As scientists were unraveling the mysteries associated with transcription and translation,they discovered there was not a one-to-one correspondence between nucleotide sequence of a gene and base sequence of the mRNA it codes for.They proposed the genes-in-pieces hypothesis.How can the genes-in-pieces hypothesis be explained?
A)Introns are noncoding segments of DNA that are present in the initial transcript,but are removed by splicing.
B)Introns are noncoding segments of DNA that are not read or transcribed by RNA polymerase II.
C)Exons are noncoding segments of DNA that are not read or transcribed by RNA polymerase II.
D)Several related genes are found in the genomes of humans and other animals.

Question

Quizplus · Accepted Answer

The genes-in-pieces hypothesis proposes that eukaryotic genes contain noncoding segments called introns that interrupt the coding sequence called exons. Introns are removed by the process of splicing after transcription to generate the mature mRNA that carries the genetic information for the synthesis of proteins. This explains why there is not a one-to-one correspondence between the nucleotide sequence of a gene and the base sequence of the mRNA it codes for. Therefore, option A is the best choice. Options B, C, and D are incorrect as they provide irrelevant or incorrect information.

As Scientists Were Unraveling the Mysteries Associated with Transcription and Translation,they