Single correct option
Bioluminescence evolved independently in bacteria, fungi, fish and insects, each lineage using a chemically distinct luciferin. This repeated convergence is unusual among biological traits and suggests that light production solves recurring survival problems: attracting prey, evading predators through camouflage, and signalling to potential mates. Yet the very flexibility that makes light such an effective signal also makes it exploitable, as seen in predatory fireflies that mimic the courtship flashes of other species to lure and consume unsuspecting males.
- A. Bioluminescence is a rare trait limited to fireflies and a handful of deep-sea fish, evolved primarily for courtship display.
- B. Because bioluminescence evolved independently many times to serve survival functions like predation, defence and signalling, it likely offers substantial fitness benefits, though its signalling uses remain vulnerable to deceptive mimicry.
- C. All bioluminescent organisms use an identical biochemical pathway, proving they share a single common evolutionary origin.
- D. Predatory mimicry in fireflies proves that bioluminescence is, on balance, more harmful than beneficial to the species that possess it.
Show answer and solution
Answer: (B) Because bioluminescence evolved independently many times to serve survival functions like predation, defence and signalling, it likely offers substantial fitness benefits, though its signalling uses remain vulnerable to deceptive mimicry.
The paragraph links repeated independent evolution to genuine survival value, lists three functional categories (prey attraction, predator evasion, signalling), and closes by noting signalling's vulnerability to mimicry. Option B synthesises all three elements accurately. Option A contradicts the breadth described ('bacteria, fungi, fish and insects'). Option C is factually wrong per the passage ('chemically distinct luciferin'). Option D overstates the mimicry point into an unsupported net-harm conclusion.
Saved on this device. Sign in or create a free account to keep it on every device.