Question

The portion of an eukaryotic gene which is transcribed but not translated is

• A. Exon
• B. Intron
• C. Cistron
• D. Codon

Answer 1

The correct option is B Intron

• The DNA is transcribed into messenger RNA which is further translated into protein.
• The transcribed m-RNA is known as heterogeneous RNA in its initial stages.
• It is changed into mature m-RNA through the sequential process. The heterogeneous RNA has certain coding and noncoding regions on it.
• The coding regions are known as exons while the noncoding regions are known as introns.
  The introns have the nonsense codon which cannot be translated so these are primmed off by a process known as splicing.
• The exons are joined together by ligase after removal of introns which turns it into a continuous strand of DNA.

So, the correct answer is option B.