GENETICS AND EVOLUTION
MOLECULAR BASIS OF INHERITANCE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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exons and introns do not appear in the mature RNA
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exons appear but introns do not appear in the mature RNA
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introns appear but exons do not appear in the mature RNA
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both exons and introns appear in the mature RNA
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Detailed explanation-1: -Eukaryotic transcripts possess extra segments called introns or intervening sequences or noncoding sequences. They do not appear in mature or processed RNA. The functional coding sequences are called exons. Splicing is removal of introns and fusion of exons to form functional RNAs.
Detailed explanation-2: -Unlike the eukaryotic RNA immediately after transcription known as precursor messenger RNA, mature mRNA consists exclusively of exons and has all introns removed.
Detailed explanation-3: -exons appear but introns do not appear in the mature RNA.
Detailed explanation-4: -Eukaryotic primary mRNA consists of non-coding regions called introns and coding regions called exons. A special complex of proteins and RNA called the spliceosome must remove the introns and splice together the exons. In addition, the mRNA must also be modified at both ends.
Detailed explanation-5: -All eukaryotic genomes carry introns as parts of some gene structures and the introns are to be eliminated by a complex molecular machinery called the spliceosome comprising five snRNAs and more than 150 proteins [1, 2].