Quizmo

Quiz on Jellyfish

20 questions · June 28, 2026

Below is the full Quizmo quiz devoted to the theme "Jellyfish": each question, its four options, the correct answer highlighted and, where available, its source. A chance to brush up on your general knowledge and then test what you know.

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Question 1

Easy

Which organ do jellyfish completely lack?

Source: Jellyfish have thrived for over 500 million years with no brain at all, just a simple nerve net.

Question 2

Easy

What are jellyfish mostly made of?

Source: A jellyfish is roughly 95% water, so a beached one almost vanishes as it dries out.

Question 3

Easy

What survival trick do many deep-sea jellyfish rely on in the dark?

Source: Many produce their own light to startle predators or lure prey in the pitch-black deep.

Question 4

Easy

What do most jellyfish primarily feed on?

Source: Most jellyfish drift and snare tiny plankton and small fish with their stinging tentacles.

Question 5

Easy

Which jellyfish ranks among the most venomous animals on Earth?

Source: A box jellyfish's venom can stop a human heart within minutes, making it deadlier than most snakes.

Question 6

Easy

Which popular jellyfish-sting remedy has been thoroughly debunked?

Source: Urine can actually make stings worse; the famous beach hack is pure myth.

Question 7

Easy

How do jellyfish mainly move through the water?

Source: They pulse their bell to squirt water behind them, the same principle as a rocket engine.

Question 8

Easy

In SpongeBob SquarePants, jellyfish behave like which land animals?

Source: Bikini Bottom jellyfish buzz, sting, live in fields, and even produce jelly like honeybees.

Question 9

Easy

Which sea creature is a close stinging relative of the jellyfish?

Source: Anemones and jellyfish are both cnidarians, sharing the same stinging-cell weaponry.

Question 10

Easy

What is the common collective name for a group of jellyfish?

Source: A group of jellyfish is delightfully called a smack, though bloom and swarm are used too.

Question 11

Medium

One jellyfish can revert to its juvenile stage, earning it what nickname?

Source: Turritopsis dohrnii can rewind to a polyp and start over, dodging death indefinitely.

Question 12

Medium

In one Sherlock Holmes story, the surprising killer turns out to be what?

Source: In The Adventure of the Lion's Mane, the murderer is a giant stinging jellyfish, not a person.

Question 13

Medium

What record is the lion's mane jellyfish famous for holding?

Source: Its tentacles can trail over 30 metres, rivalling the blue whale for longest animal.

Question 14

Medium

Large jellyfish blooms have repeatedly forced what kind of facility to shut down?

Source: Swarms clog seawater intake pipes, shutting down coastal and even nuclear power plants.

Question 15

Medium

In many Asian cuisines, jellyfish is most commonly served how?

Source: Edible jellyfish is salted, dried and shredded into a crunchy marinated salad.

Question 16

Medium

Jellyfish flown into space in the 1990s later struggled with what on Earth?

Source: Born in orbit, they never learned to sense up from down and floundered under gravity back home.

Question 17

Medium

Upside-down jellyfish get much of their food from what living inside them?

Source: Like coral, they farm photosynthetic algae in their tissues and sunbathe belly-up to feed them.

Question 18

Hard

Unlike most jellyfish, the box jellyfish has a surprising number of what?

Source: Box jellyfish carry 24 eyes, some with real lenses, despite having no brain to process them.

Question 19

Hard

Which animal relies on jellyfish as a major part of its diet?

Source: Leatherback turtles gorge almost entirely on jellyfish, which is why floating plastic bags are so deadly to them.

Question 20

Hard

The Portuguese man o' war is often mistaken for a jellyfish but is actually what?

Source: It's a siphonophore, a colony of specialised animals working together as one floating creature.

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