Tides, Depths & Reefs
The physics of the sea and the life that adapted to it.
What is the deepest known point in the ocean?
The water covering most of the planet, and what lives in it.
Most of the planet is ocean and most of that ocean is barely explored, which makes it the largest gap in our general knowledge of our own world. This category covers the basins and their scale, the physical processes, tides, salinity, currents, that govern them, and the creatures that live at every depth. It includes coral reefs, which support a disproportionate share of marine life from a tiny share of the seabed. The explanations connect an organism to the conditions it lives in, since almost every marine adaptation answers a problem of pressure, light or temperature.
7 quizzes in Oceans & Marine Life
The physics of the sea and the life that adapted to it.
What is the deepest known point in the ocean?
Bioluminescence, vent communities and the slow economy of a world without sunlight.
Which name is given to the ocean layer below roughly 1,000 metres, where sunlight never…
Whales, seals, sirenians and otters, and the equipment each one needed to leave the land.
Baleen whales feed by doing what?
Ten questions on the mammals that went back to the water and how they eat, dive, sing and sleep.
How does a baleen whale feed?
How a reef is built, what keeps it alive, and the animals that quietly run the place.
The single-celled algae that live inside coral tissue are known as what?
Ten questions on how seawater moves around the planet and what the ground beneath it actually looks like.
Spring tides, the largest tides of the month, happen when what occurs?
Cartilage instead of bone, electrical senses, and the fish that break every rule.
Sharks and rays differ from most fish because their skeletons are made of what?
7 published quizzes in this subject, 70 questions in total. Every one is researched, written and checked by hand.
The mix here is 2 easy, 3 medium and 2 hard. Difficulty is about how obscure the answers are, not how fast you have to be — there is no timer on any quiz.
About 7 minutes on average, ranging from 6 to 8. Playing every oceans & marine life quiz would take roughly 1 hour.
"Tides, Depths & Reefs" is the gentlest way in — 10 questions, about 6 minutes, rated easy.
No. Every quiz is free and playable straight away. An optional free account only saves your scores across devices.
Yes — every question has a short explanation of why the right answer is right, shown the moment you answer, whether you got it or not.