the base sequence of codons 57-58 in the cytoplasm beta5 reductase gene is CAGCGC. the mRNA produced upon transcripton of this gene will contain the sequence:

1)GCGCTG
2)CUGCGC
3)GCGCUG
4)CAGCGC
5)GUCGCG

Answer plz
edited by on 12/12/2013

Answer is : since the sequence inthe stem represents coding strand, the mRNA sequence must be identical except U fot T. No T in DNA means, no U in mRNA.

Can someone explain this plz

That means that your answer is #4. What you are lacking is the concept of what coding strand really means:

Coding strand
(is the antitemplate-is the actual gene that you are going to translate, always go 5' to 3')..... 5'- CAGCGC-3'
Template strand
Is the complement DNA for the coding strand the DNA that the RNA Polimerase is going to use) - 3'-GTCGCG-5'

mRNA (will use the template strand)............................................................................................-5'-GAGCGC-3'

So instead of doing all that you learn that the mRNA is the exact copy of the template strand, only that RNA have U instead of T.

Coding strand and template strand are not the same, they are opposite.

i didnt know that codons are on coding strand. now i got it. thanks for the xplanation.

but, you said that "So instead of doing all that you learn that the mRNA is the exact copy of the template strand, only that RNA have U instead of T."

mRNA is identical to coding strand.