Biology / Unit 2 Bio 0253 short lesson, about 20 seconds
Why Cell Size Is Limited
Captions available
The idea
As a cell grows, its volume increases faster than its surface area, so past some size the membrane cannot support the diffusion that volume needs.
In practice
Doubling a cube-shaped cell's side drops its surface-to-volume ratio from 6-to-1 to 3-to-1.
Where people slip
A cell hitting this limit does not stop growing outright — it divides, flattens, or develops specialized organelles.
Your place on the trail
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Builds on
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