FREE ESSAY ON ARTHROPODS

ARTHROPODS

Section 2 - Arthropods
Arthropods are invertebrates that have external skeleton, segmented bodies, and
appendages; they have open circulatory systems; they reproduce sexually
The outside skeleton is made of up of chitin and is called the exoskeleton; the process
of shedding an exoskeleton is called molting
The major groups of arthropods are crustaceans, arachnids, centipedes, millipedes, and
insects
Crustaceans:
-two or three body sections
-three pairs of appendages for chewing
-two pairs of antennae
-five or more pairs of legs
-develop into adults by metamorphosis
-live in water or damp places
-herbivores and carnivores
Arachnids (spiders and their relatives):
-two body sections
-eight legs
-no antennae
-breathe with book lungs or through tiny
openings in their exoskeleton
-many arachnids (spiders) are predators
-some arachnids (mites, ticks) are parasites
Centipedes and Millipedes:
-many segments
-centipedes have one pair of legs attached to
each segment; millipedes have two pairs
-centipedes are carnivores; millipedes are
herbivores