A
parts of the animal's body match up with other parts around a midpoint or line
symmetry
an animal with a backbone
vertebrate
an animal without a backbone
invertebrate
the simplest kind of invertebrate
sponge
an animal with armlike parts
cnidarians
tentacles
invertebrates with shells and soft bodies
mollusks
has spiny skin
echinoderm
an internal support structure
endoskeleton
have jointed legs and a body that is divided into sections
arthropods
hard covering that protects the body
exoskeleton
the simplest worm
flatworms
worms with thin bodies and pointed ends
roundworms
an earthworm is this kind of worm
segmented
keeps in moisture so the animal doesn't dry out
exoskeleton
have one pair of anetennae
insects
two pairs of antennae and two to three body sections
crustaceans
four pairs of legs, two body sections
arachnids
jellyfish and coral are this kind
cnidarians
sea urchins are this
echinoderms
only mollusks that live on land
snails and slugs
crabs and shrimp belong to this arhtropd group
crustaceans
these worms have a one-way digestive system
roundworms
these worms are identical, except for the head and tail ends
segmented
these worms have a ribbonlike body
flatworms