Lesson 8: Animal Kingdom

Invertebrate

Animal without backbone (97% of animal species)

Vertebrate

Animal with backbone (fish, amphibians, reptiles, birds, mammals)

Radial Symmetry

Body organized around central axis (e.g., jellyfish)

Bilateral Symmetry

Body with mirror-image left/right sides (e.g., humans)

Protostome

Embryonic development where mouth forms first (e.g., insects)

Deuterostome

Embryonic development where anus forms first (e.g., vertebrates)

Notochord

Flexible rod present in all chordate embryos

Tetrapod

Vertebrate with four limbs (amphibians, reptiles, birds, mammals)

Amniotic Egg

Shelled egg with protective membranes for land reproduction

Ectotherm

Animal relying on external heat sources (e.g., reptiles)

Endotherm

Animal generating own body heat (birds, mammals)