Download The diagram below shows the process of translation. PROCTOR

PROCTOR VERSION
3.4 D: Translation Quiz
1.
The diagram below shows the process of translation.
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PROCTOR VERSION
3.4 D: Translation Quiz
Which statement correctly identifies and describes the role of a structure shown in the diagram
that is involved in translation?
(A) Structure W is mRNA, which is involved in converting the nucleic acid code into an amino
acid sequence.
Distractor Rationale:
This answer suggests the student may understand that mRNA codons are translated into
amino acids, but does not understand that the structure indicated is a tRNA molecule
because it is transporting the amino acid that matches the RNA codon on the mRNA to the
ribosome.
(B) Structure X is the A site on the ribosome, which is composed of rRNA and proteins, and is
involved in the pairing of RNA codons with tRNA anticodons.
Rationale:
This answer suggests the student understands that the A site on the ribosome is composed
of rRNA and protein and helps to pair specific tRNA anticodons with mRNA codons so that
the proper amino acid can be attached to the polypeptide chain.
(C) Structure Y is tRNA, which “reads” the nucleic acid code and assembles the polypeptide.
Distractor Rationale:
This answer suggests the student may understand that tRNA plays a role in translation by
reading the codons on mRNA, but does not understand that the structure indicated is a
polypeptide chain and not tRNA because tRNA is not composed of amino acids.
(D) Structure Z is a growing polypeptide chain that is being synthesized by tRNA and rRNA, and
that will be folded and moved to its final location in or out of the cell.
Distractor Rationale:
This answer suggests the student may understand that polypeptides are synthesized based
on the interaction of rRNA and tRNA molecules assembling specific amino acids into a
chain, but does not understand that structure Z is mRNA and not a polypeptide because
polypeptides are not composed of nucleotides and do not pair with tRNA anticodons.
Aligned to: LO 3.4 CA 3.4: Represent Genetic Information
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PROCTOR VERSION
3.4 D: Translation Quiz
2.
The table below shows the relationship between mRNA codons and their amino acids.
Which mRNA segment shows the correct base sequence and directionality to produce the amino
acid sequence Met-Pro-Tyr-Ser-Leu-Ile?
(A) 5'-AUG CCC UAG UCC CUG AUC-3'
Distractor Rationale:
This answer suggests the student may understand that mRNA is transcribed in the 5'
3'
direction and that AUG is the start codon, but does not understand that this mRNA
sequence will not produce the given polypeptide because UAC codes for a stop codon and
not the amino acid Tyr.
(B) 3'-AUG CCG UAC UCG CUA AUA-5'
Distractor Rationale:
This answer suggests the student may understand how to convert mRNA codons to the
appropriate amino acids in translation, but does not understand that mRNA is always
translated in the 5'
3' direction.
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PROCTOR VERSION
3.4 D: Translation Quiz
(C) 5'-AUG CCA UAU UCC CUG AUC-3'
Rationale:
This answer suggests the student understands that mRNA is transcribed in the 5'
3'
direction and how to convert mRNA codons to the appropriate amino acids in transcription.
(D) 3'-AUG CCU UAU AGC CUG AUU-5'
Distractor Rationale:
This answer suggests the student may understand how to convert mRNA codons to the
appropriate amino acids in translation, but does not understand that mRNA is always
translated in the 5'
3' direction.
Aligned to: LO 3.4 CA 3.4: Represent Genetic Information
3.
The table below shows how mRNA codons are translated into amino acids.
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PROCTOR VERSION
3.4 D: Translation Quiz
A base substitution in which a guanine (G) base is replaced with a cytosine (C) base occurs on
the DNA template shown below.
Which statement best predicts what will happen to the polypeptide that is translated from this
altered DNA template?
(A) The substitution will result in no change in the polypeptide, because only the third base in
the affected codon will be changed, and only the first two bases in a codon determine the
amino acid that is translated.
Distractor Rationale:
This answer suggests the student may understand that the third base is not as influential as
the first and second bases in determining the translated amino acid in many mRNA codons,
but does not understand that this substitution will cause a significant change in the given
polypeptide sequence because this substitution changes the original codon to a stop codon.
(B) The substitution will result in a change in the second amino acid to Ile, because the codon
will be changed to AUC, which codes for the amino acid Ile.
Distractor Rationale:
This answer suggests the student may understand that the amino acid translated from the
affected codon will change as a result of the base substitution, but does not understand
that the polypeptide will stop because the anticodon that pairs with the codon UAG is a stop
codon.
(C) The substitution will result in only one amino acid being translated, because the second
codon will be changed to a stop codon, and translation will immediately stop.
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PROCTOR VERSION
3.4 D: Translation Quiz
Rationale:
This answer suggests the student understands that this base substitution would result in
the transcription of the codon UAG, which is a stop codon and would stop polypeptide
synthesis.
(D) The substitution will result in a change in all of the amino acids after the substitution,
because the new base will also change the codons translated after the substitution.
Distractor Rationale:
This answer suggests the student may understand that the base substitution changes the
affected codon, but does not understand that although translation of all of the codons
“downstream” of the substitution is stopped prematurely, the actual codons will remain
unchanged.
Aligned to: LO 3.4 CA 3.4: Represent Genetic Information
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PROCTOR VERSION
3.4 D: Translation Quiz
4.
The table below shows how mRNA codons are translated into amino acids.
Three bases are deleted in the mRNA sequence shown below.
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PROCTOR VERSION
3.4 D: Translation Quiz
Which statement best predicts the effect of the deletion on the resulting polypeptide?
(A) The third amino acid will be deleted from the polypeptide, but all other amino acids will
remain unchanged, because the second codon will still code for the same amino acid and no
other codons will be affected.
Rationale:
This answer suggests the student understands that a deletion of the three bases shown
would result in a shift of the bases so that the second codon still codes for arginine (CGU
and CGC both code for the Arg amino acid), and that the third amino acid would be removed
from the polypeptide.
(B) The second and third amino acids will be deleted from the polypeptide, but all other amino
acids will remain unchanged, because only the second and third codons will be affected by
the deletion.
Distractor Rationale:
This answer suggests the student may understand that the second and third codons are
affected by the deletion, but does not understand that this deletion does not change the
second amino acid and deletes the third, because the mRNA bases will shift, and that, while
the second codon will change, it will still code for the same amino acid (CGU and CGC both
code for the Arg amino acid).
(C) All of the amino acids after the first will be changed in the polypeptide, because the deletion
will create a shift beginning with the second, and this will change all codons that follow.
Distractor Rationale:
This answer suggests the student may understand that most deletions result in a frameshift
where all codons that follow the deletion are no longer functional, but does not understand
that this particular deletion of a triplet is an exception and does not cause a frameshift
because each codon is a triplet and because change in the second codon will result in the
same amino acid (CGU and CGC both code for the Arg amino acid).
(D) The Leu amino acid will be deleted from the polypeptide, but all other amino acids will
remain unchanged, because when only one codon is removed, all other codons will remain
unchanged.
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PROCTOR VERSION
3.4 D: Translation Quiz
Distractor Rationale:
This answer suggests the student may understand that the codon UUG codes for a leucine
(Leu) amino acid, but does not understand that the deletion occurred between two codons
that code for other amino acids and that UUG was not a codon in the original sequence.
Aligned to: LO 3.4 CA 3.4: Represent Genetic Information
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