Question

A geneticist isolates a gene for a specific trait under study She also isolates the corresponding mRNA Upon comparison, the mRNA is found to contain 1,000 fewer bases than the DNA sequence. Did the geneticist isolate the wrong DNA? A) yes, mRNA is made from a DNA template and should be the same length as the gene sequence B) yes, the mRNA should contain more bases than the DNA sequence because bases flanking the gene are also C) no, the final mRNA contains only exons, the introns were D) no, the mRNA was partially degraded after it was removed

Answer 1

Answer:

C) no, the final mRNA contains only exons, the introns were removed

Explanation:

Exons are the coding areas while the introns are non-coding areas. Both of these are the sequences of nucleotide within a gene.

RNA splicing is a process which usually occurs as the RNA matures, causing the removal of introns ( non coding areas of the RNA ) i-e they will not be expressed in the final messenger RNA, while exons continue to form covalent bonds with one another to form a  mature mRNA.

So in the given scenario, Upon comparison, the mRNA is found to contain 1,000 fewer bases than the DNA sequence because the introns were removed by RNA splicing.

Hence option C) no, the final mRNA contains only exons, the introns were removed is correct.