Q.27 All pseudogenes DO NOT code for a ________.
(A) protein with original function
(B) protein with altered function
(C) RNA with coding sequence
(D) RNA with regulatory function

Pseudogenes represent inactive genomic copies of functional genes that have lost their protein-coding ability due to mutations. The correct answer to the query “All pseudogenes DO NOT code for a ________” is (A) protein with original function, as pseudogenes universally fail to produce functional proteins matching their parental gene’s role.​

Correct Answer

Option (A) identifies the universal trait of pseudogenes. These sequences arise from gene duplication or retrotransposition and accumulate disabling mutations like frameshifts or premature stop codons, preventing translation into a protein that retains the original biological activity. By definition, no pseudogene encodes such a protein, distinguishing them from active genes.​

Option Explanations

Pseudogenes challenge the “junk DNA” label, as some exhibit regulatory roles despite lacking original protein function.

• (B) Protein with altered function: Incorrect, since rare cases exist where pseudogenes produce proteins with modified activities, such as small peptides influencing cellular processes.​

• (C) RNA with coding sequence: Incorrect, as certain transcribed pseudogenes retain open reading frames that could theoretically code for truncated or altered proteins, even if non-functional.​

• (D) RNA with regulatory function: Incorrect, because many pseudogenes generate non-coding RNAs like siRNAs or lncRNAs that modulate gene expression via RNAi or miRNA sponging.​