How Sharks Regrow Their Teeth

Science Interactive lesson Free to play

Shark tooth replacement is the natural process by which sharks continuously grow and shed teeth throughout their lives, replacing lost or worn teeth with new ones instead of keeping a single fixed set. Unlike humans, who grow one permanent set of adult teeth, a shark's teeth have weak or no roots and fall out easily during feeding — but a replacement is always ready.

This works because shark teeth are arranged in many rows, not a single line. Behind each front tooth sit several hidden rows lined up like a queue. When a front tooth drops out, the row behind slides forward to take its place, much like a conveyor belt, and a new tooth begins forming at the back. This constant cycle means a shark never goes without teeth.

Learners will grasp the key ideas: teeth grow in rows, replacement is automatic and lifelong, and because sharks bite and tear rather than chew, losing a tooth causes no problem. Over a lifetime some sharks grow more than 30,000 teeth — a striking example of how animal bodies adapt to survive.

▶ Play the lesson — free, no signup

Want to create your own Spark? Sign up free — type any skill and LearnBuddy builds you a playable lesson.

Sign up free to create your own Spark

What this Spark covers

Frequently asked questions

How many teeth can a shark grow in its lifetime?
Some sharks grow more than 30,000 teeth over their whole life, because they keep replacing teeth again and again from the rows waiting behind the front ones.
Why do a shark's teeth fall out so easily?
Shark teeth have weak roots or no strong roots at all, so they come loose during biting and feeding. This is not a problem because a spare tooth is always ready to move forward and take its place.
Do sharks have more than one row of teeth?
Yes. Behind the visible front teeth are many hidden rows lined up like a queue, all ready to move forward when a front tooth is lost.
How is a shark's mouth like a conveyor belt?
When a front tooth falls out, the row of teeth behind it slides forward to fill the gap, and a brand-new tooth starts growing at the back — the same way items move along a conveyor belt.
Why can a shark lose a tooth without worrying?
Because a new tooth is already waiting right behind it, ready to move forward. Sharks also tear their food rather than chewing it, so a missing tooth does not stop them from eating.

More Sparks like this

Related practice papers

Related reads

Loved this Spark? Sign up free for AskBuddy AI tutoring, past-year papers, and unlimited Sparks.

Sign up free →