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WorksheetsChapter 12: 1-6
Total questions: 152
Worksheet time: 2hrs 46mins
The synthesis of an RNA copy of a gene is called ____________.
mutation
translation
transcription
replication
splicing
A unit of heredity can be broadly defined as a(n) (a) .
Changes in genetic material that can be inherited are known as (a) .
DNA is ________ to produce mRNA, which is then ________ to produce proteins that determine the traits an organism expresses.
transformed; translated
translated; transformed
transcribed; translated
translated; transcribed
transcribed; transformed
A gene is best described as a(n) __________.
subunit of a functional protein
single piece of DNA containing many hereditary blueprints
basic unit of inheritance
building block used to make chromosomes
What is the function of mRNA?
it catalyzes biochemical reactions required for cellular activities
it carries information from DNA to ribosomes
it contains the genetic information that is passes on from one generation to the next
it corrects mutations that occur in cells
What occurs when genetic material, that can be inherited, is changed?
duplications
stagnations
mutations
The process of creating a polypeptide from an mRNA template is known as (a) .
The central dogma of gene expression at the molecular level is comprised of two steps. What are they?
translation of DNA into a polypeptide
transcription of DNA into a polypeptide
translation of DNA into mRNA
transcription of DNA into mRNA
translation of mRNA into a polypeptide
Gene expression occurs in two steps. First, the cell transcribes the ________ to produce _________, which is then translated into _________.
(a)
In bacteria, transcription and translation occur in the ____________.
cytoplasm
mitochondria
nucleus
Messenger RNA carries information from the DNA to cellular components called (a) , which play a key role in the synthesis of polypeptides.
The characteristics of an organism are rooted in the activities of cellular (a) encoded by genes.
What is the process in which an mRNA molecule is used to synthesize a specific polypeptide on a ribosome?
translation
transcription
mutation
transformation
replication
The central dogma states that DNA is ________ into mRNA, which is then ____________ into a polypeptide.
(a)
Molecularly, a gene is an organized unit of _________ sequences that can be transcribed into RNA.
protein
regulatory
DNA
The synthesis of an RNA copy of a gene is called __________.
translation
mutation
splicing
transcription
replication
The transcription of non-coding RNAs can produce two important products: _________ RNA and __________ RNA.
(a)
In eukaryotes, transcription occurs in the _________, whereas translation takes place in the ____________.
(a)
Transfer RNA translates the language of __________ into that of amino acids.
proteins
mRNA
rRNA
enzymes
The _________ that constitute the genetic material provide a blueprint for the characteristics of every organism.
cells
membranes
organelles
genes
The promoter of a gene signals the beginning of what?
polydenylation
translation
splicing
replication
transcription
The copying of DNA into RNA occurs in the process called (a) .
What part of a gene signals the end of transcription?
silencer
regulatory region
promoter
terminator
stop codon
At the molecular level, a gene is define as an organized unit of DNA sequences that enables a segment of DNA to be transcribed into (a) , resulting in the formation of a functional product.
Which of the following are examples of non-coding RNA?
transfer RNA
pre-mRNA
ribosomal RNA
messenger RNA
polypeptides
During which stage of transcription does RNA polymerase bind to the promoter?
elongation
termination
initiation
What type of RNA translated the language if mRNA into that of amino acids?
Transfer RNA
Messenger RNA
Ribosomal RNA
The DNA strand that is complementary to the RNA strand produced during transcription is called the (a) strand.
Transcription begins at a site in DNA called the __________.
promoter
terminator
initiator
start codon
In a double-stranded DNA molecule, what DNA strand has almost the same sequence of bases as the mRNA that is synthesized from that molecule? Note that the only exception in sequence is that thymine in that DNA strand is replaced with uracil in the RNA.
the template strand
the coding strand
the primary strand
the RNA strand
In a transcriptional unit, the function of the terminator is to __________.
signal the end of transcription
signal the beginning of transcription
influence the rate of transcription
Which of the following events occur during the initiation stage of transcription?
DNA near the promoter is unwound to form an open complex
the RNA transcript dissociates from the DNA
RNA polymerase binds to the promoter
sigma factor is released
How does transcription differ in eukaryotes and bacteria?
eukaryotic transcription does not require a promoter sequence
bacteria have more types of RNA polymerase
the initiation stage of transcription is more complex in bacteria
eukaryotic transcription requires more proteins
Transcription factors are proteins that influence the ability of RNA polymerase to (a) genes.
During transcription, ribonucleotides are added to the __________.
5' end of the mRNA transcript
5' end of the lagging strand of DNA
3' end of the leading strand of DNA
3' end of the mRNA transcript
What RNA produced in eukaryotic transcription is the longest?
pre-mRNA
mature mRNA
transfer mRNA
Transcription is similar in bacteria and eukaryotes, except that (a) use more proteins.
Eukaryotic proteins that influence the ability of RNA polymerase to transcribe genes are called.
initiation factors
splicing factors
sigma factors
transcription factors
Before leaving the nucleur, pre-mRNA transcripts are modified by splicing, as well as the addition of ________ and _______ to the ends of the mRNA.
(a)
What end of a eukaryotic mRNA is modified by the addition of a cap?
3'
2'
5'
4'
True or false: In eukaryotes, pre-mRNA can be translated immediately without the need for modifications.
true
false
In eukaryotes, a mature mRNA has a modified guanosine covalently attached at its 5' end. This is due to a process called (a) .
In eukaryotes, transcription initially produces a longer RNA molecule called the (a) . This longer mRBA molecule is spliced, capped, and polyadenylated prior to translation.
How is the 3' end of a eukaryotic mRNA modified?
a poly A tail is added to it
it is spliced to the 5' end of another mRNA molecule
a methionine is added to it
a cap is added to it
a tRNA is added to it
How are eukaryotic mRNAs modified before leaving the nucleus?
exons are removed by splicing
introns are removed by splicing
a poly A tail is added to the 3' end
the initiator methionine is added
a cap is added to the 5' end
In mature mRNAs of eukaryotes, identify the event where a modified guanosine covalently attaches at the 5' end.
tailing
capping
splicing
The splicing of mRNA removes _______ from the mRNA molecule and joins the ________ together.
(a)
What is the name of the complex that removes introns from eukaryotic pre-mRNA molecules?
replisome
pre-initiation complex
proteasome
phagosome
spliceosome
What is a ribozyme?
an RNA molecule that can catalyze a chemical reaction
an enzyme that transcribes RNA
a multisubunit complex that synthesizes proteins
a protein that splices RNA molecules
The coding sequences of genes are found in ___________.
RNA polymerase
exons
promoters
terminators
introns
What happens during the process of mRNA splicing?
the mRNA binds to the small ribosomal subunit
introns are removed from the transcript
exons are joined together
amino acids are joined together with covalent bonds
a section is removed from the mRNA to form tRNA
The introns found in eukaryotic pre-mRNA are removed by a large complex called the (a) .
An RNA molecule that catalyzes a chemical reaction is call a(n) (a) .
The mechanism by which a single gene can encode two or more polypeptides with differences in their amino acid sequences is called (a) .
What is the purpose of the genetic code?
it specifies the relationship between mRNA and polypeptide sequences
it describes the flow of information from DNA to RNA to protein
it explains how chromosomes behave during meiosis
The genetic code is read in groups of three nucleotide bases known as (a) .
The total number of codons in our genetic code is (a) .
Because all organisms use the same code, with few exceptions, the genetic code is said to be nearly (a) .
The genetic code specifies the relationship between the sequence of nucleotides in __________ and the sequence of amino acids in a polypeptide.
tRNA
rRNA
mRNA
How many nucleotide bases are in one codon?
1
3
2
4
What amino acid is specified by the start codon?
proline
methionine
alanine
glycine
How many amino acids are specified by a single codon?
20
1
2
3
True or false: Bacteria and humans have the same genetic code, with rare exceptions.
true
false
A coding sequence specifies the amino acid sequence of a(n) (a) .
The three stop codons in mRNA are ______, _______, and ______.
(a)
The tri-nucleotide sequence that signals the end of protein synthesis is the (a) .
The start codon encodes the amino acid (a) .
The start codon defines the reading frame of a(n) (a) , and refers to the order in which codons are read during translation.
The portion of an mRNA sequence that specifies the amino acid sequence of a polypeptide is called the (a) sequence.
Beginning at the start codon, in what direction is each triplet read during translation?
from the 3' to the 5' end
from the 5' to the 3' end
from the N- to the C-terminus
from the C- to the N-terminus
What are the three stop codons?
UGA
AUG
UAG
UUA
UAA
Which RNA molecule involved in translation acts as an intermediary between an mRNA codon and an amino acid?
the tRNA
the rRNA
the pre-mRNA
the snRNA
A stop codon signifies the end of ________.
transformation
replication
transcription
translation
How many nucleotides are in an anticodon?
3
1
4
6
2
What defines the reading frame of an mRNA?
the ribosomal-binding site
the promoter sequence
the start codon
the nonsense codons
Which part of a tRNA molecule binds to a codon on mRNA to determine which amino acid will be added to a growing polypeptide?
3' end
5' end
amino acid
C-terminus
anticodon
Translation proceeds toward the ________ end of the mRNA molecule being translated.
N-terminus
3'
DNA-like
5'
C-terminus
The molecule that is attaches to an amino acid and has an anticodon that can base pair with a codon is called (a) .
What part of a tRNA binds to the codon of a messenger RNA molecule?
anticodon
acceptor system
codon
attached amino acid
In a tRNA molecule, the anticodon is a _________-base sequence.
four
two
three
six
The 3' end of the coding sequence in an mRNA molecule corresponds to the (a) -terminus of the polypeptide it encodes.
The _______-terminus of the polypeptide contains its first amino acid.
N
C
H
Which bonds link amino acids together in a polypeptide?
ionic bonds
hydrogen bonds
peptide bonds
glycosidic bonds
What is the function of the anticodon of a tRNA molecule?
it catalyzes the formation of peptide bonds
it binds to a codon on an mRNA molecule
it has an amino acid covalently attached to it
it base pairs with sequences on the rRNA
The components mRNA, tRNA, ribosomes, and translation factors must be made by a cell so that (a) can be synthesized.
Mutations in a gene that change the second codon will change the nucleotide sequence near the ________ of the mRNA and the amino acid at the protein's _______.
5' end; C-terminus
3' end; C-terminus
5' end; N-terminus
3' end; N-terminus
What structural features are common to all tRNAs?
A, P, and E sites
loop that attaches to the spliceosome
cloverleaf pattern with three stem-loops
acceptor stem for amino acid attachment
In order for translation to be accurate, the approximate amino acid must be attached to the __________.
5' end of the correct tRNA
codon of the correct mRNA
3' end of the correct tRNA
anticodon of the correct tRNA
In a polypeptide, amino acids are connected to one another by (a) bonds.
How is an mRNA sequence used to produce a specific amino acid sequence?
a codon on mRNA base pairs with an anticodon on a tRNA that carries the appropriate amino acid
when the ribosome recognizes a codon, it recruits aminoacyl-tRNA synthetase to add the correct amino acid to the polypeptide
each codon on mRNA is recognized by a specific amino acid
What enzymes attach amino acids to tRNA molecules
RNA polymerase
aminoacyl-tRNA synthetase
aminoacyl-tRNA transferases
ATP synthases
Which of the following components are necessary for translation?
spliceosomes
RNA polymerase
messenger RNA
transfer RNA
ribosomes
What must be attached to the 3' end of a tRNA molecule in order for translation to proceed properly?
an anticodon
an amino acid
a codon
ATP
Translation occurs on structures called (a) .
The enzymes that catalyze the attachment of amino acids to tRNA molecules are known as aminoacyl-tRNA (a) .
What are the two subunits of a ribosome called?
large and small subunits
transcription and translation subunits
α and β subunits
protein and rRNA subunits
During the process of charging a tRNA molecule, the enzyme aminoacyl-tRNA synthetase ____________.
first bind an aminoacyl tRNA, and then activates using energy from GTP
first activates an amino acid using ATP, and then binds a tRNA and transfers the amino acid to it
first activates an amino acid using GTP, and then binds a tRNA and transfers the amino acid to it
first binds an aminoacyl tRNA, and then activates using energy from ATP
In order for translation to be accurate, the appropriate amino acid must be attached to the _________.
anticodon of the correct tRNA
3' end of the correct tRNA
codon of the correct mRNA
5' end of the correct tRNA
What is the site of translation?
nucleus
plasma membrane
ribosome
golgi apparatus
The ribosomal subunits contain two types of macromolecules: ________ and ________.
(a)
In which part of a eukaryotic cell are most ribosomes found?
rough ER
mitochondria
cytosol
nucleus
Which macromolecules are found in ribosomes?
RNA
protein
polysaccharides
phospholipids
DNA
What are the names of the three sites where tRNA molecules bind to the ribosome?
the exit site
the aminoacyl site
the initiator site
the codon site
the peptidyl site
What macromolecules are found in ribosomes?
phospholipids
DNA
RNA
polysaccharides
protein
During the first stage of translation or (a) , a complex is formed between an mRNA molecule, the first tRNA, and the ribosomal subunits.
During the first stage of translation, the assembly of ribosomal subunits, mRNA, tRNA requires the help of proteins called (a) factors.
During the initiation stage of translation, the energy for the assembly of the complex is provided by (a) .
The three stages of translation are initiation, (a) , and termination.
Which of the following must assemble during the initiation stage of translation?
the ribosomal subunits
the first tRNA molecule
the mRNA molecule
the DNA molecule
In bacterial photosynthesis, how do the mRNA and the 16S rRNA bind to one another?
they are covalently attached to one another by the spliceosome
they are covalently attached to one another by ribosomal proteins
they base pair with each other
they associate indirectly via the initiator tRNA
What proteins facilitate interactions among mRNA, the ribosomal subunits, and the first tRNA molecule?
initiation facctors
elongation factors
ribosomal proteins
spliceosomal proteins
What molecule provides the energy for the assembly of an mRNA molecule, the first tRNA, and the ribosomal subunits during the initiation stage of translation?
GTP
ATP
glucose
methionine
During initiation of translation, the initiator tRNA recognizes the (a) codon in mRNA and binds to it.
In bacterial translation, the formation of the initiation complex begins when the small ribosomal subunit binds a(n) (a) molecule.
During the initiation stage of translation in bacteria, the mRNA first binds to _________.
the 16S rRNA of the small ribosomal subunit
an initiation factor
the 5S rRNA of the large ribosomal subunit
a molecule of GTP
an initiator tRNA
Which of these nucleotide sequences is the most commonly used start codon?
AUG
UGA
CCU
AUU
AGU
In eukaryotic species, the initiation phase of translation differs in two ways from the process in bacteria. First, instead of a ribosomal-binding sequence, eukaryotic mRNAs have a ______ cap at their 5' end. Secondly, in eukaryotes, the location of _______ codons is more variable.
adenosine ; start
guanosine ; start
cytosine ; start
adenosine ; stop
guanosine ; stop
During translation in eukaryotes, the start codon is recognized by ________.
the small ribosomal subunit
sigma factors
the large ribosomal subunits
initiation factors
Which tRNA recognizes and binds to the start codon in mRNA?
release tRNA
initiator tRNA
terminator tRNA
promoter tRNA
Identify the stage of translation in which polypeptide synthesis occurs.
initiation
termination
elongation
What is attached to a peptidyl tRNA?
an amino acid
ATP
a short polypeptide
GTP
The start codon in mRNA is the triplet (a) .
A charged tRNA molecule carrying a single amino acid binds to the A site because the anticodon in the tRNA has a sequence that is (a) to the codon in the mRNA.
How does the initiation phase pf translation differ between eukaryotic and bacterial species?
a different codon is used as the start codon in bacteria and eukaryotes
the small ribosomal subunit is not involved in binding the mRNA in eukaryotes
eukaryotic mRNAs have a cap at the 5' end that facilitates binding to the ribosome
the location of the start codon is more variable in eukaryotic species
Marilyn Kozak proposed that the small ribosomal subunit identifies a start codon by beginning at the _________ and then scans along the mRNA in the direction of the ________ in search of the AUG sequence.
C-terminus; N-terminus
N-terminus; C-terminus
5' end; 3' end
3' end; 5' end
The covalent bonding of amino acids to each other, one at a time, occurs during the (a) stage of translation.
To obtain the energy required for tRNA to bind to the A site, elongation factors hydrolyze _________.
glucose
ATP
the charged tRNA
GTP
A tRNA with a polypeptide attached to it is called a(n) ____________.
elongation factor
protein
peptidyl tRNA
aminoacyl tRNA
The peptidyl transfer reaction is catalyzed by a(n) _____________.
protein in the 30S subunit
rRNA in the 30S subunit
rRNA in the 50S subunit
protein in the 50S subunit
Because the anticodon in the tRNA is complementary to the codon in the mRNA, during elongation phase of translation, a charged tRNA carrying a single amino acid binds to the __________ site.
A
E
P
During protein synthesis, the translocation step results in the shifting of the tRNA in the ___________.
E to the P site
E site to the A site
A site to the P site
A site to the E site
P site to the A site
In the process of protein synthesis, what recognizes the three stop codons?
the anticodon on an uncharged tRNA
a protein called release factor
transcription factors
the large ribosomal subunit
During translation in eukaryotes, the start codon is recognized by __________.
initiation factors
the small ribosomal subunit
the large ribosomal subunit
sigma factors
Proteins functioning as elongation factors hydrolyze GTP to provide the energy for binding tRNA to the _________ site.
P
E
A
True or False: The structure of the release factor that recognizes stop codons is similar to the structure of a tRNA.
true
false
The movement of the polypeptide from the tRNA in the P site to the tRNA in the A site is referred to as __________.
aminoacyl binding
the termination reaction
peptide bonding
the translocation
the peptidyl transfer reaction
The third step of elongation involves the movement of the ribosome toward the 3' end of the mRNA by exactly one codon. This specific movement is called (a) .
During translation, the stop codons are recognized by a protein called a(n) (a) factor.
In translation, bacteria have two termination factors that recognize stop codons, RF1 and RF2. Eukaryotes have only one factor known as (a) .
Which of the following statements are true of bacterial translation?
there are two termination factors
translation occurs in the cytoplasm
an 80S ribosome is used
the initiator tRNA is bound to formyl-methionine
binding between the mRNA and ribosome requires a 7-methylguanosine cap
The translation factor mimics the structure of _________.
a tRNA molecule
the small ribosomal subunit
the spliceosome
the large ribosomal subunit
During bacterial translation, when a stop codon is encountered, a protein known as a(n) _____________ factor binds to the A site, which triggers the removal of the _____________ from the tRNA in the P site.
(a)
True or False: Eukaryotes have more translation termination factors than bacteria
true
false
These statements refer to translation in eukaryotes. Identify the ones that are true.
the initiator tRNA is bound to methionine
several termination factors are required
translation occurs in the nucleus
the ribosome consists of 40S and 60S subunits
binding of mRNA to the ribosome requires a ribosomal-binding site
Some antibiotics inhibit translation in bacteria because of structural differences between bacterial and eukaryotic (a) . This allows for the treatment of bacterial infections in humans.
Which of the following statements are true of bacterial translation?
translation occurs in the cytoplasm
binding between the mRNA and ribosome requires a 7-methylguanosine cap
there are two termination factors
the initiator tRNA is bound to formyl-methionine
an 80S ribosome is used
Which of the following types of RNA is NOT produced in bacteria?
rRNA
mRNA
pre-mRNA
tRNA
mRNA processing in eukaryotes (including 5' cap addition and splicing), occurs:
only after ribosomes bind the mRNA
only after Dicer converts the RNA from double stranded to single stranded
in the nucleus
in the cytoplasm
A difference between bacterial and eukaryotic translation is
translation can begin on an mRNA still being synthesized only in eukaryotes
bacteria uses a completely different genetic code can eukaryotes
a 5' cap is added to the mRNA before translation only in bacteria
modification to the 5' end of mRNA are required for ribosome binding only in eukaryotes
Which of the following is not involved in the initiation of translation?
mRNA
small ribosomal subunit
initiator tRNA
RNA polymerase
Alternative splicing that results in "exon skipping" is possible because:
exons can be removed during DNA replication
the spliceosome only "cuts out" introns that don't code for protein
the 5' end of an intron can react with the 3' end of any other intron
RNA polymerase can skip over some exons on the template strand
