Deck 10: Gene Expression at the Molecular Level

Question 1

Which region of a structural gene contains the information that specifies an amino acid sequence?

A)promoter region
B)transcribed region
C)terminator
D)regulatory sequence
E)enhancer region

Answer 1

B

Question 2

The processes of transcription and translation are collectively known as

A)RNA processing.
B)gene duplication.
C)protein synthesis.
D)DNA synthesis.
E)gene expression.

Answer 2

E

Question 3

Which statement about RNA processing in eukaryotes is INCORRECT?

A)Introns are simply excised out of pre-mRNA to produce the mature mRNA.
B)A protein/RNA complex is used to remove introns from the pre-mRNA.
C)A poly A tail is added on to the 3' end of the mRNA.
D)A 7-methylguanosine cap is added on to the 5'end of the mRNA.
E)Processing occurs in the nucleus.

Answer 3

Introns are simply excised out of pre-mRNA to produce the mature mRNA.

Question 4

An organized unit of DNA sequences that enables a segment of DNA to be transcribed into RNA,and ultimately results in the formation of a functional product,is called a

A)chromosome.
B)trait.
C)allele.
D)gene.
E)expression.

Question 5

What process enables a single gene to encode two or more polypeptides that are different in their amino acid sequence?

A)Reverse transcription
B)Self-splicing
C)Capping
D)Alternative splicing
E)Regulatory splicing

Question 6

What basic features of transcription is NOT shared by both prokaryotes and eukaryotes?

A)Both prokaryotic and eukaryotic genes have a promoter site.
B)RNA polymerase transcribes genes in both prokaryotes and eukaryotes.
C)Gene transcription involves initiation,elongation,and termination in both prokaryotes and eukaryotes.
D)The complexity of protein components involved in transcription is similar for both prokaryotes and eukaryotes.
E)The initiation of transcription in both prokaryotes and eukaryotes involves the interactions of more than one protein.

Question 7

Intervening sequences that are transcribed,but not translated into protein are called

A)exons.
B)introns.
C)spliceosomes.
D)transposons.
E)transcription factors.

Question 8

What molecule(s)exhibits self-splicing?

A)rRNA
B)tRNA
C)mRNA
D)rRNA and tRNA
E)rRNA and mRNA

Question 9

If a cell's splicesomes were mutated so they no longer functioned normally,what consequences would result?

A)Introns would remain in the mature mRNA.
B)Exons would be missing in the mature mRNA.
C)Transcription would cease.
D)A functional protein would still be produceD.
E)RNA processing would remain intact.

Question 10

What protein influences the ability of RNA polymerase to transcribe genes?

A)DNA polymerases
B)DNA helicases
C)transcription factors
D)snRNPs
E)tRNA

Question 11

Transcription begins near a site in the DNA called the

A)promoter
B)enhancer
C)response element
D)transcription unit
E)regulatory sequence

Question 12

If a DNA template strand has a sequence of 3' TACAATGTAGCC 5',then the RNA produced from it will be

A)3'TACAATGTAGCC5'
B)5'ATGTTACATCGG3'
C)5'AUGUUACAUCGG3'
D)3'AUGUUACAUCGG5'
E)3'ATGTTACATCGG5'

Question 13

The transcription process in a eukaryotic gene directly produces

A)rRNA.
B)pre-mRNA.
C)mRNA.
D)DNA.
E)protein.

Question 14

What is the function of the poly A tail?

A)The poly A tail is required for the termination of translation,it is recognized by the release factor proteins
B)The poly A tail is required for the mRNA to resume its double helical structure
C)The poly A tail increases mRNA stability in eukaryotes
D)The poly A tail increases mRNA stability in prokaryotes
E)The poly A tail serves as a termination sequence for RNA polymerase III

Question 15

How many nucleotides are contained in a single codon?

A)1
B)3
C)4
D)6
E)9

Question 16

The process that produces mRNA from DNA is called

A)transcription.
B)translation.
C)replication.
D)processing.
E)post-translational modification.

Question 17

What protein is involved in synthesizing messenger RNA in eukaryotes?

A)RNA polymerase I
B)RNA polymerase II
C)RNA polymerase III
D)sigma factor
E)both RNA polymerase I and III

Question 18

What products of nonstructural genes are never translated?

A)transfer RNA
B)ribosomal RNA
C)messenger RNA
D)transfer RNA and ribosomal RNA
E)ribosomal RNA and messenger RNA

Question 19

Which statement about RNA polymerase in bacteria is INCORRECT?

A)It binds the promoter region of a gene.
B)It is bound to a sigma factor during initiation of transcription.
C)It synthesizes RNA.
D)It catalyzes the addition of nucleotides to the 5'end of a growing RNA stranD.
E)It dissociates from the DNA at the terminator.

Question 20

Which statement about the 5'cap and mRNA processing is TRUE?

A)The addition of a 5' cap to mRNA occurs while the pre-mRNA is being made.
B)The 5' cap helps stabilize the mature mRNA.
C)The 5' cap prevents the degradation of mature mRNA.
D)The 5' cap is added to the pre-mRNA by splicesomes.
E)The 5'cap is a group of adenosine molecules.

Question 21

RNA polymerase II of eukaryotes always requires more than one general transcription factor to initiate transcription.

Question 22

Which statement about tRNA is FALSE?

A)tRNAs of both eukaryotes and prokaryotes share common features
B)the two-dimensional structure of tRNAs exhibits a cloverleaf pattern
C)tRNAs are produced in the nucleus
D)functional tRNAs have been spliced by splicesomes
E)tRNAs possess an anticodon complementary to the codon

Question 23

The term N-terminus refers to the presence of this at one of the ends of a polypeptide.

A)oxygen atom
B)carboxyl group
C)amino group
D)carbonyl group
E)sulfate group

Question 24

Identify the anticodon sequence for an mRNA sequence that is 5'AUG-GGC-ACU-CAU3'.

A)3'AUG-GGC-ACU-CAU5'
B)3'UAC-CCG-UGA-GUA5'
C)5'AUG-GGC-ACU-CAU3'
D)5'UAC-CCG-UGA-GUA3'
E)3'TAC-CCG-TGA-GTA3'

Question 25

What is NOT a component of the translation machinery?

A)mRNA
B)tRNA
C)translation factors
D)ribosomes
E)protein polymerase

Question 26

How many distinct aminoacyl-tRNA synthetases does each cell make?

A)~1
B)~20
C)~60
D)~120
E)~180

Question 27

When an aminoacyl-tRNA synthetase charges a tRNA it results in the release of which molecule?

A)mRNA
B)ATP
C)AMP
D)pyrophosphate
E)AMP and pryophosphate

Question 28

A defective ribosome would have the MOST detrimental effect on what processes?

A)translation
B)replication
C)transcription
D)replication and transcription
E)replication and translation

Question 29

An mRNA sequence is 5'AUG-GGC-ACU-CAU-ACU-UAA3'F10,where AUG is the start codon and UAA is the stop codon.How many distinct aminoacyl-tRNA synthetases are required to translate the mRNA sequence?

A)2
B)3
C)4
D)5
E)6

Question 30

Which statement about the mRNA start codon is INCORRECT?

A)The start codon is only a few nucleotides from the ribosomal binding site.
B)The start codon is usually GGA.
C)The start codon is usually AUG.
D)The start codon specifies the amino acid,methionine.
E)The start codon defines the reading framE.

Question 31

What factors are recognized by the cell in order to recognize the stop codon and disassemble the translation machinery?

A)elongation factors
B)release factors
C)transcription factors
D)initiation factors
E)mRNA factors

Question 32

The molecule mRNA,which contains the information to make a polypeptide,is constructed from a DNA template.

Question 33

Because more than one codon can specify the same amino acid,the genetic code is said to be

A)repetitive.
B)redundant.
C)reverse.
D)degenerate.
E)wobbly.

Question 34

The most common eukaryotic ribosome carries out its function in the

A)Golgi apparatus.
B)nucleus.
C)cytosol.
D)mitochondria.
E)chloroplast.

Question 35

The amino acids of a growing polypeptide chain are held together by what kind of bond during the elongation stage of translation?

A)hydrogen
B)peptide
C)glycosidic
D)noncovalent
E)lactose

Question 36

What molecule indirectly provides the energy for translation?

A)ADP
B)ATP
C)GMP
D)GDP
E)GTP

Question 37

This mRNA transcript would result in what polypeptide sequence?
5'ACU-UUC-ACU-AUG-UUU-UUA-UCC-UCC-ACU-CCU-UGA 3'
Use the following codons and the amino acids they encode.
AUG = Start or Met;UUU,UUC = Phe;UUA,UUG = Leu;UCU,UCC = Ser;CCU,CCC = Pro;ACU,ACC = Thr;UGA = Stop.

A)Thr-Phe-Thr
B)Phe-Leu-Ser-Ser-Thr-Pro
C)Met-Phe-Leu-Ser-Ser-Thr-Pro
D)Thr-Phe-Thr-Phe-Leu-Ser-Ser-Thr-Pro
E)Met-Phe-Leu-Ser-Ser

Question 38

What serves as the "translator" or intermediary between an mRNA codon and an amino acid?

A)rRNA
B)snRNA
C)tRNA
D)siRNA
E)snRNPs

Question 39

A single gene always encodes for an enzyme.

Question 40

What enzyme catalyzes the attachment of amino acids to tRNA molecules?

A)helicase
B)topoisomerase
C)aminoacyl-tRNA synthetase
D)ribosome
E)translation factor

Question 41

More than one codon can specify the same amino acid.

Question 42

The termination of translation occurs when a release factor recognizes the stop codon.

Question 43

Because of the abundance of ribosomes,translation is NOT an energy costly process for the cell.

Question 44

When does the small ribosomal subunit bind to the translational complex in eukaryotic cells?

A)It is the first component to bind to the mRNA
B)After the initiator tRNA binds,but before the start codon has been found
C)After the large ribosomal subunit binds,but before the initiator tRNA binds
D)After the start codon has been found by initiator tRNA
E)The small ribosomal subunit binds the initiator tRNA and this complex is the first to bind to the mRNA

Question 45

As part of the transcriptional unit,regulatory sequences are the sites where RNA polymerase and transcription factors bind to regulate transcription.

Question 46

Translation is a relatively slow process.

Question 47

If Nirenberg and Leder had the technology,what would be a better substitute to using radiolabeled amino acids?

A)Radiolabeled proteins
B)Radiolabeled tRNAs
C)Ribosomes acids labeled with a fluorescent dye
D)Amino acids labeled with a fluorescent dye
E)All of these statements are correct

Question 48

Analyze each statement and decide which are CORRECT.

A)RNA polymerase simultaneously transcribes both strands of DNA
B)It is possible for one RNA polymerase to transcribe one strand of DNA in the 5' to 3' direction and another RNA polymerase to transcribe the complimentary strand of DNA in the 3' to 5' direction,producing two identical transcripts
C)It is possible for one RNA polymerase to transcribe one strand of DNA in the 5' to 3' direction and another RNA polymerase to transcribe the complimentary strand of DNA in the 5' to 3' direction,producing two identical transcripts
D)It is possible for one RNA polymerase to transcribe one strand of DNA in the 5' to 3' direction and another RNA polymerase to transcribe the complimentary strand of DNA in the 3' to 5' direction,producing two different transcripts
E)It is possible for one RNA polymerase to transcribe one strand of DNA in the 5' to 3' direction and another RNA polymerase to transcribe the complimentary strand of DNA in the 5' to 3' direction,producing two different transcripts

Question 49

All enzymes are proteins.

Question 50

tRNA contains the genetic code for producing a polypeptide.

Question 51

In eukaryotes,40S and 60S combine to form a 100S ribosome.

Question 52

Which amino acid would Nirenberg and Leder have found when they used the triplet UAG?

A)Isoleucine
B)Proline
C)Lysine
D)Threonine
E)None of these

Question 53

Evaluate the reasons ribosomal genes are useful for comparing evolutionary relationships among organisms?

A)Because there are many differences in these genes,even among closely related species
B)Because all organisms possess these genes and they can be compared with each other
C)Because these are the only genes that have been sequenced for every organism on Earth
D)Because ribosomes of prokaryotes and eukaryotes are identical
E)Because it is possible to compare the large subunit genes with the small subunit genes

Question 54

The cells of every organism make only a few different tRNA molecules encoded by the same gene.