Sentence Completion

Complete the sentence with ONE word from the passage for each blank.

Bioluminescence is the production of light by living organisms through a chemical reaction. In many marine species, a molecule called luciferin reacts with oxygen to release a cool glow that gives off almost no heat. Deep-sea fish use these flashes to lure prey, confuse predators, or attract mates. Certain fungi and insects, such as fireflies, rely on the same basic chemistry to communicate in the dark.

Bioluminescent light is created when luciferin combines with , and notably the resulting glow produces almost no .