Old Quiz and Exam Questions Flashcards by Annika Gehl

How is the poly-A tail added to eukaryotic mRNA?

Poly-A polymerase adds it

How well did you know this?

Not at all

Perfectly

How are rRNAs produced?

The three largest ones are transcribed as a single unit, and then separated by endonucleases

How well did you know this?

Not at all

Perfectly

Eukaryotic introns must contain an “A” base that is important for splicing because

the 2’ OH of this adenosine attacks the linkage at the 5’ end of the intron in the first step of the splicing reaction

How well did you know this?

Not at all

Perfectly

A 5’ to 5’ phosphate bridge is found in

the 5’ cap of eukaryotic mRNAs

How well did you know this?

Not at all

Perfectly

Would you expect to find attenuation in control of gene expression in eukaryotes?

No, because in eukaryotes transcription and translation occur in separate compartments

How well did you know this?

Not at all

Perfectly

In eukaryotes, RNA polymerase II is responsible for

transcription of mRNAs

How well did you know this?

Not at all

Perfectly

The TATA binding protein is part of which basal transcription factor?

TFIID

How well did you know this?

Not at all

Perfectly

Which of the following is a common DNA binding domain?

a) ankyrin repeat
b) beta-sheet
c) leucine rich repeat
d) P-loop
e) zinc finger

zinc finger

How well did you know this?

Not at all

Perfectly

What does the HIV reverse transcriptase use as a primer?

a tRNA from the previous host cell carried in the vial capsid

How well did you know this?

Not at all

Perfectly

what is the function of the HIV protease?

it cleaves the viral polyproteins into individual proteins

How well did you know this?

Not at all

Perfectly

antigen binding to a specific B cell causes it to

proliferate and secrete IgG antibodies

How well did you know this?

Not at all

Perfectly

IgG antibodies consist of

two identical heavy chains and two identical light chains

How well did you know this?

Not at all

Perfectly

where does VDJ recombination occur?

in the DNA of the immunoglobulin loci in B cell precursors

How well did you know this?

Not at all

Perfectly

in V to J recombination in the light chain locus, what happens to the sequence between V and J cassettes?

it is removed as a circular DNA molecule and is degraded

How well did you know this?

Not at all

Perfectly

In eukaryotes, how is the first codon for translation determined?

translation starts with the first AUG codon after the 5’ cap

How well did you know this?

Not at all

Perfectly

if the sequence of a tRNA is 5’ ACG 3’, which codon will it read?

5’ CGU 3’

How well did you know this?

Not at all

Perfectly

Ribosomes create peptide bonds

that join the amino group of an amino acid attached to a tRNA in the “A” site to the carboxyl group of an amino acid joined to a tRNA in the “P” site

How well did you know this?

Not at all

Perfectly

termination of translation is determined by

the release factor binding to the stop codon in the A site of the ribosome

How well did you know this?

Not at all

Perfectly

A stretch of DNA reads 5’ GCCATT 3’ on the non-template strand. What is the sequence of the RNA transcribed from it?

5’ GCCAUU 3’

How well did you know this?

Not at all

Perfectly

what are properties of DNA polymerases and not RNA polymerases?

DNA polymerases need a primer and synthesize both strands of a nucleic acid molecule

How well did you know this?

Not at all

Perfectly

in prokayotes, transcription termination is determined by

a protein called rho

How well did you know this?

Not at all

Perfectly

UV causes

thymine dimers

How well did you know this?

Not at all

Perfectly

what human disease is caused by a defect in DNA repair?

Xeroderma pigmentosum

How well did you know this?

Not at all

Perfectly

which definition of a mutation is most accurate

mutations are any changes in an organism’s DNA sequence

How well did you know this?

Not at all

Perfectly

a stretch of protein-coding DNA with a sequence of GGCAT is mutated to GGGCAT. this is an example of

a frameshift

Incorrect bases introduced during DNA replication are usually corrected by

mismatch repair

What causes the structure of a DNA double helix to have a major groove and a minor groove?

the angles of the glycosidic bonds

What was the result of the Meselson-Stahl experiment

one band, half-heavy, half-light

In a Sanger DNA sequencing reaction using a capillary sequencing machine, the base at the 3' end of a newly-synthesized DNA strand is identified by

different fluorescent dyes attached to the dideoxy versions of each base

Banana plants have three copies of each chromosome. This is an example of

triploidy

In a sample of nucleic acid, 23% of the bases are adenine, 25% are cytosine, 26% are guanine and 26% are thymine. the nucleic acid is most likely

a single stranded DNA

What's a step of the gene editing process?

a Cas9 nuclease cuts a DNA molecule at a position determined by a guide RNA

Adenine is a purine

true

each base can have two tautomeric forms, which base-pair differently

true

each base has a 3' OH group

false

glycosidic bonds connect the sugars to the phosphates

false

hydrogen bonds hold the two strands together

true

deoxyribose sugars in the middle of a strand do not have any free OH groups

true

deamination of thymine creates uracil in DNA

false

DNA polymerase slips on the template and causes expansion of a trinucleotide repeat

true

spontaneous hydrolysis of a glycosidic bond cerates an apurinic site

true

a base analog such as a 5-bromouracil causes a single-base insertion

false

x-rays cause chromosome breaks

true

primers used consist entirely of RNA in

prokaryotes

telomerase is needed to complete replication of chromosomes in

prokaryotes and eukaryotes

each origin of DNA replication creates two replication forks

prokaryotes and eukaryotes

chromosomes are organized by wrapping DNA around histone proteins

eukaryotes

transcription of the genes encoding enzymes for the biosynthesis of the amino acid leucine to be

negatively regulated and repressible by leucine

what is a transcriptional enhancer

a DNA sequence distant from a promoter that is a binding site for transcription activator proteins

two adjacent genes on a chromosome are transcribed in opposite directions. this is possible because

the template strands are different

in steroid hormone signaling, the steroid hormone affects transcription by

binding to a steroid hormone receptor, causing it to enter the nucleus where it binds DNA

How does termination of RNA polymerase II transcription in eukaryotes occur?

once RNA polymerase passes the poly-A signal sequence, the RNA is cleaved

what are the types of chromatin remodeling effects?

replacement of some histone proteins with variant histone proteins, deacetylation of histones, methylation of amino acids in the histone N-terminal tails, and changes in the spacing of nucleosomes along the DNA

this large and complex general transcription factor has a DNA helicase activity that exposes the template for RNA polymerase II transcription. It also has a kinase activity that phosphorylates the C-terminal domain of the polymerase

TFIIH

tRNAs are transcribed by

RNA polymerase III

How do transcription activation domains affect rates on transcription initiation in eukaryotes?

they physically interact with the mediator in the pre-initiation complex

phosphorylation controls eukaryotic transcription activators

true

movement to the nucleus controls eukaryotic transcription activators

true

binding of an inhibitory subunit controls eukaryotic transcription activators

true

binding of a small molecule controls eukaryotic transcription activators

true

interaction with a nuclease controls eukaryotic transcription activators

false

glutamine-rich domains is a structural domain found in transcription factors

false

helix-turn-helix is a structural domain found in transcription factors

true

disulfide bridge is a structural domain found in transcription factors

false

zinc finger is a structural domain found in transcription factors

true

leucine zipper is a structural domain found in transcription factors

true

DNA replication and transcription require topoisomerase activity

false

DNA replication and transcription require a DNA template

true

DNA replication and transcription require a primer to initiate synthesis

false

DNA replication and transcription require ribonucleoside triphosphates

true

DNA replication and transcription require specific sites in the genome to start

true

tryptophan binding to the trp repressor protein reduces the rate of transcription initiation on the trp operon

true

formation of a hairpin loop including regions 3 and 4 of the attenuator reduces the rate of transcription initiation on the trp operon

true

formation of a hairpin loop including regions 2 and 3 of the attenuator reduces the rate of transcription initiation on the trp operon

false

absence of tryptophan reduces the rate of transcription initiation on the trp operon

false

a ribosome stalling on the trp codons in the leader peptide reduces the rate of transcription initiation on the trp operon

false

transcription and translation occur simultaneously in prokaryotes and eukaryotes

false

mediator is a part of the transcription initiation complex in eukaryotes but not in prokaryotes

true

in both prokaryotes and eukaryotes, RNA polymerases contain multiple different subunits

true

in both prokaryotes and eukaryotes, rRNAs and mRNAs are produced by different RNA polymerases

false

regulation of transcription in both prokaryotes and eukaryotes involves proteins that bind to specific DNA sequences to increase or decrease transcription levels

true

Old Quiz and Exam Questions Flashcards

(81 cards)