1. Chapter 25- Intro to Animals

2. I. Characteristics A. Kingdom Anamalia 1. Multicellular 2. heterotrophic 3. eukaryotic 4. lack cell walls

3. B. Types of Animals 1. Invertebrates a. Includes all animals that lack a backbone or vertebral column b. Sea stars, worms, jellyfish, squid, insects c. 33 phyla

4. 2. Chordates a. Less than 5% b. Phylum Chordata c. 4 common characteristics that must be present sometime in life- pg. 731 » Hollow dorsal nerve cord » Notochord- long supporting rod that runs under the nerve cord » A tail that extends beyond the anus » Pharyngeal pouches- structures in the throat region d. Chordates with backbones are called vertebrates » fish, amphibians, reptiles, birds, mammals

5. C. Survival in the Animal Kingdom 1. All animals have the ability to maintain homeostasis a. Use the nervous system to gather & sense information, interpret the information and stimulate muscles to respond b. Maintain and distribute oxygen & nutrients (respiratory, circulatory & digestive systems all work together) c. Eliminate carbon dioxide & waste d. Reproduce e. Maintained by feedback inhibition or negative feedback

6. II. Body Plan A. Symmetry 1. Radial symmetry- many planes of symmetry (circle) 2. Bilateral symmetry a. most successful b. 1 plane of symmetry c. Definite front and back side, & head and tail end 3. Asymmetry – no plane of symmetry

8. B. Germ layers 1. Endoderm a. Inner most layer b. Lines the digestive tract & respiratory system 2. Mesoderm a. Middle layer b. Gives rise to the muscles and the circulatory, reproductive & excretory system 3. Ectoderm a. Outer most layer b. Produces sense organs, nerves and outer layer of skin

9. C. Body Cavity- pg. 738 1. Coelomates a. Have a true coelom – a body cavity that develops within mesoderm tissue and is completely lined b. Example: earthworm 2. Pseudocoelomates a. Have a pseudocoelom- partially lined body cavity b. Example: roundworm 3. Acoelomate a. No body cavity b. Example: flat worm

11. D. Patterns of Embryological development 1. Fertilized egg is a zygote 2. As the zygote grows during mitosis, it develops into a structure called a blastula 3. As the digestive tract forms in the blastula, there is initially a single opening called a blastopore 4. If the organism is a protostome, the blastopore becomes the mouth 5. If the organism is a deuterostome, the blastopore becomes the anus

13. E. Segmentation 1. Body parts that are repeated in animals with bilateral symmetry 2. Ex. Segments of the earthworm, vertebrae in humans

14. F. Cephalization: getting a head 1. Animals with bilateral symmetry usually have a head 2. This happens when the concentration of sense organs and nerve cells increase at the anterior end 3. Animals usually move “head first”

15. G. Limb Formation 1. External appendages that are jointed 2. Ex. Wings, flippers, arms, leg

16. III. Invertebrate & vertebrate Phyla

17. Phylum Porifera – Specialized cells – Asymmetrical – No germ layers – No body cavity – No segmentation – No head – Sponges are the most ancient members of the animal kingdom

18. Phylum Cnidaria – Specialized cells, tissues, specialized stinging cells – Radial Symmetry – 2 germ layers – Acoelom – No segmentation – No head – Hydras, coral, jellyfish, sea fans, sea anemones

19. Phylum Platyhelminthes – Specialized cells, tissues, organs – Bilateral symmetry – 3 germ layers – Acoelom – Protostome – No segmentation – Cephalization – Flatworms

20. Phylum Nematoda – Specialized cell, tissues, organs – Bilateral symmetry – 3 germ layers – Pseudocoelom – Protostome – No segmentation – Cephalization – Round worms

21. Phylum Annelida – Specialized cells, tissues, organs – Bilateral symmetry – 3 germ layers – True coelom – Protostome – Segmentation present – Cephalization – Earthworms, leeches, marine worms

22. Phylum Mollusca – Specialized cells, tissues, organs – Bilateral symmetry – 3 germ layers – True coelom – Protostome, motile larval stage called a trochophore – No segmentation – Cephalization – Snails, slugs, clams, squid, octopi

23. Phylum Arthropoda – Specialized cells, tissues, organs – Bilateral symmetry – 3 germ layers – True coelom – Protostome – Segmentation present, jointed appendages – Cephalization – Insects, spiders, centipedes, crustaceans

24. Phylum Echinodermata – Specialized cells, tissues, organs – 5 part radial symmetry (as adults) – 3 germ layers – True coelom – Deuterostome – No segmentation – Cephalization absent (as adults) – Sea star, sea urchins, sand dollars

25. Phylum Chordata – Specialized cells, tissues, organs – Bilateral symmetry – 3 germ layers – True coelom – Deuterostome – Segmentation present – Cephalization – Tunicates, lancelets, vertebrates