Scenario 1 – “Muscle‑Twitch Mice” (10 Points) A colony of la…
Scenario 1 – “Muscle‑Twitch Mice” (10 Points) A colony of lab mice has begun displaying sudden, short bursts of running whenever a loud sound occurs. Researchers discover a dominant allele T that encodes a hyperactive epinephrine receptor in skeletal‑muscle cells. Which change most directly explains the mice’s behavior? Hyper‑activity of this receptor would first increase the activity of which enzyme inside the muscle cell? To verify that the T allele produces a longer receptor protein, what step follows transcription of the T mRNA? If skeletal‑muscle cells alone express the epinephrine‑receptor gene, which explanation is most consistent? Researchers design primers flanking a 180 bp region that includes the T mutation. After PCR and agarose‑gel analysis they expect the mutant allele to show: