Mon Prof Augmenté
How Seaweed Holds On and Drinks
Seaweed has no roots, so it grips rocks with a knotted base called a holdfast, like a claw. It soaks up water and minerals through its whole surface, while a land plant takes them in through its roots.
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In the picture
- Holdfast: the knotted base that grips the rock like a claw.
- Blade: the flat part that soaks up water and minerals all over.
- Oak roots: they pull water and minerals up from the soil.
Examples
- Kelp on a rocky shore stays in place during storms because its holdfast grips the stone.
- A sponge dropped in a bowl of water soaks it up on every side, a bit like a seaweed blade.
Key takeaways
- A holdfast only anchors the seaweed. It does not drink like a root.
- Seaweed takes in water and minerals through its whole body.
Carry on in the app
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