Correct option is D
The correct answer is: (4) rRNA, tRNA, and mRNA encoding genes
Explanation:
In eukaryotic genes, introns are non-coding regions that are present within the coding regions of genes. These introns are typically found in the mRNA encoding genes, as they are part of the gene structure that is transcribed but later removed during RNA processing through splicing. In addition to mRNA encoding genes, rRNA and tRNA encoding genes can also have introns. Although the functional RNAs (like rRNA and tRNA) do not always get translated into proteins, their precursor forms include introns which are removed during RNA processing.
Information Booster:
Introns are non-coding regions in genes that are transcribed but removed during the process of RNA splicing.
They are present in mRNA, tRNA, and rRNA encoding genes in eukaryotes.
After transcription, splicing removes the introns and joins the remaining coding regions (exons) to form the mature mRNA.
In tRNA and rRNA encoding genes, introns are also present, though these RNAs are involved in translation rather than protein synthesis.
The presence of introns in both protein-coding and non-coding RNA genes suggests that their removal is an essential part of gene expression in eukaryotes.
Introns may have evolved to allow for alternative splicing, which increases the diversity of proteins and non-coding RNAs produced by a single gene.
Additional Information:
Option (1) rRNA and mRNA encoding genes but not in the tRNA encoding genes: This is incorrect because introns are present in all three types of encoding genes (rRNA, tRNA, mRNA) in eukaryotes.
Option (2) mRNA and tRNA encoding genes but not in the rRNA encoding genes: This is incorrect because introns are also present in rRNA encoding genes.
Option (3) mRNA encoding genes but not in the tRNA and rRNA encoding genes: This is incorrect because introns are present in tRNA and rRNA encoding genes as well.
