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  1. #1
    Zoe MD is offline Newbie
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    transcription question

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    During RNA synthesis the template strand is TACG this sequence will produce which of the following?

    a. ATGC
    b. CGTA
    c. AUGC
    d. CGUA

  2. #2
    Zoe MD is offline Newbie
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    The answer is D
    why?
    RNA is antiparallel and complementary to the template strand.
    By conversion all base sequences are writtem 5-3 direction regardless the direction that they appear in the cell.

    Hint;
    cross all answer that have T, becuase you are looking for RNA, is no T in RNA.

    If they ask you the coding strand the answer will be b
    why?
    coding strand is identical to the mRNA with the exception that besides having U will have T

    Tricky !!!!

  3. #3
    blrman76 is offline Newbie 510 points
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    Quote Originally Posted by Zoe MD
    During RNA synthesis the template strand is TACG this sequence will produce which of the following?

    a. ATGC
    b. CGTA
    c. AUGC
    d. CGUA
    The answer is D.

    When a DNA sequence is given, it is in 5' to 3' direction.

    Template 5' TACG 3'
    mRNA 3' AUGC 5'

    So answer is D CGUA

    The coding strand on DNA will be CGTA[ same as mRNA except substitute T for U]
    Last edited by blrman76; 02-28-2006 at 08:59 AM.

  4. #4
    white-rose is offline Junior Member 510 points
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    I understood regarding the U in RNA and not T, but why is the correct answer not choice C?

  5. #5
    Bruno is offline Newbie 510 points
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    the correct answer is C indeed
    not D
    T=U
    Thymin in DNA maches Urazil in RNA sequence

  6. #6
    soon2bemd is offline Junior Member
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    answer D

    Answer C is 3 prime to 5 prime...you have to flip it to read 5 prime to 3 prime...therefore answer is D or 5'-CGUA-3'

  7. #7
    navpreet is offline Member 510 points
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    good one

    thanks.its a good one.

  8. #8
    white-rose is offline Junior Member 510 points
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    Quote Originally Posted by soon2bemd View Post
    Answer C is 3 prime to 5 prime...you have to flip it to read 5 prime to 3 prime...therefore answer is D or 5'-CGUA-3'
    That's very confusing because they haven't mentioned the 3' 5' ends. Unless FA or qbook gives the explanation of choosing the answer by flipping it over, how can we be sure? Especially on an exam where every mark counts. So plz tell me that you read it from an explanation in some dependable book!
    Thanks

  9. #9
    soon2bemd is offline Junior Member
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    even though the person who posted this question did not write in the 5'-3'...it is always assumed that a template strand is read 5'-3'....therefore if i put TACG...you should automatically assume that it is 5'-TAGC-3'...the other strand: 3'-AUCG-5'

    So in the answer choices it must be rewritten 5'-3' or 5'-GCUA-3'

    Can you see it now?

  10. #10
    buffy coat is offline Newbie 510 points
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    i completely to soon2bemd.
    the answer must be GCUA


    reason: By convention, always read any sequence as 5' to 3'

    cross out T from the sequence in templete coz RNA has U instead.

    TAGC from 5' to 3'

    so RNA from 3' to 5' will be AUCG but answer must be written in 5' to 3' as GCUA.


    i think this clears your doubt although its little tricky.
    keep sending questions like this.

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