Question

RNA code for DNA codon ATG will be

• A. ATG
• B. AUG
• C. UAC
• D. TAC

Answer 1

Answer: (C)

UAC

RNA is synthesized by transcription of DNA template strand; therefore nucleotide sequence of newly formed RNA is complementary to its DNA template strand. DNA and RNA both have four bases; two purines and two pyrimidines, in the nucleotide chains. There are two purines namely adenine and guanine and three pyrimidines namely cytosine, thymine and uracil. The purines adenine and guanine and the pyrimidine cytosine are common to both DNA and RNA. DNA has the pyrimidine thymine; RNA has the pyrimidine uracil. A purine base pairs with pyrimidine and vice versa; adenine and guanine pair with thymine and cytosine; this makes option B wrong. Since RNA has uracil in place of thymine; adenine pairs with uracil in RNA. A DNA codon ATG will code for RNA codon “UAC”. Option C is correct. RNA has uracil in place of thymine; this makes options A and D wrong. The correct answer is C.