Chapter 23

Invertebrate Diversity

23.2 Animal Diversity

Animal: multicellular, eukaryotic, heterotroph (by ingestion) whose cells lack cell walls Each animal phylum has a unique

body plan. Invertebrates: no back bone Vertebrates: have back bones More than 95 percent of all animal

species are invertebrates.

23.2 Animal Diversity

Survival 1. Feeding: how animals eat 2. Respiration: how animals get

O2 and give off CO2

3. Internal Transport: how animals move O2, nutrients, and wastes around body

4. Excretion: how animals get rid of waste

23.2 Animal Diversity 5. Response: how animals sense

and respond to their environment 6. Movement: how animals move

using muscles and a skeletal system

7. Reproduction: how animals keep their species alive

23.2 Animal Diversity

Symmetry radial: many planes of symmetry

along one axis bilateral: one plane of symmetry

Radial

Bilateral

Asymmetrical