1. UNIT 8 Chapter 32: Introduction to Animal Evolution Chapter 33: Invertebrates Chapter 34: Vertebrate Evolution & Diversity

2. Organisms that belong in Kingdom Animalia must satisfy five requirements. 1. Animals are multicellular, eukaryotic and heterotrophic - Animals ingest preformed organic materials Features of Animals

3. 2. Animal cells lack cell walls - Multicellular bodies held together by extracellular proteins, especially collagen

4. 3. Animals have two unique tissue types: nervous and muscle - Nervous tissue involved with impulse (action potential) conduction - Muscle tissue for movement

5. 4. Most animals reproduce sexually and the diploid stage is dominant - In most species, a flagellated sperm fertilizes an egg - Cleavage commences: succession of mitotic divisions leading to the creation of a morula then ultimately a blastula

6. - Gastrulation creates the gastrula: a blind pouch with an opening called a blastopore - Some animals possess larval stage and undergo metamorphosis to become adult

7. 5. Development from zygote to animal depends on Hox genes (regulatory) - Hox genes regulate the expression of other genes - Ultimately involved with the fate of cells - Body form (anatomy)

8. 1. Tissues - Parazoans lack true tissues - Sponges are only extant parazoans Important Milestones in Animal Evolution

9. 2. Symmetry - Some animals possess radial symmetry, while others are bilateral - Most bilateral animals are cephalized: sensory organs at/in a head region

10. - the radiata are diploblastic (two germ layers) - ectoderm & endoderm - the bilateria are triploblastic (three germ layers) - ectoderm, endoderm & mesoderm

11. 3. Body Cavities - Acoelomates have no body cavity - Mesoderm isn’t lining digestive tract in pseudocoelomates - Coelomates have a body cavity and a digestive tract lined by the mesoderm

12. - a coelom has numerous functions: - fluid cushions internal organs - organs can move/grow independent of the body covering - can serve as a hydrostatic skeleton

13. 4. Protostomes vs. Deuterostomes Table 32.1 END

14. Within this phylum, there animals lacking backbones and animals possessing them. In either case, ALL chordates have four features. 1. Notochord 2. Dorsal, hollow nerve cord 3. Pharyngeal gill slits 4. Post-anal tail In order to be a “member” of Phylum Chordata, you must have exhibited each of these characteristics at some point in your development.

15. Notochord: flexible rod that runs longitudinally through the animal comprised of fluid-filled cells, encased in fibrous tissue provides skeletal support in some, notochord is reduced in adult ex. It’s the “disc” material in human vertebrae

16. Dorsal, hollow nerve cord: nervous tissue that develops from the embryonic ectoderm. most non-chordates have a solid, ventrally located, nerve cord becomes the CNS in vertebrates

17. Pharyngeal gill slits: connect the animal’s pharynx to the outside. allows water to enter the animal’s mouth and exit without entering the digestive system used/modified in various ways: feeding, respiration

18. Post-anal tail: muscular in most chordates and extends past the anus compare to non-chordates that have a full body- length digestive system contains skeletal and muscular elements used for propulsion in many aquatic species

19. Invertebrate chordates

20. Class Amphibia Undergo a metamorphosis from a swimming larval tadpole stage to a terrestrial adult. Even though adult amphibians are terrestrial, they cannot venture far from water. respiration eggs would desiccate

21. Amphibians usually similar anatomy to other vertebrate chordates Huge difference is that their heart is three- chambered (one ventricle, two atria)

22. Class Reptilia Success is due to the amniotic egg Extraembryonic membranes provide structures involved with gas exchange, waste storage, and nutrient storage Desiccation is prevented

23. Reptiles are referred to as ectotherms Do not use metabolism to heat bodies Compare to endotherms

24. Four-chambered heart first appears in some reptiles TOTAL separation of oxygenated and deoxygenated blood Scales rather than skin

25. Class Aves Almost every aspect of a bird’s anatomy is adapted for flight, including its feathers Feathers, made of keratin, are very light and strong

26. Class Mammalia Mammals are distinguished by the presence of mammary glands which produce milk to nourish young MOST (almost all) have hair made of keratin Most are born (not hatched) and possess relatively large brains making them capable of learning

27. 1. Monotremes – reptile-like egg, no nipples (platypuses and echidnas) 2. Marsupials – born “early” and completes development in the mother’s pouch (kangaroos, koalas, etc.) 3. Eutherians – development “completed” in placenta in mother END