Overview of Animal Kingdom and Major Phyla

Heterotrophs

Organisms that obtain energy by consuming others.

Multicellular

Organisms composed of multiple cells.

Porifera

Phylum of sponges; asymmetrical, no tissues.

Cnidaria

Phylum including jellyfish; diploblasts with stinging cells (radial symmetry)

Platyhelminthes

Flatworms; triploblastic, acoelomate, protostome, bilateral symmetry.

Nematoda

Roundworms; pseudocoelom, some cephalization and protostome some are parasitic.

Annelida

Segmented worms; coelomate, protostome, triploblastic.

Mollusca

Includes squid, snails; coelomate, bilateral symmetry, protostome

Arthropoda

Insects and crustaceans; segmented, coelom, protostome, cephalization, bilateral symmetry.

Echinodermata

Sea stars; bilateral symmetry as larvae, radial as adults, triploblastic, coelom, deuterostome

Chordata

Phylum with vertebrates; features dorsal nerve cord.

Triploblasts

Organisms with three germ layers: ectoderm, mesoderm, endoderm.

Cephalization

Having a concentration of sense organs and nervous system control; Having a head!

Protostome

Mouth develops first; Includes Arthropods, Mollusks, Annelids, Platyhelminthes, Nematodes

Deuterostome

Anus develops first/mouth second; Includes Chordates, Echinoderms

Diploblasts

Organisms with two tissue layers: ectoderm, endoderm. (only cnidarians)

Acoelomate

Organisms without a body cavity; e.g., flatworms.

Pseudocoelomate

Organisms with a body cavity not entirely mesoderm.

Endotherm

An organism that is internally warmed by a heat-generating metabolic process

Ectotherm

An animal whose body does not produce much internal heat

Vertebrata

Having a spinal column their entire life

Fishes

Non-amniotic egg, secrete ammonia, ectotherm, anapsid skulls

Amphibia

Non-amniotic egg, secrete urea, ectotherm, anapsid skull

Reptilia

Amniotic egg, secrete uric acid, ectotherm, majority have diapsid skulls (turtles are anapsid)

Birds

Amniotic egg, secrete uric acid, endotherm, diapsid skulls

Mammalia

Amniotic egg, secrete urea, endotherm, synapsid skull

Amniotic Egg

Protects eggs and provides greater food source

Homeotherm

Body temperature remains constant

Heterotherm

Body temperature fluctuates

Anapsid

No hole; Fish, amphibians, turtles

Diapsid

Two holes; Other reptiles, birds

Synapsid

One hole; Mammals

Eumetazoans

Organisms that have tissues

Symmetry

All triploblasts are bilateral with the exception of adult echinoderms

Body Cavity

A fluid-filled space separating the digestive tract from the outer body wall

Coelom

Derived from mesoderm, so only triploblastic animals can have it; Cushions internal organs; Allows internal organs to grow and move independently of each other