Animals

1. Animals • heterotrophs • multicellular • lack cell walls • move from place to place • most reproduce _________ • characteristic pattern of ___________ • possess unique tissues

2. Symmetry-embryonic layers • lack of symmetry: • Sponges • Radial : • body arranged around a central axis • cnidarians • _____ embryonic layers • outerectoderm= epidermis • inner endoderm= gastrodermis • bilateral: • body has left and right mirror images • _____________ • ____ embryonic layers • Ectoderm= epidermis • Endoderm=gastrodermis • Mesoderm= skeleton, muscles

3. Body Cavity • Improves the animal body design: • Circulation: fluids that move • Movement: fluid makes the animal’s body rigid permitting resistance to muscle contraction • organ function: organs function without being deformed by surrounding muscles • Bilateral animals: • Acoelomate: no cavity • Pseudocoelomate: cavitybetween mesoderm- endoderm • Coelomate: cavity within the mesoderm

4. Segmentation • building of a body from a ________ of similar segments • a small change produces a new kind of segment with a different __________

5. Embrynic development • cell divisions of the fertilized egg: • Compact ball of cells: __________ • hollow ball of cells: _______ • Indentation of the blastula: blastopore= opening to the outside • protostomes, mouth develops from the blastopore • deuterostomes, anus develops from the blastopore, mouth from other part of the blastula

6. Sponges • Porifera • lack tissue/organs • masses of specialized cells embedded in a gel-like matrix • perforated by tiny holes • flagellated cells line the body cavity and draw water in through the pores: ______________

7. Cnidaria • Ex: jellyfish, hydra, corals, sea anemones • radial symmetry • extracellular digestion: digestion outside of cells in a gut cavity • ___________: capture their prey with tentacles • 2 basic body forms • Medusae: free-floating • Polyps: sessile Jellyfish Sea anenome

8. Flat worm • platyhelminthes • simplest bilateral animals • lack internal cavity • digestive cavity only has one opening: cannot _________________________ • lack circulatory system, thin-bodies= diffusion • Reproduction: • hermaphroditic • asexual regeneration

9. Round worms • Nematoda • hydrostatic skeleton: muscles work against the fluid • unsegmented worms • cylindrical body • Ex: • genetic and development studies: Caenorhabditis elegans • parasites: • Trichinella:trichinosis= consuming undercooked pork • Heartworm (dogs) • Ascaris lumbricoides: intestines

10. Hollow worms: annelids • Ex: Earthworm, leeches • A tube __________________ • repeated segments, excretory and locomotor organs are repeated • Specialized anterior segments contain sensory organs and brain • circulatory and nervous system

11. Mollusks • _________ (with real cavitites) • without segmented bodies • basic body design • foot: muscular structure • central visceral mass: body’s organs • mantle: surrounds the visceral mass • radula, arasping tongue-like organ • ________ formed (clams, oysters) when foreign objects are lodged between mantle-inner shell, the mantle coats the foreign object with layer upon layer of shell material to reduce irritation

12. Gastropods: snail • foot to crawl, mantle for protection • __________________ • Bivalves: clam • two-part shell with a hinge • filter-feed by drawing water into their shell • Cephalopods: octopus • modified mantle cavity that permits ____________ • shell is reduced or absent

13. Arthropods • Biggest group, most successful! • _____________: • surrounds body for protection • and keeps water in • Molt • ___________ symmetry • Complex organs system! sensory, respiratory, social behavior • divisions: crustacean, millipede (and centipede), arachnids, insects

14. Echinoderms • first deuterostomes • spiny skin=endoskeleton • Larva is __________but adult ______ • water vascular system: fluid-filled canals that extend into numerous hollow tube-feet for locomotion

15. Chordates • Deuterostome: coelomates • large animals • ________, flexible rod beneath the nerve cord in the early embryo • _______, dorsal hollow nerve cord • postanal tail, a tail that extends beyond the anus, at least during embryonic development • Vertebrates • backbone (series of hollow bones) that replaces the notochord • Head: skull and brain

16. Fish • Gills, to extract dissolved oxygen ________ • vertebral column, skeleton made of either bone or cartilage • single-loop blood _________ , blood is pumped from the heart to the gills, to the body, and then back to the heart • Types:

17. Chondrichthyes • Ex: sharks and rays • first jawed fishes • flexible, cartilaginous skeleton • Bony fish • internal skeleton of bone • _____ ______, gas-filled sac to regulate buoyant density • most diverse of all vertebrates

18. Amphibians • direct descendant of fishes • Ex: Frogs, Salamanders • Moist skin for __________ • Legs • Lungs and cutaneous respiration • pulmonary veins, returns oxygenated blood from the lungs to the heart for repumping • partially _______ heart, helps to prevent oxygenated blood deoxygenated blood

19. Reptiles • Ex: Turtles, lizards, snakes, crocodile, alligators • amniotic egg: watertight eggs protected from drying out with food source (yolk) comprised of four layers of membranes • Chorion: O2 to enter but not the exit of H2O • yolk sac:connects to the gut of the embryo and delivers food • Allantois:accumulates wastes from the embryo • Amnion: fluid-filled • dry skin to prevent ________ ________

20. Birds • evolved from bipedal dinosaurs • lack teeth • vestigial tails • _________ eggs • reptilian scales on their feet and lower legs • ____________ lightweight and adapted for flight • flight skeleton is firm for attaching flight muscles, the bones are thin and hollow

21. Mammals • middle ear with three bones that evolved from bones in the reptile jaw • _____________________ in females to produce milk to nurse the newborns • _________________ to provide nourishment to the young while it is in the uterus • Endothermy which allows mammals to be active at any time of the day or night and to ___________________ • Heterodont dentition, different types of teeth are highly specialized to match eating habits • Hair for insulation made up of dead cells filled with the protein, keratin • horns, claws, fingenails made with keratin

22. monotremes, • the only egg-laying mammals • Ex: duck-billed platypus and anteater 2. marsupials, • young nursed in a marsupial pouch • Ex: __________ 3. placental mammals, • young develop in the uterus for a long time while being nourished by a placenta • Ex:

23. Practice questions • Which of the following characteristics is not seen in the flatworms? • Cephalization • Mesoderm • specialization of digestive tract • bilateral symmetry 2. One difference between Nematoda (roundworms) and Annelida (segmented worms) is the pseudocoel develops between the mesoderm and the _____________ in roundworms, and the coelom develops in the _____________ in segmented worms.

24. 3. All fish species share all of the following characteristics except: • Gills • Jaws • endoskeleton with dorsal nerve cord • single loop circulatory system. 4. sharks and bony fish have evolved anatomical solutions to increase swimming speed and maneuverability. Which of the MAJOR modification found in bony fish? ___________ • Adaptations in reptiles that allow them to overcome dehydration include ______, _________ • Characteristics that evolved in birds to allow for flight include ________ AND _______ • A characteristic unique to almost all mammals and no other vertebrates is ___________