Simple Animals

Vertebrates: are animals with backbones.

Invertebrates: are animas without backbones.

Symmetry: is the balanced arramgement of body parts around a center point or along a center line.

Sponges: are simple invertabrates that have pores.

Pores: is a small opening.

Stinging-cell animals: are animals with stinging cells and hollow saclike bodies that lack organs.

Tentacles: many stinging cell anoimals havs armlike parts.

Flatworm: are the simplest worms.

Tapeworm: is a kind of flatworm that has a falttened, ribbonlike body divide into sections.

Cyst: is a young worm with a protective covering.

Planarian: is a common freshwater flatworm that is not parasite.

Roundworm: are worms that have long bodies with pointed ends.

Hookworm: is roundworm that is parasite of humans.

Anus: is an opening through which undigested food leaves the body.

Segmented Worms: are worms with bodies divided into sections called segments.

Soft bodied animals: are animlas with soft body that ussually protected by a hard shell.

Mantle: the body is coverd by a thin fleshy tissue.