Into the Deep - ScienceKid.org

Descend below the sunlit zone into the midnight depths of the deep ocean — a world of crushing pressure, total darkness, and remarkable life forms, including the extraordinary ecosystems of hydrothermal vents.

10 XP

Reward

10

Questions

5–10 min

Time

Q1 Question 1 of 10

What is the mesopelagic (twilight) zone?

The ocean layer from about 200–1,000 meters where some dim light penetrates but photosynthesis is not possible The deepest zone of the ocean below 6,000 meters The surface zone where most photosynthesis occurs The zone immediately above the ocean floor

Q2 Question 2 of 10

How does water pressure change as you descend deeper into the ocean?

Pressure increases by about 1 atmosphere (10 m of water) for every 10 meters of depth Pressure remains constant throughout the ocean Pressure decreases with depth because water becomes more compressed Pressure only becomes significant below 5,000 meters

Q3 Question 3 of 10

What is bioluminescence, and how is it used by deep-sea animals?

The production of light by living organisms through chemical reactions, used for luring prey, communication, and camouflage A reflection of sunlight from the ocean surface Light emitted by minerals in the ocean floor A glow caused by radioactive isotopes in deep-sea water

Q4 Question 4 of 10

What are hydrothermal vents?

Fissures in the deep ocean floor where superheated, mineral-rich water erupts from the Earth's crust Cold-water springs that create oxygen-rich zones on the ocean floor Underwater volcanoes that erupt lava on the seafloor Warm, shallow underwater pools found in tropical regions

Q5 Question 5 of 10

What process supports life at hydrothermal vents instead of photosynthesis?

Chemosynthesis — bacteria convert chemicals from the vent fluid into energy Photosynthesis using reflected light from the ocean surface Decomposition of organic matter falling from the surface Nuclear energy released from radioactive minerals

Q6 Question 6 of 10

What is 'marine snow'?

A continuous rain of tiny organic particles — dead plankton, fecal pellets, and debris — that sinks from surface waters into the deep ocean Ice crystals that form in cold polar ocean water near the surface White mineral deposits around hydrothermal vents Bubbles of gas released from the ocean floor

Q7 Question 7 of 10

What is the hadal zone?

Ocean regions deeper than 6,000 meters, primarily found in ocean trenches The area immediately surrounding hydrothermal vents Any ocean region with no detectable light The ocean floor between 1,000 and 4,000 meters

Q8 Question 8 of 10

Why do many deep-sea fish have very large eyes or no eyes at all?

In the faint light of the twilight zone, large eyes detect dim light; in total darkness, eyes are useless so some species lost them entirely Large eyes help deep-sea fish see in color, while small eyes see in black and white All deep-sea fish have no eyes because deep water is always completely dark Eye size in deep-sea fish is unrelated to light availability

Q9 Question 9 of 10

What is a 'cold seep' on the deep ocean floor?

A seepage of methane, hydrogen sulfide, or other chemicals from the seafloor that supports chemosynthetic ecosystems A zone of unusually cold water caused by polar currents A freshwater spring on the ocean floor An area where icebergs melt and release cold freshwater

Q10 Question 10 of 10

Why is the deep ocean considered one of the least explored places on Earth?

Extreme pressure, darkness, and cold make it technically very challenging and expensive to reach and explore There is no life in the deep ocean, so there is no reason to explore it International laws prevent exploration of deep-sea regions The deep ocean has already been fully mapped and explored

Report a Problem