What are phytoplankton?

Tiny drifting plant-like organisms

Marine Biology Quiz: Can You Get 8 Out of 10?

This marine biology quiz covers whales, coral reefs, plankton, sharks, octopuses, kelp forests, deep-sea life and ocean zones. Can you get 8 out of 10 on the living things of the world's oceans?

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🎯 Daily Trivia Challenge • 🧠 10 Questions • ⏱️ 150 Seconds

Question 1 / 10 Time: 150s

Largest
What is the largest animal ever known?
Plankton
What are phytoplankton?
Coral
What are corals?
Octopus
How many hearts does an octopus have?
Sharks
What are shark skeletons made of?
Kelp
Kelp forests are made of what?
Deep
What is the dark ocean zone below about 1,000 meters called?
Turtles
How do sea turtles find their nesting beaches?
Whale song
Which whales are famous for long, complex songs?
Explorer
Which marine biologist was called Her Deepness?

Explanations: answer key for all 10 questions

Q1: What is the largest animal ever known?
Answer: Blue whale
Blue whales can reach about 30 meters.
Q2: What are phytoplankton?
Answer: Tiny drifting plant-like organisms
They produce about half of Earth's oxygen.
Q3: What are corals?
Answer: Animals that build reefs
Tiny polyps build limestone skeletons.
Q4: How many hearts does an octopus have?
Answer: Three
It also has blue blood.
Q5: What are shark skeletons made of?
Answer: Cartilage
Cartilage is lighter and flexible.
Q6: Kelp forests are made of what?
Answer: Giant algae
Kelp can grow about 50 centimeters a day.
Q7: What is the dark ocean zone below about 1,000 meters called?
Answer: Midnight zone
Many animals there glow.
Q8: How do sea turtles find their nesting beaches?
Answer: Using Earth's magnetic field
Females often return to where they hatched.
Q9: Which whales are famous for long, complex songs?
Answer: Humpback whales
Males sing in breeding season.
Q10: Which marine biologist was called Her Deepness?
Answer: Sylvia Earle
She led many deep-sea expeditions.

Marine Biology Quiz – Life in the Oceans

Oceans cover about 71% of Earth and hold an incredible variety of life. Marine biology studies everything from microscopic plankton to giant whales, and from sunlit coral reefs to the dark deep sea.

Ocean ecosystems are interconnected. Phytoplankton make food and oxygen, zooplankton feed fish and whales and coral reefs and kelp forests provide homes for countless species. Deep-sea creatures survive in darkness, cold and crushing pressure.

Oceans face threats from overfishing, pollution, plastic and warming waters that bleach coral. Marine biologists study these problems and help create protected areas to keep ocean life healthy.

What This Quiz Teaches

This quiz is for students and ocean lovers exploring marine biology.

Which animal is largest
What plankton does
What corals are
How octopuses differ
What lives in the deep sea

Did You Know?

More than 80% of the ocean is unexplored.
Greenland sharks can live over 250 years.
Mantis shrimp see many colors.
Dolphins sleep with half their brain.
The ocean holds about 97% of Earth's water.