Biology / Unit 10 Bio 2257 short lesson, about 20 seconds
Mollusk Body Plan: Foot, Mantle, Visceral Mass
Captions available
The idea
A mollusk body organizes around three parts: a muscular foot for movement, a shell-secreting mantle, and a visceral mass housing organs.
In practice
A snail's foot glides it forward, its mantle secretes the shell, and its visceral mass sits enclosed within.
Where people slip
Not every mollusk keeps all three parts in obvious form — an octopus's foot is modified into arms, many lineages lost the shell.
Your place on the trail
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