1. Introduction to the Animal Kingdom

2. Introduction to the Animal Kingdom Animals are multicellular eukaryotic heterotroph whose cells lack cell walls Vertebrates: 5% of animal species with backbones Invertebrates: 95% of animal species WITHOUT backbones Cell specialization – special shape, physical structure, and chemical composition to perform a special function in a multicellular organism (Division of Labor)

3. In Order to Survive, Animals Must: Feed – –Carnivores – eat other animals –Herbivores – eat plants –Omnivores – eat other animals and plants –Parasites – inside or on other organisms and do them harm –Filter feeders – strain food from water –Detritus feeders – feed on dead organic matter

4. In Order to Survive, Animals Must: Respire – –Consume oxygen and give off CO2 –Skin, gills, lungs

5. In Order to Survive, Animals Must: Circulate/Internal Transport – –Must carry O2, nutrients and waste products to and from internal cells –Heart and blood vessels in larger animals –Smaller animals rely on diffusion

6. In Order to Survive, Animals Must: Excrete – –Small animals – diffusion –Larger animals – excretory systems (that can include complex kidneys)

7. In Order to Survive, Animals Must: Respond – –Nerve cells – brain –Gather information from environment –Varies greatly from phylum to phylum

8. In Order to Survive, Animals Must: Move – –Sessile – one spot, no movement –Motile – move, muscles and/or skeletons

9. In Order to Survive, Animals Must: Reproduce – –Mainly sexual, but invertebrates can also reproduce asexually –Live birth or eggs –Direct Metamorphosis – young look like adult –Indirect Metamorphosis – young → metamorphosis → adult

10. Direct Metamorphosis –Direct – young look like adult

11. Indirect Metamorphosis Indirect – young → metamorphosis → adult

12. Animal Evolution Complex animals tend to have high levels of cell specialization and internal body organization, bilateral body symmetry, a front end, or head, with sense organs, and a body cavity.

13. Cell Specialization Cell → tissue → organ → organ system → organism –Ex. Stomach cell → stomach tissue → digestive system (mouth, stomach, intestines, etc) → all organ systems put together

14. Early Development Zygote (fertilized egg) undergoes divisions to form blastula, or a hollow ball of cells Blastula flattens on one side and folds into itself forming a single opening called a blastopore Blastopore leads into center tube running the length of the developing embryo. This tube becomes the digestive track –Protostome – mouth formed first from blastopore (most invertebrates) –Deuterostome – anus formed first from blastopore (echinoderms and all vertebrates)

15. Early Development (continued) Cells then differentiate into three layers, called germ layers –Endoderm – innermost germ layer – forms linings of digestive track and respiratory system –Mesoderm – middle germ layer – forms muscles, circulatory, reproductive, and excretory systems –Ectoderm – outermost germ layer – forms sense organs, nerves, and outer layer of skin

16. Early Development (continued)

17. Body Symmetry Asymmetrical – no symmetry (sponges) Radial symmetry – body parts repeat around center of body (simple animals – sea anemone and starfish) Bilateral symmetry – body can be divided into two equal halves – left and right sides –Anterior – front end –Posterior – back end –Dorsal – upper side –Ventral – lower side

18. Body Symmetry Radial Symmetry Bilateral Symmetry Planes of symmetry Plane of symmetry Dorsal side Posterior end Anterior end

19. Cephalization Complex animals concentrate sense organs and nerve cells in the anterior end of the body, this is called cephalization –Ganglia – small clusters of nerve cells (simple animals) –Brain – clusters of ganglia (more complex animals)

20. Introduction to Invertebrates