Echinoderms
Starfish, sea urchins, sea cucumbers and sand dollars: sea animals only, with a spiny skin over a skeleton of hard plates, and a body built in five parts around a middle. Water pumped through canals inside the body works hundreds of tiny tube feet, each with a sucker, which they walk and grip with. A starfish can grow back a lost arm.
Depth 1 · Foundation
You can recognise an echinoderm by its spiny skin and five-part body, explain how tube feet work, and say that they all live in the sea.
Sign in to prove what you know with a short quiz, see how deep you've gone, and earn XP for it.
Sign in with GoogleDepths of understanding
- 1
Foundation
You can recognise an echinoderm by its spiny skin and five-part body, explain how tube feet work, and say that they all live in the sea.
Your path here
What's still between you and Echinoderms, depth 1, in the order you can learn it.
Where it fits
Builds on
This concept