What percentage of the Earth’s surface is covered by oceans?

Which is the largest ocean on Earth?

Coral reefs are mainly built by:

Which plant-like organism in the ocean produces a large amount of oxygen?

Which zone of the ocean receives the most sunlight?

What is the deepest part of the ocean?

Which ocean current warms Western Europe?

Which gas do marine plants mainly absorb during photosynthesis?

Which ocean is the smallest?

Sea turtles mainly breathe through:

Which marine ecosystem is known as the “rainforest of the sea”?

What is the study of ocean life called?

Which structure helps fish breathe underwater?

What is the hard outer skeleton of a crab called?

What type of animal is a jellyfish?

Which marine plant forms underwater forests?

What is the salty water habitat where rivers meet the sea called?

Which marine organism is responsible for harmful “red tides”?

Which ocean zone is completely dark?

What is the name of the tiny floating animals in the ocean?