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[ PASSAGE 1]

Bioluminescence

Bioluminescence describes the ability of an animal to produce and emit light. It results
from a chemical reaction in the animal in which luciferin (a light-emitting pigment),
luciferase (an enzyme), and proteins combine to create a glowing effect.

 Many marine animals experience bioluminescence as well as fungi and
microorganisms (such as some types of bacteria), and terrestrial invertebrates (such
as fireflies) also possess the ability to give off a glowing effect. These animals depend on
bioluminescence for various uses, one of which is counter-illumination camouflage. With
counter-illumination camouflage, an animal is able to emit a colored light that matches
its background, letting it blend in without being seen by other animals. This allows the
animal to either prey on other animals or protect itself from those preying on it.

Another use of bioluminescence can be to mimic other animals in order to blend in
with them. Certain deep sea fish such as the dragonfish copy the appearance of
other marine animals to attract their prey. Even some types of sharks, such as the
cookiecutter shark, use bioluminescence to blend in to their environment. Everything
except for a small part of their fins illuminates, making their fins look like small fish.
This tricks larger fish like the tuna and mackerel into coming near to try to feed on
them. This allows the shark to hunt for their food.

 A Furthermore, bioluminescence can serve as a signaling system for some animal
species, either to communicate with each other or to attract mates. B In one species of
fireflies, the females attract the males by giving off a light from their abdomens. C In
another species, the males signal with their illumination to attract the females. D For
click beetles, an orange light brings them together.

While animals may use bioluminescence to their advantage, humans also have various
uses for it. In the past, before lamps were invented, fish skins were dried and used in
coal mines in Europe as a source of light since candles could possibly cause explosions.
Other people caught fireflies and placed them in bottles so they could use them as light.
More recently, the luciferase enzyme has been used in multiple ways in the scientific
field, such as for genetic engineering and biomedical research. Furthermore, there are
hopes for utilizing the concept of bioluminescence to even light up streets or to use as
decorations. As a matter of fact, scientists have even created a bioluminescent plant.

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