| A | B |
|---|
| Gradually sloping end of a continent that extends beneath the ocean | Continental shelf |
| Ocean basin feature that dips steeply down from the continental shelf | Continental slope |
| Flat seafloor area from 4,000 m to 6,000 m below the ocean surface, formed by the deposition of sediments | Abyssal plain |
| Area where new ocean floor is formed when lava erupts through cracks in Earth's crust | Mid-Ocean ridge |
| Long, narrow, steep-sided depression in the seafloor formed where one crustal plate sinks beneath another | Trench |
| Food-making process using light energy from the Sun, carbon dioxide, and water | Photosynthesis |
| Food-making process using sulfur or nitrogen compounds, rather than light energy from the Sun, that is used by bacteria living near hydrothermal vents | Chemosynthesis |
| Marine organisms that drift in ocean currents | Plankton |
| Marine organisms that actively swim in the ocean | Nekton |
| Marine plants and animals that live on or in the ocean floor | Benthos |
| Area where a river meets the ocean that contains a mixture of freshwater and ocean water and provides an important habitat to many marine organisms | Estuary |
| Rigid, wave-resistant, ocean margin habitat built by corals from skeletal materials and calcium | Reef |
| Introduction of wastes to an environment, such as sewage and chemicals, that can damage organisms | Pollution |
