BIOL 4003 EXAM 2 Quizzes

The ________ is the feature that allows DNA to store information

a.) spiral structure

b.) relative location of the major and minor groove

c.) base sequence

d.) 5' to 3' direction of the strands

c.) base sequence

Chargaff's results suggest that (in DNA)

a.) the amount of G=C and A=T

b.) the amount of G=A and C=T

c.) the amount of G=T and A=C

d.) all of the above

a.) the amount of G=C and A=T

Which of the following could be the components of a single nucleotide found within an RNA strand?

a.) deoxyribose, thymine, and phosphate

b.) deoxyribose, guanine, and three phosphates

c.) ribose, thymine, and phosphate

d.)ribose, uracil, and phosphate

d.)ribose, uracil, and phosphate

Which component(s) of a nucleotide is/are not found along the DNA backbone?

a.) bases

b.) deoxyribose

c.) phosphate

d.) all of the above are found in the DNA backbone

a.) bases

Which of the following proteins is/are used by a retrotransposon (retroelement), which is a transposable element that moves via an RNA intermediate?

a.) reverse transcriptase

b.) transposase

c.) intergrase

d.) both a and c

d.) both a and c

Which of the following statements regarding transposable elements is the most accurate

a.)Transposable elements are most abundant in prokaryotic genomes.

b.)Transposable elements are most abundant in the genomes of simple eukaryotic genomes, such as yeast.

c.)Transposable elements are most abundant in the genomes of complex, multicellular eukaryotes.

d.)Transposable elements are very rarely found in genomes because they are eliminated via natural selection.

c.)Transposable elements are most abundant in the genomes of complex, multicellular eukaryotes.

Which of the following is found in a eukaryotic chromosome but not in a bacterial chromosome?

a.) many genes

b.) one centromere

c.) some repetitive sequences

d.) one or more origins of replication

b.) one centromere

Let's call two different DNA molecules DNA-A and DNA-B. DNA-B is more compact, and its level of gene transcription is higher compared to DNA-A. Based on these observations, which of the following statements is likely to be correct?

a.) DNA-A has 2 positive supercoils and DNA-B has 2 negative supercoils.

b.) DNA-A has 2 positive supercoils and DNA-B has 4 negative supercoils.

c.)DNA-A has 4 positive supercoils and DNA-B has 2 negative supercoils.

d.) DNA-A has 4 negative supercoils and DNA-B has 2 positive supercoils.

b.) DNA-A has 2 positive supercoils and DNA-B has 4 negative supercoils.

A chromosome territory is a region..

a.) of a chromosome that carries a cluster of genes

b.) of a chromsome that has particular sets of DNA-binding proteins

c.) in a cell nucleus that is occupied by a single chromosome

d.) in a dividing cell where a chromosome will travel via the spindle apparatus

c.) in a cell nucleus that is occupied by a single chromosome

When comparing the yeast genome (a simple eukaryote) to the human genome (a complex eukaryote), why is the human genome so much larger?

a.) the human genome has more genes

b.) the human genome has more repetitive DNA

c.) the human genome has more G's and C's compared to A's and T's

d.) both a and b are correct

d.) both a and b are correct

What is the underlying structural reason why DNA can be replicated to produce two double helices with the identical base sequences?

a.) base stacking

b.) because the strands are antiparallel

c.) the AT/GC rule

d.) because the DNA polymerase can make DNA only in the 5' to 3' direction

c.) the AT/GC rule

What are the expected results for the Meselson and Stahl experiment after 4 generations (i.e, 4 rounds of DNA replication in the presence of light nitrogen)? Note: during generation zero, the DNA is all heavy, and subsequent generations only make light DNA.

a.) 1/4 half heavy, 3/4 light

b.) 1/8 half heavy, 7/8 light

c.) 1/16 half heavy, 15/16 light

d.) 1/32 half heavy, 31/32 light

b.) 1/8 half heavy, 7/8 light

At the E.coli origin of replication, the DNA begins to unwind at the...

a.) DNaA boxes

b.) AT-rich region

c.) GATC methylation sites

d.) None of the above

b.) AT-rich region

In order to replicate the entire circular chromosome of E.coli, how many replication forks are used?

a.) one

b.) two

c.) four

d.) many

b.) two

The two things the DNA polymerase cannot do is to

a.) synthesize DNA in the 5' to 3' direction and begin synthesis on a bare template strand.

b.) synthesize DNA in the 3' to 5' direction and begin synthesis on a bare template strand.

c.) use an RNA primer and proofread the DNA.

d.) proofread the DNA and synthesize the DNA in the 5' to 3' direction.

b.) synthesize DNA in the 3' to 5' direction and begin synthesis on a bare template strand.

In the leading strand, DNA is made in the direction _____ the replication fork and is made as______.

a.) toward, one continuous strand

b.) away from, one continuous strand

c.) toward, Okazaki fragments

d.) away from, Okazaki fragments

a.) toward, one continuous strand

Which of the following is not found in a replisome?

a.) two DNA polymerases

b.) DNA ligase

c.) primase

d.) helicase

b.) DNA ligase

The proofreading function of DNA polymerase involves the recognition of a ______ and the removal of a short segment of DNA in the ______ direction.

a.) missing base, 5' to 3'

b.) base mismatch, 5' to 3'

c.) missing base, 3' to 5'

d.) base mismatch, 3' to 5'

d.) base mismatch, 3' to 5'

Below is a DNA molecule, with the ends labeled A, B, C and D. Which ends are extended by telomerase?

A 5'-----------------------------------------------3' B

C 3'-----------------------------------------------5' D

a.) A and C

b.) A and D

c.) B and D

d.) B and C

d.) B and C

LTP: If the gene you chose for the Progress Report of Safety and Ethics involves producing a product that is consumed by humans, your progress report should not involve which of the following:

a.) How you will conduct clinical trials

b.) What warnings you might provide to consumers

c.) How you will get FDA approval

d.) Whether there are regulatory issues associated with the sale of the product

a.) How you will conduct clinical trials

Which of the following is not an advantage of gene regulation?

a.) Mutability: increase the rate of mutation of genes associated with metabolism.

b.) Efficiency: only make proteins when they are needed.

c.) Specialization: only make proteins in particular cell types.

d.) Development: only make proteins at particular stages of development.

a.) Mutability: increase the rate of mutation of genes associated with metabolism.

A small effector molecule induces transcription. Which combination is below is consistent with this idea?

a.) repressor and inducer

b.) activator and inhibitor

c.) repressor and corepressor

d.) none of the above

a.) repressor and inducer

With regard to lac operon regulation via catbolite activator protein (CAP), which of the following statements is incorrect?

a.) CAP binds to the DNA when cAMP is bound to CAP.

b.) Glucose lowers cAMP levels.

c.) When CAP binds to the DNA, the transcription of the lac operon is inhibited.

d.) CAP is dimer that binds two molecules of cAMP.

c.) When CAP binds to the DNA, the transcription of the lac operon is inhibited.

Let's suppose you have isolated a mutant strain of E. coli in which the lac operon is constitutively expressed. You create a merozygote in which the mutant strain also contains an F' factor with a normal lac operon and a normal lacI gene. You then compare the mutant strain and the merozygote with regard to their β-galactosidase activities in the presence and absence of lactose. You obtain the following results:

Strain- Addition of lactose (no glucose)- Amount β-Galactosidase

Normal -Yes- 100

Mutant -No -100

Mutant -Yes -100

Merozygote -No- 100

Merozygote - Yes - 200

Which of the following is consistent with these data?

a.) The mutation is in the lacI gene and results in a lac repressor that cannot bind to the operator.

b.) The mutation is in the lac operator and prevents the lac repressor from binding to the operator.

c.) The mutation is in the lacI gene and results in a lac repressor that cannot bind allolactose.

d.) All of the above.

b.) The mutation is in the lac operator and prevents the lac repressor from binding to the operator.

For a riboswitch that control transcription, the binding of a small molecule such as TPP controls whether the RNA

a.) has an antiterminator or terminator stem-loop.

b.) has a Shine-Dalgarno antisequestor or the Shine-Dalgarno sequence in a stem-loop.

c.) is degraded from its 5' end.

d.) has both a and b.

a.) has an antiterminator or terminator stem-loop.

What is the role of mediator with regard to eukaryotic gene regulation?

a.) mediator controls the switch to the elongation phase of transcription

b.) mediator controls whether of not RNA polymerase can bind to the core promoter

c.) mediator causes histones to be displaced from the core promoter

d.) mediator controls whether of not TFIID can bind to the core promoter

a.) mediator controls the switch to the elongation phase of transcription

With regard to eukaryotic gene transcription, histones are not removed during...

a.) the formation of preinitiation complex

b.) transcriptional elongation

c.) phosphorylation of CTD

d.) the formation of nucleosome-free regions

c.) phosphorylation of CTD

The following list describes events that are required for transcription of a eukaryotic gene. Put them in the correct order.

1. Chromatin remodeling and histone modification

2. Formation of the pre-initiation complex

3. Elongation

4. Binding of activators

a.) 2, 4, 1, 3

b.) 1, 4, 2, 3

c.) 4, 1, 2, 3

d.) 1, 2, 4, 3

c.) 4, 1, 2, 3 (binding of activators, chromatin remodeling and histone modification, formation of pre-initiation complex, elongation)

Which of the following does not happen for the glucocorticoid receptor to activate a gene?

a.) Protein-protein interaction (e.g., dimer formation)

b.) Covalent modification of the glucocorticoid receptor

c.) The binding of a small effector molecule to the glucocorticoid receptor subunits

d.) All of the above happen.

b.) Covalent modification of the glucocorticoid receptor

Which of the following phenomena could you studying using Chlp-Seq?

a.) to see if a regulatory transcription factor binds to mediator and/or TFIID

b.) to measure the level of transcription of a given gene in real time

c.) to analyze the bonding of protein(s) to DNA on genome-wide scale

d.) to determine if a mutation at a regulatory site alters the transcription level of a given gene

c.) to analyze the bonding of protein(s) to DNA on genome-wide scale

Which of the following is not a function of heterochromatin formation?

a.) gene silencing

b.) prevention of transposable element movement

c.) removal of histones

d.) prevention of viral proliferation

c.) removal of histones

Due to imprinting, the Igf2 gene is activated because ______________ of the ICR and DMR _________ occur during _____________.

a.) covalent histone modification, does, oogenesis

b.) DNA methylation, does not, spermatogenesis

c.) DNA methylation, does, spermatogenesis

d.) DNA methylation, does not, oogenesis

c.) DNA methylation, does, spermatogenesis

Which of the following is not one of the steps of X-inactivation that occurs during embryonic development in female mammals?

a.) binding and spreading of Xist RNA along the inactivated chromosome

b.) expression of the Tsix gene on the inactivated X chromosome

c.) X chromosome pairing

d.) shift of the pluripotency factors and CTCFs to the active X chromosome

b.) expression of the Tsix gene on the inactivated X chromosome

Which of the following possibilities could explain how PcG (polycomb group) complexes are able to silence genes?

a.) the compaction of nucleosomes

b.) the attachment of ubiquitin to histone proteins

c.) the direct inhibition of transcription factors, such as TFIID

d.) all of the above

d.) all of the above

The Avy allele of the Agouti gene involves the insertion of a transposable element upstream from the normal Agouti promoter. Let's suppose that pregnant female mice are fed a diet that contains chemicals that increase DNA methylation. With regard to offspring carrying the Avy allele, this diet would

a.) cause their fur to be more yellow because the Agouti gene would tend to be over expressed.

b.) cause their fur to be more yellow because the Agouti gene would tend to be under expressed.

c.) cause their fur to be less yellow (more dark brown) because the Agouti gene would tend to be over expressed.

d.) cause their fur to be less yellow (more dark brown) because the Agouti gene would tend to be under expressed.

d.) cause their fur to be less yellow (more dark brown) because the Agouti gene would tend to be under expressed.

In the image below, the ncRNA is acting as a

a.) blocker

b.) guide

c.) scaffold

d.) decoy

b.) guide

Which of the following is something that HOTAIR ncRNA cannot bind to?

a.) PRC2 complex

b.) LSD1 complex

c.) GA-rich regions

d.) miRNA

d.) miRNA

Which of the following is not one of the steps in RNA interference (RNAi) that occurs with miRNA (microRNA)?

a.) transcription to produce Pri-miRNA

b.) cleavage of pre-miRNA by exportin 5

c.) binding of miRNA to form RISC

d.) binding of RISC to a complementary mRNA

b.) cleavage of pre-miRNA by exportin 5

Let's suppose a bacterium is part of a lineage that has been previously exposed to bacteriophage lambda. The ancestors to this bacterium were able to mount an attack against bacteriophage lambda via the CRISPR-Cas9 system. If this bacterium is now exposed to bacteriophage lambda, which phase(s) of the CRISPR-Cas9 system would be necessary for it to destroy bacteriophage lambda?

a.) adaptation only

b.) adaptation and interference

c.) expression and interference

d.) adaptation, expression, and interference

c.) expression and interference

LTP: Which of the following topics is not a topic for the progress report on commercialization?

a.) potential funding

b.) company personnel

c.) potential revenue

d.) future plans for other gene editing

d.) future plans for other gene editing