BIOL 112 1st Edition Final Exam Study Guide Lectures 34 39 Study previous tests for the earlier material Some questions will come straight from previous exams Lecture 34 November 21 Ancestral deuterostome echinoderms and chordates sister taxa Chordate characteristics always present in embryos not always in adults Notochord flexible dorsal rod Endoskeleton works with muscles Dorsal hollow nerve chord tube forms from folded ectoderm above the notochord Pharyngeal slits Clefts Ancestral use for filter feeding and gas exchange Sea mouth pharynx slits sea Muscular post anal tail Multiple muscle segments for undulating locomotion Invertebrates Cephalochordata lancelets All key chordate features in adults Burrows for suspension feeding Urochordata tunicates sea squirts Highly developed sessile adults Suspension feeders with pharyngeal slits Tough cellulose tunic Only adult chordate characteristic is pharynx with slits larval stage has all characteristics Incurrent and excurrent siphons Vertebrates Vertebrae of cartilage or bone Encloses dorsal verve chord spinal chord Vertebral column replaces notochord as main body support in most vertebrates allows for larger body size Well developed head Cranium skull of bone or cartilage Remnants are disks Holds brain coordination of voluntary and involuntary movement Paired sensory organs 1st vertebrates didn t have jaws or teeth Efficient circulatory system with a heart Closed circulatory system 2 4 chambers with valves Hemoglobin in blood cells Gill arches rods of cartilage bone support gill slits Arteriole capillary bed artery vein venule atrium ventricle Muscle action helps ventilate gills Earliest vertebrates All jawless and fish like Many later jawless fish had bony armor plates Some with lateral fins All extinct by mid Paleozoic replaced by jawed fish Jawless Vertebrates Myxini hagfish Marine scavengers Reduced eyes Defensive slime Petromyzontida lampreys Jawless parasite on fish Spinal cartilage elements Keratin teeth Lecture 35 November 24 Gnathostomes having a jaw Jaws derived from gill slit supports Teeth derived from scales Large forebrain smell and sight Paired lateral fins limbs Aquatic adaptations Lateral line system detects pressure waves from enemy prey Filamentous gills use countercurrent exchange for more oxygen in the blood Blood flows in the opposite direction of water for max oxygen diffusion Large surface area Fish are a paraphyletic group Cartilaginous fish are basal Gnathostomes Condricthyes sharks rays and skates Skeleton of cartilage Buoyancy controlled by liver oils active swimming and a less dense skeleton Osmoregulation and water balance Water intake mostly from food Retains urea in tissues Isotonic with seawater salt concentration is less in tissues than seawater expels excess salt by the kidneys in the feces Internal fertilization Varied development Oviparous egg is laid and the embryo develops inside the egg with a yolk Ovoviviparous egg retained in the mother and fed by yolk live birth Viviparous embryo fed directly by mother s tissue live birth Marine active predators Spiral valve increases surface area for digestion and absorption Lecture 36 December 1 Osteichthyes bony fish Paraphyletic omits tetrapods Aquatic gnathostomes with ossified calcium phosphate skeleton Flat scales with slime for protection and drag reduction Operculum protects and pumps water over gills Lungs From out pockets of the esophagus Swallows air in oxygen poor freshwater for gas exchange Modified to a swim bladder for most fish for low energy buoyancy Osmoregulation Marine Active transport ions from gills Kidneys excrete little urine Fresh water Active transport of ions into gills Lots of dilute urine External fertilization Oviparous Protected only by jelly Actinopterygii ray finned fish diverse Thin fins supported by long flexible rays Marine and fresh water Sarcopterygii lobe finned fish Pelvic and pectoral fins supported with muscles and bones Ex coelacanths Actinista lungfish Dipnoi Tetrapods 4 limbs with wrists and digits Pelvic girdle fused to backbone Neck Lung breathing as adults Tiktaalik and Acanthostega Fish scales fins gills and lungs Tetrapod eyes on top of the head neck flat skull Amphibians Most basal extant tetrapods Thin moist skin for gas exchange loses water Gulping lungs also for gas exchange 3 chambered heart Dual circulation increases blood pressure better oxygen supply Reproduction closely tied to water mostly oviparous Larval stage aquatic with gills metamorphosis carnivorous adults 3 orders Salamanders 4 legs tail Frogs and toads 4 legs no tail Caecilians no legs Lecture 37 December 3 Amniotes egg useful for dry environments free from water Embryo enclosed in amniotic sac Amnion cushions embryo Albumen stores water Yolk stores and delivers nutrients Chorion for gas exchange Allantois for waste disposal Porous egg shell protects and reduces water loss Allows for gas exchange Rigidity depends on amount of calcium carbonate Fertilization must be internal Shell is absent in most mammals Waterproof Skin Layers of dead cells with keratin and lipids No gas exchange across skin Water conserving Excretion of Nitrogenous Waste Fish ammonia Mammals and Sharks urea Many birds reptiles uric acid costs the most energy but conserves the most water Breathe by Expanding Rib Cage Efficient negative pressure breathing Fish and amphibians have to gulp air Improved dual circulation Separate reptiles or completely divided birds and mammals ventricles Control of Body Temperature Ectothermic use environment to warm body Behavioral thermoregulation basking Low metabolic rates generate little heat All non bird reptiles Endothermic high metabolic rate generates heat and warms body Physiological thermoregulation Birds and mammals Requires insulation fat fur or feathers Reptiles Turtles basal Archosaurs crocs dinos and birds Lepidosaurs tuataras lizards and snakes Non bird Reptiles Scaly skin without fur or feathers Sprawling stance low profile Low metabolic rate ectothermic Leathery less calcified egg shells Uric acid metabolic waste excreted through cloaca also for birds Turtles Upper and lower bony shells fused to ribs and vertebrae Covered by keratinous scales Keratin beak replaces teeth Land fresh water and marine Always lays eggs on land Lepidosaurs Tuataras Ancient lizard like reptile No external ears Light sensitive pineal gland on top of head 3 rd eye Lepidosaurs Lizards and Snakes Most lizards are terrestrial predators All snakes are