AP BIOLOGY

Detailed explanation-1: -The aphotic zone exists in depths below 1, 000 meters. Sunlight does not penetrate to these depths and the zone is bathed in darkness.

Detailed explanation-2: -These seafloor animals are called “benthos.” The most abundant types of benthos we find are brittle stars, sea cucumbers, sea stars, snails, clams, bristle worms, and, occasionally, crabs.

Detailed explanation-3: -Organisms living in the deep ocean must be adapted to survive under extreme pressure, limited light, cold temperatures, and other factors. Organisms living in the deep ocean must survive in a physical environment that is radically different from ocean habitats near the sea surface.

Detailed explanation-4: -Obviously, organisms who live at the deep sea vents can’t rely on the Sun; instead, many of them rely on the chemicals that come out of the vents-the process they use to create food is called chemosynthesis instead of photosynthesis.