UPSC Prelims 2016 GS Paper I · Q31 of 100 General Science easy

In the context of the developments in Bioinformatics, the term 'transcriptome', sometimes seen in the news, refers to

  1. (a) a range of enzymes used in genome editing
  2. (b) the full range of mRNA molecules expressed by an organism ✓ UPSC's answer
  3. (c) the description of the mechanism of gene expression
  4. (d) a mechanism of genetic mutations taking place in cells

Why the answer is (b)

• The transcriptome is the complete set of RNA transcripts — chiefly messenger RNA — produced by the genome of a cell or organism at a given time; it shows which genes are switched on and how strongly — option (b).

• Studied by RNA sequencing, it sits between the genome (DNA) and the proteome (proteins).

• Genome-editing enzymes (a) are tools like Cas9; gene-expression mechanism (c) and mutation mechanism (d) are processes, not the transcriptome.

• Hence option (b).

Why the other options are wrong

(a) a range of enzymes used in genome editing
Editing enzymes are not the transcriptome.
(c) the description of the mechanism of gene expression
The transcriptome is a set of molecules, not a description of a mechanism.
(d) a mechanism of genetic mutations taking place in cells
Mutation mechanisms are unrelated.

Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2016, held on 7 August 2016. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.

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