Ocean Ecosystems
1 / 15Explore the interconnected web of life in our oceans, from coral reefs to the open sea.
15 quick questionsNo sign-upFree to playTap an answer below to begin ↓
What percentage of the Earth's surface is covered by oceans?
About Ocean Ecosystems
Ocean Ecosystems is a free general knowledge quiz with 15 multiple-choice questions aimed at mixed difficulty. Explore the interconnected web of life in our oceans, from coral reefs to the open sea. A typical run takes about 7 minutes, hints are always one tap away, and your streak ticks up the first time you finish a game on a given day.
A few sample questions
1. What percentage of the Earth's surface is covered by oceans?
Answer: 71%
2. Coral reefs are sometimes called the 'rainforests of the sea' because they support what?
Answer: An enormous diversity of species
3. What tiny organisms form the base of most ocean food chains?
Answer: Phytoplankton
4. Mangrove forests along coastlines serve what important ecological function?
Answer: Providing nursery habitat for many fish species
5. What is ocean acidification primarily caused by?
Answer: Absorption of excess carbon dioxide from the atmosphere
Frequently asked questions
How many questions are in Ocean Ecosystems?
Ocean Ecosystems has 15 multiple-choice questions. Each one has four answer options and an explanation that appears after you answer, so you learn something even when you miss.
Is Ocean Ecosystems free to play?
Yes. The entire SeniorBrainGames catalog — including Ocean Ecosystems — is free, with no sign-up required, no time limits, and no ads on top of the game. It also works offline once the page has loaded once.
How long does Ocean Ecosystems take?
Most players finish Ocean Ecosystems in about 7 minutes. You can pause between questions, replay it as often as you like, and there is no penalty for taking your time — answers are explained after you submit them.
What's a good follow-up after Ocean Ecosystems?
If you enjoyed this general knowledge quiz, try the Daily Challenge — five rotating questions, refreshed every 24 hours, that count toward your streak. You can also use the Surprise Me button on the homepage to land on a different game type for variety.
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