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

Multiple Choice

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) Exons are noncoding segments of DNA that are present in the initial transcript,but are removed by splicing.