Final answer:
The largest ocean in the world is the Pacific Ocean, and the smallest is the Arctic Ocean. They are part of the Earth's marine biomes, which also include coral reefs and estuaries.
Step-by-step explanation:
The Pacific Ocean is the largest ocean in the world, where the vastness of the water body stretches from North America to South America and from Western Europe to Western Africa. On the other hand, the smallest ocean on Earth is the Arctic Ocean. The Arctic Ocean spans across a smaller geographic area in comparison to its counterparts like the Atlantic Ocean or the Indian Ocean. Both these oceans, including the Atlantic which borders countries like the United States, and areas such as Georgia, South Carolina, and Chesapeake Bay, as well as countries on the opposite shores such as Western Europe and Western Africa, contribute significantly to the planet's marine biomes, which include other bodies like the Mediterranean Sea, Nuevo Gulf in Argentina, and the Baltic Sea.
Marine biomes are the largest biomes on Earth, encompassing not just the open ocean, but also coral reefs and estuaries, which are unique in their mixing of salt water and fresh water. An important feature beneath the ocean's surface is the benthic realm, which stretches from the top to the bottom next to the continental shelf, while the entirety of the ocean's open water is referred to as the pelagic realm.