The template strand of a DNA segment that codes for mRNA has the sequence: ATGCGT. Which tRNA anticodons would pair with the mRNA that is coded for by this sequence?

Question

A.  AUG CGU.
B.  ATG CGT.
C.  UAC GCA.
D.  UAG CGU.

Clarify Question
· What is the key concept addressed by the question?
· What type of thinking is required?
· What key words does the question contain and what do they mean?

Gather Content
· What do you already know about transcription and translation?

Consider Possibilities
· Consider the different answer options. Which can you rule out?

Choose Answer
· Given what you now know, what information and/or problem-solving approach is most likely to produce the correct answer?

Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

A.  AUG CGU.

Clarify Question
· What is the key concept addressed by the question?
        o This question addresses transcription and translation.
· What type of thinking is required?
        o This question is asking you to analyze the information given, using logic, to dissect the problem and determine the answer.
· What key words does the question contain and what do they mean?
        o The template strand of the DNA is the strand used to make the RNA copy. The RNA is paired up with the template strand, so it is complementary to it, not the same.
        o The tRNA anticodons are the three nucleotide sequences that base-pair with each codon of the mRNA. Each tRNA has one anticodon and carries one amino acid.

Gather Content
· What do you already know about transcription and translation?
        o You know that there are several steps from DNA to tRNAs. The DNA is transcribed into mRNA, then the mRNA is translated by the ribosome using tRNAs whose anticodons base pair with the mRNA.

Consider Possibilities
· Consider the different answer options. Which can you rule out?
        o What is different about the bases in RNA compared to DNA? RNA uses U, not T. This is true for tRNA as well as mRNA. So you can rule out the answer with T in the RNA.

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o What specifically are you being asked to describe? The question is asking you to name the tRNA anticodons that relate to the given DNA template strand. So you need to determine the corresponding mRNA, and then determine which anticodons would pair with the mRNA.
        o Is an mRNA the same as its DNA template strand, or complementary to it? The mRNA is complementary to the sequence of the template strand, because it is transcribed by base-pairing to it. So the mRNA is UACGCA.
        o The tRNAs have to base pair to the mRNA. So the tRNAs would read AUG CGU.

Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        o This question asked you to describe the tRNA anticodons that correspond to a given DNA template strand sequence.
        o The question required you to analyze the information given, using logic, to dissect the problem and determine the answer.
        o Did you recognize that the mRNA is complementary to the DNA template strand?
        o Did you recognize that the tRNAs would be complementary to the mRNA?
        o Did you remember that RNAs always use U instead of T?