Biology / Unit 10 Bio 2275 short lesson, about 20 seconds
Insects versus Arachnids, Structurally Distinguished
Captions available
The idea
An insect, a hexapod, has three body regions, six legs, and antennae; an arachnid has two body regions, eight legs, no antennae.
In practice
A beetle's head, thorax, and abdomen carry six legs and antennae; a scorpion's fused head-thorax and abdomen carry eight legs and pincers.
Where people slip
"Bug," per Bio 2273, blurs these plans — this course reserves "insect" and "arachnid" as precise terms.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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