A mature mRNA transcript is produced from a primary mRNA transcript by A adding exons B adding introns C removing exons D removing introns. - Scottish Highers Human Biology - Question 6. - 2018

To produce a mature mRNA transcript from a primary mRNA transcript, the process involves the removal of non-coding sequences known as introns. During RNA processing, these introns are spliced out of the primary mRNA transcript, allowing the exons (which are coding sequences) to be joined together. This results in a mature mRNA transcript that is ready for translation into protein.