Abyssal Ecosystems: Hydrothermal Vent Life Quiz

If these vents are formed by seawater seeping into cracks in the Earth's crust and being heated by magma, and if tectonic plate boundaries (ridges) are where the crust is thinnest, then we find these vents on the deep ocean floor.

If the ocean is thousands of meters deep, and if sunlight cannot reach depths below 1,000 meters, then the organisms living at the vents must rely on a different source of energy other than the sun.

If photosynthesis is the use of light to make energy, and if vent bacteria use chemical energy from hydrogen sulfide instead of light, then the scientific name for this process is chemosynthesis.

If an organism must survive in high-pressure, lightless, and chemical-rich environments, then specialized creatures like tube worms, yeti crabs, and vent shrimp fit this category, while plants like trees and seaweed cannot survive there.

If sunlight is unavailable for photosynthesis, and if the vents release energy-rich chemicals like hydrogen sulfide, then bacteria can act as the "plants" of the ecosystem by converting those chemicals into food for other animals.

If the water at the bottom of the ocean is under extreme pressure, and if pressure raises the boiling point of liquids, then the vent water can reach temperatures over 400 degrees Celsius without turning into steam.

If every ecosystem needs a primary producer to turn energy into food, and if bacteria are the only organisms at the vents capable of performing chemosynthesis, then they are the base of the food chain.

If hot vent water contains dissolved metals and sulfur, and if that hot water hits the freezing cold ocean water, then the minerals settle out as dark particles; if this looks like a cloud of soot, then we call them black smokers.

If the vents are deep under the sea, they have crushing pressure and no light; if they are volcanic, they release toxins; if they are in the deep sea, the surrounding water is cold. Therefore, all these are challenges.

If some bacteria use sulfur or methane to create energy, and if these processes can occur in environments where oxygen is very low or missing, then oxygen is not always a strict requirement for every form of chemosynthesis.

If a tube worm has a specialized organ called a trophosome, and if that organ is filled with billions of symbiotic bacteria that produce sugar, then the worm does not need to eat or digest food traditionally.

If humans had never seen these ecosystems until they used the submersible Alvin near the Galapagos Rift, and if that expedition occurred in the late 1970s, then the year of discovery was 1977.

If the average depth of a vent is 2,500 meters, and if human divers can only go down a few hundred meters, then we must use reinforced machines that can withstand the weight of the water above.

If the entire food web at the vent depends on bacteria performing chemosynthesis, and if those bacteria need the chemicals from the vent to survive, then stopping the chemical flow would cause the ecosystem to collapse.

If there is no light, eyes are not useful; if the water is heavy, pressure resistance is needed; if there is no sun, chemical energy is used. Fur is not found in deep-sea vent species.

If Europa has an icy crust with a salt-water ocean underneath, and if it has volcanic activity at the bottom, then scientists use Earth's vents as a model for possible life on that moon.

If the vents are located at mid-ocean ridges where tectonic plates pull apart, and if magma rises to fill those gaps, then that magma provides the thermal energy to heat the water in the vents.

If some specialized fish have adapted to live in the cold water near the vents to eat shrimp or worms, and if the eelpout is one of these known species, then fish are indeed part of the vent community.

If photosynthesis uses the sun's radiation to power the creation of sugar, and if chemosynthesis uses the breaking of chemical bonds in molecules like hydrogen sulfide, then the primary difference is the energy source.

If water has mass, and if the ocean is miles deep, then the gravity pulling on all that water creates a massive force; if that force is applied over an area, it is called pressure.