BY 124 1st Edition Lecture 12Outline of Last Lecture Chapter 33Coelomates (cont.)I. Phylum CrustaceaDeuterostomesI. Phylum BrachiopodaII. Phylum Echinodermata III. Phylum HemichordataChapter 34I. Phylum Chordataa. 4 key characteristics of all chordatesb. Subphylum CraniataOutline of Current Lecture Chapter 34 (cont.)I. 3 lineages of jawed vertebratesII. Tetrapodsa. Characteristicsb. Class Amphibiac. Class Reptiliad. Class AvesCurrent LectureChapter 34 (cont.)I. 3 lineages of jawed vertebrates:1. Chondrichthyans (sharks, rays, a. Skeleton composed of _____b. Most are predators These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.c. All vertebrates start off with a cartilaginous skeleton as embryoi. Retained even after reaching maturity in this classd. Traces of bone – scales, teethe. Have to swim to get oxygen that they needf. 3 different types if fins (dorsal, pectoral, and pelvic fins)g. No swim bladder(Came from early lungs in fish)i. Can’t stay at one depthh. Osmoregulate differently – have to keep high levels of urea in body i. This makes them more like freshwater fishi. Sharks have a ridge called a spinal valve that increases digestive surface areaj. Sharks have acute senses – can detect electrical fields of muscles from nearby animalsk. Internal fertilization but embryos develop differentlyi. Oviparous – eggs hatch outside motherii. Ovoviviparous – embryo develops within uterus and nourished by yolkiii. Viviparous – embryo develops within uterus and nourished through yolksac placenta from mother’s bloodl. Cloaca – where reproductive tract, excretory system and digestive tract empty2. Ray-finned fishes (Subclass Actinopterygii) a. “Actin” – rayb. Osteichthyans – bony endoskeletonc. “bony fish”d. Operculum – draws water over gillse. Swim bladder – controls buoyancyf. Lateral line systemg. Lay eggs/ external fertilizationh. Have 2 chambered heart (alright because they don’t have to worry about lungs)i. Ex. Sea horse, tuna, eelsj. Nostrils – do not use for breathing. Use for smell3. Lobe-finsa. Coelacanthsi. Thought to be extinct for 75 million yearsb. Lung fish – have a lung and can breathe airII. Tetrapods (4 legs)a. Characteristicsi. Four limbs with digitsii. Neck iii. Fusion of pelvic girdle to backboneiv. Absence of gills (except some aquatic species)v. Earsb. Class Amphibia1. “double life”2. 3 chambered hearts a. 2 atria and a ventriclei. Oxygenated and deoxygenated blood mixes in ventricle1. Okay because breathes across skin3. 1st vertebrates to come out on land4. Have to return to water due to external fertilization5. Came about during carboniferous period6. Metamorphosis (tadpole to frog)a. Tadpoles are herbivoresb. Adults are primarily carnivores (eat insects)ii. Order Urodela (salamanders)1. Can’t lift off ground very well/ stay close to ground2. Keep gills iii. Order Anura (frogs, toads)1. Toads have poison glands2. Some frogs do too (poison dart frogs)3. Some frogs will carry eggs on back and form skin over them4. Some have males carry them in their stomach until they hatchiv. Order Apoda (caecilians)1. “without legs”2. Like snakes ********Good diagram to study: Figure 34.2*********c. Class Reptilia1. Amniotes – have terrestrially adapted egga. Ex. Reptiles, birds and mammalsb. Amnion, chorion, yolk sac, and allantois – parts of “land egg”i. Amnion – enclose water around embryoii. Chorion – important for gas exchangeiii. Yolk – foodiv. Allantois – sac that keeps nitrogenous waste away from embryo2. Developed scales- helps with water loss3. Keratin4. Internal fertilization5. Have better lungs and limbs than amphibians6. 3 chambered heartsa. Crocodiles are exception and have 4 chambers7. Ectotherms – can’t regulate body temperature wella. Why they are not considered “real” land dwellersii. Tuataras1. Only 1 genus left2. Have a “3rd eye” on top off head that senses lightiii. Snakes1. Most snakes have fangsa. Coral snakes will chew you because they do not have good fangs2. Many modes of predationa. Constrictionb. Poison3. Poison has a hemotoxin and a neurotoxiniv. Turtles 1. Aquatic, terrestrial, and marine2. Temperature effects sex, not chromosomesv. Crocodilians1. Alligatora. Very protective2. Crocodile a. Most dangerous of crocodiliansb. Crocodile’s teeth show even when mouth is closedd. Class Aves (Birds)i. Feathers1. Keratin in feathers2. Came from scalesii. No urinary bladderiii. Only one ovaryiv. No teeth1. But have genes for teethv. Hollow bonesvi. Air sacsvii. Internal fertilizationviii. Some do not flyix. 4 chambered heartsx. Well-developed brain comparably but brain is mostly involved with instinctual stuff1. Have “fixed” patternsxi. Are not ectothermic – can regulate temperaturexii. Take care of babiesxiii. Sexual dimorphism1. Males and females look differentxiv. Age of birds – Jurassic