What is the usual jellyfish life cycle?

Polyp, then free-swimming medusa

Immortal Jellyfish Quiz: Turritopsis and Reversing Its Life

This immortal jellyfish quiz meets Turritopsis dohrnii, the tiny animal that can reverse its life cycle. Play 10 interactive questions on its size of a few millimeters, the normal polyp to medusa cycle, reverting to a polyp after stress or injury, transdifferentiation of cells, how it was discovered, spreading around the world in ships' ballast water and why it can still die.

Start Immortal Jellyfish Quiz

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

Question 1 / 10 Time: 150s

Name
What is the immortal jellyfish's scientific name?
Size
About how big is it?
Cycle
What is the usual jellyfish life cycle?
Trick
What can the immortal jellyfish do?
Cells
What process changes its cells into new types?
Repeat
How many times might it reverse its life cycle?
Die
Can the immortal jellyfish still die?
Find
When was its reversal ability noticed?
Spread
How has it spread around the world?
Study
Why do scientists study it?

Explanations: answer key for all 10 questions

Q1: What is the immortal jellyfish's scientific name?
Answer: Turritopsis dohrnii
It is a hydrozoan.
Q2: About how big is it?
Answer: A few millimeters
It is tiny.
Q3: What is the usual jellyfish life cycle?
Answer: Polyp, then free-swimming medusa
Most medusae die after breeding.
Q4: What can the immortal jellyfish do?
Answer: Turn back into a polyp
Stress or injury can trigger it.
Q5: What process changes its cells into new types?
Answer: Transdifferentiation
Specialized cells become others.
Q6: How many times might it reverse its life cycle?
Answer: Possibly again and again
In theory it may not age out.
Q7: Can the immortal jellyfish still die?
Answer: Yes, from predators or disease
Immortal is a nickname.
Q8: When was its reversal ability noticed?
Answer: In the late 1980s and 1990s
Researchers saw it in the lab.
Q9: How has it spread around the world?
Answer: In ships' ballast water
It now lives in many oceans.
Q10: Why do scientists study it?
Answer: To learn about aging and cell renewal
Its genes are of interest.

The Jellyfish That Starts Over

The immortal jellyfish, Turritopsis dohrnii, is a tiny hydrozoan only a few millimeters across. Like many jellyfish, it begins as a polyp attached to a surface and buds off free-swimming medusae, the familiar jellyfish form.

When stressed, injured or aging, the medusa can turn back into a polyp, its cells changing into new types through a process called transdifferentiation. In theory it can repeat this again and again, earning its nickname. Researchers noticed the ability in the late 1980s and 1990s.

It is not truly immortal, since predators and disease still kill it. The species has spread around the world in ships' ballast water. Scientists study its genes to learn about aging and cell renewal.

What This Quiz Teaches

Science fans will enjoy these questions.

What the immortal jellyfish is
How its life cycle works
How it reverses aging
Whether it can die
Why scientists study it

Did You Know?

Its stomach is bright red.
It was first described in the 1800s.
Some other jellyfish show similar tricks.
Its full genome has been sequenced.
Most polyps are hard to spot.