Glowing Sea Creatures

How and why do deep-sea animals make their own light?

Check your understanding

1. What is the main difference between a glow-in-the-dark sticker and a bioluminescent creature?
- A. Stickers use chemical reactions, while creatures use sunlight.
- B. Creatures create their own light through internal chemical reactions, while stickers store light.
- C. Stickers are made of living cells, while creatures are made of plastic.
- D. Creatures only glow during the day, while stickers only glow at night.
2. Which three things must collide to produce the 'cold light' of bioluminescence?
- A. Vinegar, baking soda, and water.
- B. Electricity, heat, and oxygen.
- C. Luciferin, oxygen, and the enzyme luciferase.
- D. Bacteria, sunlight, and salt.
3. Why is bioluminescence often called 'cold light'?
- A. Because it is found in the freezing cold deep ocean.
- B. Because the chemical reaction produces very little heat.
- C. Because the light itself feels freezing to the touch.
- D. Because it only happens in winter.
4. What are the specialized organs that store light-producing ingredients called?
- A. Photophores
- B. Flashlights
- C. Lenses
- D. Reflectors

1. How does an anglerfish use its glowing lure to its advantage?
- A. It uses the light to read in the dark.
- B. It scares away predators by blinking.
- C. It attracts curious prey toward its mouth so it can catch them.
- D. It uses the light to signal to other anglerfish.
2. What is the primary reason that most bioluminescence in the ocean is blue or green?
- A. Because these are the only colors sea creatures like.
- B. Because blue and green light travel the farthest through water.
- C. Because red light is too bright for the deep sea.
- D. Because these colors represent warning signals.
3. What is the goal of 'counter-illumination'?
- A. To attract a mate using rhythmic flashes.
- B. To confuse predators by creating a bright red light.
- C. To hide from predators by matching the light from the surface.
- D. To communicate with other members of the same species.
4. Why is a 'stoplight loosejaw' having red light considered a major advantage?
- A. Red light travels further than any other color in the deep ocean.
- B. It makes the fish look bigger to scare away sharks.
- C. Most other fish cannot see red light, allowing the loosejaw to hunt in secret.
- D. It helps the fish stay warm in the freezing water.

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