Practice question

Appearance of larger RNA species exclusively after induction, visualized on Northern blot, strongly suggests regulated alternative splicing rather than degradation or genomic alteration. Controlled induction may activate specific splicing factors resulting in retention of intronic sequences or inclusion of additional cassette exons, increasing transcript length. Such larger products remain polyadenylated and intact, differing from degradative smears that show smaller heterogeneous fragments. Since probe targets same gene, genomic duplication would affect Southern blot pattern, not RNA size. Hence observation reflects dynamic modulation of splice site choice altering isoform composition.