Question

cDNA sequence is complementary to

• A. Gene sequence in genomic DNA
• B. Sequence in transcribed mRNA
• C. Sequence in spliced and mature mRNA
• D. Protein sequence

Answer 1

The correct option is C Sequence in spliced and mature mRNA

cDNA or complementary DNA is formed from mature mRNA using reverse transcriptase enzyme. The gene for a protein in genomic DNA has both coding and noncoding regions called as exons and introns respectively. If this DNA is used in this form for genetic transformation noncoding regions will also produce amino acids which can change the original protein. To avoid such complications genetic technologists make use of reverse transcriptase to make DNA from mature mRNA which has only coding sequences and no introns.