2 What characteristics do scientists use to classify animals? Scientists classify animals based on cell structure, how cells are organized into tissues, how tissues are organized into organs, and how organs are organized into systems.
3 What are Vertebrates?Vertebrates are animals that have backbones. The backbone helps an animal turn its body.
6 Groups of Fish Agnatha (Jawless Fish) – Have mouths of soft tissue with notrue teeth.Have no jaws or bonesSkeletons are made of cartilage (not bone)These fish do not have a true backbone, but they do have a tough nerve cord that runs down their back.They look more like bigworms than like fishLampreys, HagfishLampreyHayfish
7 Groups of Fish Chondrichthyes – Have jaws Sea RayChondrichthyes –Have jawsSkeletons are made of cartilage (not bone)The cartilage running down their backs is made of a chain of smaller parts called vertebraeHave paired finsSharks, sea raysWhale Shark - Chondrichthyes
8 Groups of Fish Osteichthyes (bony fish)– Have bones instead of cartilageHave fins that look like fans with spokes in themHave a movable flap over their gills that allows them to breathe while staying stillUnlike sharks, most bony fish have an organ called a swim bladder, or air sac, that allows them to hover at any depthMajority of fish fall in this groupCarp, sea horse, perch, etc.
10 Amphibians – Basic Facts Amphibian = “double life”Larvae (babies) live in water; adults live on landMost larvae are fishlike; adults are terrestrial carnivoresLarvae respire through skin/gills; Adults use lungsMost adult amphibians have four legs and moist skin that is not covered with scales
11 The Life Cycle of a Frog Adult Frog Fertilized Eggs Section 30-3Adult FrogFertilized EggsFrog eggs are laid in water andundergo external fertilization.The eggs hatch into tadpoles a few days to several weeks later.Young FrogTadpoles gradually grow limbs, lose theirtails and gills, and become meat-eaters as they develop into terrestrial adults.Tadpoles
12 and have special adaptations such as AmphibiansSection 30-3means“Double life”aslarvæ they live inadults they live onWaterLandand have special adaptations such asBonesLungsRibsarethat allow forthat allowthat provideEfficient movementBreathing airSupport and protectionare
13 Groups of Amphibians Salamanders – Long bodies and tails Adults are carnivorousUsually live in moist woodsFrogs and Toads –Lack tailsFrogs have long legs and are usually tied to waterToads have shorter legs and not as closely tied to waterCaecilians –Legless animals that burrow in moist soilHave fishlike scales
16 Reptiles – Basic Facts All reptiles have: Dry, scaly skin – helps prevent loss of body water in dry environmentsLeathery eggsBreathes through lungsCold-bloodedNorth American AlligatorNile CrocodileCoral Snake
17 Groups of Reptiles Lizards and Snakes Have legs & clawed toes (lizards) external ears, moveable eyelidsHighly evolved specialized forms (venom)Crocodiles and AlligatorsLong, typically broad snout and squat appearanceAll are carnivorousProtective of young; carry hatchlings in their mouthLive in tropics and subtropicsAlligators live in freshwaterCrocodiles live in fresh or saltwater
18 Groups of Reptiles (con.) Turtles and Tortoises –All are shelledTurtles are aquatic; tortoises are terrestrialTuatara –Primitive reptiles found on small, remote islandsGalapagos TortoiseSea TurtleTuatara
20 Birds – Basic Facts Nearly 10,000 modern bird species Birds are closely related to reptiles (scales on legs)Have feathers, two legs used for walking or perching, and forelimbs modified into wingsFeathers separate birds from all other animal speciesFeathers provide insulation for warmth; can generate on body heatBeak/Bills adapted to type of food they eatHighly efficient respiratory system; lungs only exposed to oxygen rich airLay eggs
21 have the following adaptations to flight Section 31-2Birdshave the following adaptations to flightWingsFeathersStrong chest musclesEfficient respiratory systemEfficient circulatory systemwhich arethat alsothat powerthat providethat ensureHomologous to front limbs in other vertebratesProvide warmthUpward and downward wing strokesOne-way flow of O2-rich airO2 distribution to body tissues