question_answer

Directions : (16 - 20)

Read the passage given below and answer the following questions.

A gene is defined as the functional unit of inheritance. Though there is no ambiguity that the genes are located on the DNA, it is difficult to literally tRNA or rRNA molecule also define a gene. However by defining a cistron as a segment of DNA coding for a polypeptide, the structural gene in a transcription unit could be said as monocistronic (e.g., eukaryotes) or polycistronic (e.g., prokaryotes). In eukaryotes, the monocistronic structural genes have interrupted coding sequences - the genes in eukaryotes are split genes or intervening sequences (IVS) or Junk DNA. The coding sequences or expressed sequences are defined as exons. Exons are said to be those sequence that appear in mature or processed RNA. The exons are interrupted by introns. Introns or intervening sequences do not appear in mature or processed RNA. The split-gene arrangement further complicates the definition of a gene in terms of a DNA segment. Inheritance of a character is also affected by promoter and regulatory sequences of a structural gene. Hence, sometime the regulatory sequences are loosely defined as regulatory genes, even though these sequences do not code for any RNA or protein.

Split genes or Intervening sequence (IVS) or Junk DNA is the feature of

A) Prokaryotes

B) Eukaryotes

C) Both of the above

D) None of the above