; switches on

Resistance___ be transferred between members of the same species or between different species.

can

horizontal gene transfer

can accelerate evolution of a species

In an Hfr strain, the F episome is integrated between genes A and B. When this Hfr mates with an F− strain, gene B is always transferred first to the F− cell. What is the last bacterial gene that could possibly (at least in theory) be transferred to the F− from the host chromosome?

gene A

Repair of heteroduplex regions formed during recombination can result in a 1:3 or 3:1 segregation of parental alleles, which indicates that ________ has occurred.

gene conversion

The sum total of all alleles carried in all members of a population is called its

gene pool

The sum total of all alleles carried in all members of a population is called the

gene pool

Why are conditional knockout animals desirable?

genes that are essential for development can be deleted in the adult or only in specific tissues.

What describes a situation in which an allele's expression depends on the parent from which it was inherited?

genomic imprinting

The proportion of individuals in a population that are of a particular phenotype is the

genotype frequency

The proportion of individuals in a population that are of a particular genotype is the

genotype frequency.

Transcription occurs ________ and translation occurs ________ of eukaryotic cells.

in the nucleus; in the cytoplasm

what is a property of a pathogenic bacterium? a. it may produce a protein that interferes with basic cellular functions b. there may not be a non-pathogenic strain of the species c. it probably conducts photosynthesis d. it probably fixes nitrogen

it may produce a protein that interferes with basic cellular functions

When a bacteriophage carrying bacterial DNA infects a new bacterium

it transfers bacterial DNA from the donor bacterium to the recipient bacterium.

When a bacteriophage carrying bacterial DNA infects a new bacterium,

it transfers bacterial DNA from the donor bacterium to the recipient bacterium.

The activity of Rb is regulated by

its phosphorylation state.

The Lac repressor binds to what site within the lac operon?

laco

a type of dimerization domain

leucine zipper

tumor-suppressor gene

loss of function mutant alleles act recessively and contribute to cancer

When comparing replicate populations of flutterby bushes growing on the Hogwarts' grounds or in Professor Sprout's greenhouse, the greenhouse population will likely have _____VE, _____ VP, and ___________ heritability.

lower/lower/higher

In eukaryotic cells, replication proceeds from ________ origin(s) of replication.

many

What is the order of action of these classes of genes during Drosophila development?

maternal effect, gap, pair rule, segment polarity

The leucine zipper motif functions to

mediate the physical association of two polypeptides.

The ability of a cell to move to other parts of the body is known as

metastasis

Tumors that acquire the ability to break thorough Basement membrane can become__________________

metastatic

a system in backer that uses methyl groups on the parental DNA a strand to determine which of 2 non complementary bases is correct

methyl-directed mismatch repair

Assume that a researcher is studying coat color in voles. Three strains of white vole have 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 x blanc = all white progeny milky x weiss = all brown (wild-type vole color) blanc x weiss = all brown (wild-type vole color) The conclusion most consistent with these results is

milky and blanc have mutations on the same gene, weiss has a mutation in a different gene.

A strain of E. coli is trp− his− lac−. Which medium would this bacterium grow on?

minimal medium with glucose as the sugar, supplemented with histidine and tryptophan

A strain of E. coli is trp− his− lac−. Which medium would this bacterium grow on?

minimal medium with glucose as the sugar, supplemented with histidine and tryptophan.

The DNA sequence 5′ ATGGGGGACACC 3′ encodes the amino acids Met Gly Asp Thr. A mutation changes the sequence to 5′ ATGGGGAACACC 3′ that encodes the amino acids Met Gly Asn Thr. What type of mutation has occurred?

missense mutation

no one, theyll all be different

A mutation that changes a codon that originally coded for an amino acid into a stop codon is a

nonsense mutation.

Mutations that completely abolish the function of a wild-type allele are

null mutations

A large deletion removes the promoter and first three exons of a gene. No mRNA or protein is detected. What type of allele is this mutant allele?

null/amorphic

The cellular organelle responsible for protein synthesis is the

ribosome

RNA molecules that act as enzymes to catalyze specific biochemical reactions are

ribozymes

Proofreading by DNA polymerase involves the removal of

several bases on the newly-synthesized strand of DNA

What characteristics make bacteria like E. coli attractive as model organisms?

short generation time, simple genome relative to to that of humans, easily mutagenized, haploid

in light repair,

the covalent bonds between the thymine dimers are broken

What is involved in the repair of thymine dimers

the enzyme DNA photolyase, exposure to light, and the transfer of an electron to the dimer

The heritable disorder fragile X syndrome, a major cause of intellectual disability, is caused by __.

the expansion of a region of trinucleotide repeats

cyclin-dependent kinases (CDKs)

the key enzymes that drive cell cycle progression. CDKs generally consist of two subunits: One subunit is a kinase, an enzyme that phosphorylates (adds phosphate groups to) other proteins. The other subunit is a cyclin, a polypeptide whose abundance varies with stages of the cell cycle and which functions as a spe

driver mutations

the mutations found in the genomes of the cancerous cells in the patient that are most likely to contribute to tumor formation. Other mutations in the genomes of cancer cells that are unlikely to contribute to tumor formation are often called passenger mutations. Because of genome instability, cancer cell genomes are likely to accumulate several driver mutations and many passenger mutations.

In plant cells, DNA molecules are found inside which structures?

the nucleus, the mitochondrial matrix, the choloroplast stroma

contact inhibition

the process by which normal cells stop dividing when they come into physical contact; normal cells cultured on petri plates thus proliferate until they form a monolayer one cell thick at the bottom of the plate. Cancerous cells lose contact inhibition; in culture, tumor cells form piles called transformed foci that are many cells thick.

tumor progression

the process by which pre-cancerous and cancerous cells progressively accumulate (through mutation) additional properties that make the cancers increasingly invasive and malignant.

Following conjugation of an Hfr cell with an F− cell,

the recipient remains F−.

if a frameshift mutation causes a stop codon to be inserted into the open reading frame of a gene,

the resulting protein will be shorter than normal and may be nonfunctional

sickle cell anemia is caused by what change in the hemoglobin B chain?

the substitution of one amino acid for another

Avery and colleagues purified a white substance as the transforming principle. Treating this substance with enzymes that destroyed RNA, protein, or polysaccharides did not affect its ability to transform cells, but enzyme that degrades DNA destroyed the transforming ability. These results suggested that

the transforming principle appeared to be DNA.

Transgenic animals made by pronuclear injection can be limited for studies of the links between genes and disease because

the transgene allele must be dominant to the normal, endogenous allele and some diseases are caused by recessive mutations.

Fixation

when only one allele in a population has survived and all individuals are homozygous for that allele

Which is a type of DNA-binding domain found in transcription factors?

zinc finger

a type of DNA binding domain

zinc finger

a type of DNA-binding domain found in transcription factors

zinc finger

Cancer cells

— exhibit autocrine stimulation — continue dividing when cells contact one another — do not undergo apoptosis when the DNA is damaged — have lost gap-junction connections to their neighbors

Cancer cell

— loss of inhibition — many chromosomal abnormalities — capable of dividing indefinitely — several successive mutation in a proliferative clone of cells

Normal cell

— stable genome — relatively low levels of telomerase — does not invade surrounding tissues — undergoes apoptosis following unrepaired DNA damage s

Normal Cells

— their cell division is triggered by signals from neighboring cells — exhibit contact inhibition — undergo apoptosis when DNA is too damaged — connect to their neighbors his gasp junctions

Current approaches to personalized cancer treatments

— tumor genomes are compared to those of normal cells of the Samuel individual — the same drugs may treat cancer of different tissues if the tumors share common oconogenic mutations — gene replacement is widely sued to restore tumor suppressor genes to cancer cells

Select all examples of mutations that are likely to be recessive to wild-type alleles.

- A null allele of Gene X, if Gene X is haploinsufficient. - A hypermorphic allele of Gene Z that encodes a constitutively active protein.

Which is the best method to demonstrate the function of a putative enhancer?

- Compare DNA sequences from two or more species and identify conserved regions located outside of coding regions. - Introduce two separate pieces of DNA into a eukaryotic cell; one is a fragment of DNA with the putative enhancer and the other is a plasmid that contains a reporter gene. - Clone the putative enhancer into a reporter construct and measure the level of reporter gene expression in a prokaryotic cell - Crosslink genomic DNA and associated proteins, fragment the DNA, use an antibody to isolate DNA sequences bound to a particular transcription factor, and sequence the DNA.

Which of these are required for a Sanger sequencing reaction?

- RNA polymerase - Four ribonucleotides (ATP, GTP, CTP, TTP) - Single-stranded RNA template - A random RNA primer

The R and S genes are linked and 10 map units apart. In the cross R s / r S × r s / r s what percentage of the progeny will be R s / r s?

45%

If 35% of the bases in a region of the mouse genome are cytosine, what percentage in that region are adenine?

15%

protein

- polymer of 20 different amino acids - order of monomers is important for function - can catalyze chemical reactions - has most variable chemical structure - can fold into a variety of 3D shapes

RNA

- polymer of four different nucleotides - can store, replicate, and express heritable information - order of monomers is important to function - can fold into a variety of 3D shapes - can catalyze chemical reactions

DNA

- polymer of four different nucleotides - consists of two strands facing opposite directions - has most stable chemical structure - can store, replicate, and express heritable information - order of monomers is important to function

Which process(es) can generate recombinant gametes?

- segregation of alleles in a homozygote - crossing-over between two linked homozygous loci

Hemophilia is caused by an X-linked recessive mutation in humans. If a woman whose paternal uncle (father's brother) was a hemophiliac marries a man whose brother is also a hemophiliac, what is the probability that their first child will have hemophilia? (Assume that no other cases of hemophilia and no hidden carriers exist in the pedigree.)

If a man has one premutation allele for fragile X syndrome, what is the probability that he will pass the premutation allele on to his son?

Genes A and B are on different (nonhomologous) chromosomes. If an individual's genotype is Aa Bb, what is the genotypic ratio of gametes produced?

1 A B : 1 A b : 1 a B : 1 a b

The genetic code includes

1 start codon and 3 stop codons

PCR Cycle

1. Heat denaturation of strands of target DNA 2. Hybridization of primers to target DNA 3. Addition of deoxyribonucleotides by DNA polymerase

To estimate the genome size of a newly discovered organism, you digest one copy of its genomic DNA with the restriction enzyme EcoRI, which has a 6 bp recognition site. The genome is cut into about 100,000 fragments. Which is your best estimate of the size of this organism's genome?

400 Mb

Calculate the probability of homozygous genotypes for the genes A, B, E, and F in the offspring of the cross Aa Bb cc dd Ee Ff × Aa Bb Cc dd Ee Ff.

1/128

In the dihybrid cross Aa Bb × aa bb, what proportion of heterozygotes for both gene pairs is expected among the F1 offspring?

1/4

Suppose that in plants, smooth seeds (S) is dominant to wrinkled seeds (s) and tall plants (T) is dominant to short plants (t). An F1 tall plant with smooth seeds was crossed to a parent plant that was short and wrinkled. What proportion of the progeny is expected to be heterozygous for tall and smooth?

1/4

Imagine that DNA is composed of equal proportions of six different types of nucleotide, instead of the normal four. The six nucleotides are A, C, G, T, X, and Y. In this new type of DNA molecule, A pairs with T, C pairs with G, and X pairs with Y. What would be the average size of the DNA fragments produced when this new DNA is cut by a restriction endonuclease with a four-base recognition sequence?

1296 bp

Drosophila melanogaster has four pairs of chromosomes (including a pair of sex chromosomes). Sperm from this species are formed by a meiotic process in which homologous chromosomes pair and segregate but do not undergo crossing-over. How many genetically different kinds of sperm could be produced by a Drosophila melanogaster male (XY)?

If a trait is controlled by two codominant alleles of one gene, what phenotypic ratio is expected in the offspring of a mating of two heterozygotes?

1:2:1

When DNA microarrays are used to genotype SNPs, what form of DNA is attached to the silicon chip?

20-40 base allele-specific oligonucleotides

In a certain breed of plants, dark green is determined by the dominant allele G and light green is determined by the recessive allele g. The heterozygote shows 75% penetrance for the dominant phenotype. If the parental cross is GG × gg, how many light green plants would be expected in a population of 400 F2 plants?

250 dark green; 150 light green

If an individual has 10 gene pairs, how many different gametes can be formed if three of the gene pairs are homozygous and the remaining seven gene pairs are heterozygous?

2^(number of heterozygous genes) = 128

DNA polymerases use their ________ activity to remove a mismatched base.

3' → 5' exonuclease

A disease is caused by homozygosity for the g allele (G is the corresponding wild-type allele). However, the penetrance of the disease is 75%. Two individuals known to be heterozygotes have a child. What is the probability that the child exhibits the disease?

3/16

Allele specific oligonucleotides (ASO) for the normal and disease alleles of a gene are in one section of a microarray. The disease is a recessive trait. If a probe made from an individual's genomic DNA hybridizes with both ASOs, what can be inferred about the individual?

50% of the individual's children are expected to be carriers

A tRNA with the anticodon sequence 5′ IUA 3′ will not normally exist because

5′ UAA 3′ is a stop codon.

What is a RefSeq?

A RefSeq is a single, complete, annotated version of a species' genomic DNA sequence that can be accessed for bioinformatic studies.

According to Mendel's law of equal segregation, an Aa monohybrid makes two types of gametes with equal frequency. These two gamete types are:

A and a

missense mutation

A mutation that results in production of a mutant protein with only one amino acid change (compared to the wild-type protein) can result in a dramatic difference in phenotype.

Which statement describes a primary mutant screen?

A scientist examines a large number of mutagenized zebrafish embryos for abnormalities in blood vessel formation.

transposition

A short DNA segment moves from one position in the genome to another

Which piece of evidence is most likely to indicate a gene within a genome?

A unique sequence within a genome is 80% similar in human, mouse, and zebrafish.

Which sequences are at the end of PCR amplified DNA fragments?

Deoxyribonucleotides that correspond to primer sequences

What is one way that genes can be predicted in genome sequences?

Identifying the most conserved sequences between different species.

In Sanger sequencing, what causes DNA synthesis to terminate at a specific base?

Incorporation of a dideoxynucleotide that lacks a 3′ hydroxyl.

How can microarrays differentiate between a wild-type allele and a disease allele that differ at only one nucleotide?

Oligonucleotides hybridize with the two alleles differently.

E. coli cells that are sensitive to ampicillin are mixed with many copies of a plasmid that has a gene for ampicillin resistance and then plated on medium containing ampicillin. What will happen next?

Only E. coli cells that have taken up a plasmid will grow and form colonies.

Which is part of a DNA sequencing technique that is useful for high-throughput sequencing, but is not part of Sanger DNA sequencing?

Removal of a chemical group that blocks the 3′ end of the new DNA strand

A bacterial mismatch repair system is able to correct replication errors that insert an incorrect nucleotide. How is this repair system able to determine which mismatched base is incorrect?

Some bases of the parental strand are methylated, while none of the new strand are.

How does DNA structure relate to its function?

The order of nucleotides in a DNA strand specifies the order of amino acids in a protein.

What is the purpose of ethidium bromide in DNA electrophoresis?

To tag DNA fragments so they can be viewed under UV light

Sister chromatids are linked together by their centromeres.

True

Which sex chromosome aneuploidy is not usually seen in live births?

The presence of a selectable marker on a plasmid allows the researcher to determine if

a bacterial cell has taken up the plasmid.

Which of these examples represents a gene family?

a genome includes many genes that encode myosin motor proteins.

Which is an example of a recombinant DNA molecule?

a genomic fragment of human DNA ligated into a bacterial plasmid vector

In the modification of eukaryotic mRNA, ______ cap and ______ tail are usually added to the transcript.

a methylated-guanine; a poly-adenine

The recognition site for a restriction enzyme is 5′ ACC^GGT 3′. The ^ symbol indicates the site of cleavage. After digestion of DNA with this restriction enzyme, how will the ends of the resulting DNA fragments look?

blunt ends

Huntington disease is caused by expansion of the trinucleotide repeat region of the HD gene that results in the production of a Huntingtin protein with an expanded number of glutamines. An animal model with most features of this syndrome could be created by

adding a transgene containing a disease-causing mutant allele of the HD gene to a mouse or primate genome.

cDNA is

any DNA produced using an RNA template.

A female mouse from a true-breeding wild-type strain was crossed to a male mouse with apricot eyes (ap) and grey body (gy). The F1 mice were wild-type for both traits. When the F1 were interbred, the F2 were distributed as follows: Females all wild type 200 Males wild type 91 apricot 11 grey 9 apricot, grey 89 Which of the following statements is correct?

ap and gy are X-linked and 10 map units apart

The amino acid carried by a transfer RNA is joined to the 3' end of the transfer RNA by a(n)

covalent bond

UV light damages DNA by causing

covalent bonds to form between thymine bases next to each other on the same DNA strand.

All the genes in a species' core genome are located on the bacterial chromosome, whereas the genes of the pangenome are carried on plasmids.

false

To generate a cDNA library from mouse muscle cells, reverse transcriptase is required to make

double-stranded cDNA from mature mRNA isolated from muscle cells.

What is the term for a cis-acting DNA sequence that may function at a distance from the gene they are regulating?

enhancer

A variation in gene function that does not involve a change in DNA sequence but can be inherited is a(n)

epigenetic phenomenon

If a phenotype is controlled by the genotypes at two different loci, a possible interaction between alleles of these genes can be called

epistasis

The primer used in Sanger sequencing

has a nucleotide sequence complementary to the 3' end of the template, just outside the region to be sequenced.

A researcher has a laboratory strain of flies that have loss-of-function mutations in both gene X and white. These flies are used as hosts for P element transformation: Embryos of the double mutant strain are injected with two plasmids, one containing a wild-type copy of the white gene (w+) and a wild-type copy of gene X, side-by-side within P element inverted repeats, and the other plasmid containing only the P element transposase gene. Transgenic offspring of the injected flies will

have red eyes and a wild-type copy of gene X integrated into a random location in the genome.

A codon is a three-base sequence of

mRNA that codes for an amino acid.

reciprocal translocation

non homologous chromosomes exchange parts

During mitosis, if all of the chromosomes in a diploid cell fail to separate and instead segregate into one daughter cell, the result will be what?

only one tetraploid daughter cell

What information cannot be determined from the DNA sequence of a cDNA clone?

sequence of the promoter

FISH analysis is likely to detect which type of change in DNA?

silent point mutations and frameshift mutations

What are sticky ends?

single-stranded DNA sequences that are generated by staggered cuts

In gel electrophoresis, DNA fragments move at different rates because they have different

sizes

What might be the outcome of repeated duplications of one or a few genes in a species' genome?

the presence of gene families

A researcher performs FISH with a probe against a known chromosome 3 sequence on cells with a small deletion on the p arm of chromosome 3. If two fluorescent spots are observed in each cell, what is the most likely explanation?

the sequence targeted by the probe is not within the deleted region.

Telomeres consist of direct repeat sequences.

true

To sequence DNA by Sanger sequencing, the DNA to be sequenced must first be denatured to form a single-stranded template.

true

Using PCR, over 1 × 106 copies of a DNA target can be made from one double-stranded DNA template.

true

Deletions are most useful for gene mapping

when you have a mutant allele of a gene that is recessive to normal alleles and amorphic.

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