Which ocean is the largest on Earth?

What causes ocean tides?

Which marine animal is the largest in the world?

What is a coral reef mostly made of?

What is bioluminescence?

Which gas do sea plants like algae produce during photosynthesis?

Where is the Mariana Trench located?

Which type of water is found in oceans?

What do plankton provide to the ocean ecosystem?

What is the term for animals that live on the ocean floor?