Dr. Yost - Exam 1 Lecture Notes - Chapter 32 PDF

Preview

Summary

Dr. Robert Yost lecture notes for exam 1 of BIOL-K 103. These notes provide exact details as to what material is present on his exams. The book is unnecessary to purchase. He never changes his exams. ...

Description

Chapter 32: The Deuterostomes See note with previous chapters. After reading the associated assignment in the textbook, attending lecture, and/ or attending the accompanying laboratory and recitation, you should be able to: 1. Review protostome and deuterostome development (knowledge/comprehension) [see earlier cladogram for this] 2. Name and describe the ancestral features and the derived features leading to echinoderms, chordates and vertebrates. Name the four major phyla of Deuterstomes. (knowledge/comprehension 3. Name and describe the general characteristics of echinoderms (knowledge/comprehension) 4. Name, compare and contrast the major classes of echinoderms. (knowledge/comprehension) 5. Name and describe the shared derived features of chordates and vertebrates (knowledge/comprehension) 6. Compare and summarize the characteristics of the invertebrate Subphyla Urochordata and Cephalochordata in Phylum Chordata (knowledge/comprehension) 7. Review the vertebrate cladogram and distinguish between craniates, vertebrate, tetrapod, and amniote groups and name the classes in each (knowledge/comprehension) 8. Name, describe the major features and give examples of the living clades of vertebrates [classes, orders and other taxa as discussed in class – see cladogram above.] (knowledge/comprehension) Note: This objective will apply on all sections related to vertebrates. 9. Define and give examples of oviparous, viviparous and ovoviviparous animals (knowledge/comprehension) 10. Compare and contrast ray-finned and lobe-finned fish (knowledge/comprehension) 11. Describe how land dwelling tetrapods evolved from lobe-finned fishes (knowledge/comprehension) 12. Compare and contrast the two clades of modern birds (knowledge/comprehension) 13. Compare and contrast the derived features and general features of mammals, including protherian (monotremes), metatherian (marsupials), and eutherian mammals (knowledge/comprehension/analysis)

Some New Words Adaptive radiation formation of many new species from an ancestral species, often occurs rapidly in geological time when a new niche opens up Arboreal living in the trees Cloaca common exit point shared by reproductive, excretory and digestive systems (literal translation is sewer) Desiccate dry out from lack of water (hydration) Ectothermic animal whose body heat goes up and down with changes in the external environmental temperature, “cold blooded” Endothermic animal whose body heat is maintained independent of the external temperature Eutheria animals that nourish the embryo via a placenta Metamorphosis undergo a change in body form from one developmental stage to another Metatheria animals that raise their young in a pouch (e.g. kangaroos) Oviparous animals that lay eggs and embryo is nourished by the yolk Ovoviviparous animals that incubate an egg internally,embryo gets nourishment from the yolk, and have live births Protheria egg laying mammals (e.g. duckbilled platypus) Viviparous animals where the young develop inside the uterus and nutrients are transferred from mother to embryo

Chapter 32: The Animal Kingdom: The Deuterostomes

Objective 1: Review protostome and deuterostome development (knowledge/comprehension) [See earlier cladogram and discussion for this too.] Slide 33

Ancestral features Deuterstomes Multicellularity Tissues (three tissue layers) Triploblastic Bilateral symmetry True coelom (coelomates) Deuterostomic development Other features vary with phylum and class Phylum Echinodermata and Phylum Chordata Notice segmentation revolved in chordates

Note: Endostyle is ciliated groove in urochordates and cephalochordates and lamprey larva. It is involved in transporting food to the esophagus. This region is the thyroid gland in vertebrates. Phylum Echinodermata - starfish Habitat: marine Water-vascular system  derived and defining characteristic  feeding, gas exchange, hydrostatic skelton Madreporite Stone canal Ring canal Ampullae Tube feet

Symmetry Bilateral: larval Pentaradial in adults Body surfaces Oral surface Aboral surface

Major echinoderm classes 1. Asteroidea: sea stars 2. Crinoidea: sea lilies and feather starts 3. Echinoidea: sea urchins and sand dollars Body: round, flat, no arms Skeleton:

Note: Endostyle is ciliated groove in urochordates and cephalochordates and lamprey larva. It is involved in transporting food to the esophagus. This region is the thyroid gland in vertebrates.

Deuterostomes Phylum Chordata Invertebrate subphyla

Subphylum Urochordata (invertebrate chordates) Tunicates (sea squirts and relatives) Body covering  carbohydrate tunic with openings for siphons Chordate features Larva  all chordate features  swims Adult  gill slits  sessile Feeding - suspension feeders

Subphylum Cephalochordata (invertebrate chordate) Body plan  adult- all four chordate features  no paired fins, jaws, sense organs, heart, head or brain Feeding  filter feeders Genus Branchiostoma: gill plus mouth originally Amphioxous: sharp on both sides

Note: Hagfish have partial cranium so are included in craniates but they lack vertebrae and are not usually considered to be a member of the vertebrate group. They are in this figure from the book. Use this cladogram and the chordate cladogram above as reference for the vertebrate discussions.

Chordates Distinguishing features of vertebrates A. Vertebral column (cartilage or bone) B. Pronounced cephalization C. Brain (in cranium) D. Neural crest cells (influence development of many structures including melanocytes, smooth muscle, nerves and craniofacial cartilage) E. Hox gene clusters (involved in the regulation of development; code for transcription factors) F. Systems 1. Circulatory system 2. Digestive system 3. Endocrine system 4. Endoskeleton 5. Excretory system

Note: Ten extant (living) classes of vertebrates, 6 of which are fish and 4 are tetrapods

Solomon 10th edition

Solomon 10th edition

Slide 40

Chordates Jawless Fish Craniate jawless fish (nonvertebrate) Hagfish – (Class Myxini) [Craniate but not in vertebrates.] Habitat o marine Body Cranium o cartilage and incomplete (not fulling calcified or enclosing) Teeth o keratin and on tongue Notochord o flexible cartilage o only craniate with no vertebrae of any kind Fins o long fin fold along dorsal side

Feeding  scavengers Defense  secretes slime – covers gills of attacking fish o fish retreat or may die from lack of oxygen o will sneeze if own slime blocks breathing Body tonicity  only craniate isosmotic with salt water

Craniate Jawless fish Lampreys (Class Pteromyzontida) Oldest living vertebrate lineage Habitat  marine, freshwater, estuaries Lifestyle  parasites Vertebral column Primitive  cartilage rod next to notochord with extensions  similar to vertebrae that partially enclose nerve cord  Craniate – has cranial cartilage

Jawed Fish Cartilagenous fish (Class Chondrichthyes) Jawed fish Members include skates, rays, and sharks Habitat  Mostly marine (some freshwater skates) Body Skeleton and cranium  Cartilage infused with calcium salts Teeth  Replaceable  Modified scales Scales  Placoid (tooth like) and nonoverlapping Fins  paired Mouth  ventral Gill openings  lateral in sharks  ventral in skates and rays Senses Brain: well developed Nostrils: blind ended - olfaction Electroreceptors: detect prey Lateral line system: detect vibrations in water Cloaca  common opening to outside for reproductive, excretory, and digestive systems (also birds and amphibians) Clasper  males use to transfer sperm into female cloaca Body density  would cause them to sink when not swimming  fat composition of liver keeps them afloat swimming

Vertebrate Modes of Reproduction Oviparous  lay eggs, nourishment from yolk  example: skates, some sharks, birds, reptiles, fish Ovoviparous  eggs incubated inside mother, nourishment from yolk  examples: many sharks, snakes, fish, snakes Viviparous  embryos develop within uterus  nutrients transferred from maternal blood vessels to embryo  examples: some sharks, most mammals, humans Chordates Bony fish (Class Osteichthyes) Jawed fish Habitat  marine and freshwater Body Skeleton and cranium  calcified Teeth  replicable Scales  overlapping and flexible  origin dermal bone Fins  paired  supported by cartilage or bone Mouth  anteriorly directed Gills  internal  covered by operculum Swim bladder  buoyancy (gas exchange in some) Reproduction  most oviparous (external fertilization) Ray finned bony fish  most fish  rays of cartilage or bone run length of fin

Lobe-finned fish bony fish  some use lungs instead of gills  gave rise to land dwelling tetrapods  fleshy with bones at base  rays evolved into phalanges  mitochondrial DNA indicates connection to tetrapod land dwellers

Chordates Tetrapods – four appendages Class Amphibia Definition  having two lives -water/land  reproduce - water Metamorphosis  many complete  some, like salamanders, retain main larval characteristics Some show paedomorphosis Respiratory organ  Lungs, gills, or skin (must stay moist) Heart  3 chambers (2 atria & 1 ventricle) Amphibian orders (3) Urodela (or Caudata) [“visible tail”] – tail as adult  Salamanders, mud puppies, and newts A-nura [“no tail”]  Frogs and toads A-poda [“no feet”]  Wormlike caecilian (internal fertilization)

Amniotes are terrestrial vertebrates. Transiton to land required evolution of an aminote egg

Chordates: Reptiles Class Reptilia Shelled egg [move onto land]  Body surface [move onto land]  Hard scales – water tight Respiration  Lungs divided into many chambers Circulation (Heart)  3 chambered heart separates oxygen-rich and oxygen-poor blood Sense organs  Well-developed to locate prey Ectotherms – “cold-blooded”  Body temperature changes with surrounding environment Four orders of reptiles (class Reptilia) Testudines (turtles, terrapins, tortoises) Squamata (lizards, snakes, worm lizards) Crocodilia (crocodiles, alligators, caimans, gavials) Sphenodonta (tuataras only) Superorder Archosauria extant order Crocodilia, and Aves (birds)

Chordates Class Reptilia Order Testudine (turtles, terrapins, tortoises) Shell : bondy plates overlaid by horny scales Carapac: top, dorsal Plasteron: bottom, ventral – can tell male and female Skeleton Vertebrae and ribs: fused to shell Pelvic and pectoral girdles: lie inside of the ribs Mouth (jaws): jaws covered by horny beak, no teeth

Turtles - water Tortoises - land Terrapins – (fresh water)

Class Reptilia Order Squamata (lizards, snakes, worm lizards) Some legless tetrapods o Snakes and worm lizards Komodo dragon o Close relative of snakes o Most infectious bite in the world Snakes Jaws o Loosely articulated Skin o Elastic o Combined makes it possible to swallow large prey Tongue o Sensory organ for touch and smell Pit organ (in vipers) o Detects heat from endothermic prey Ecdysis (molt) – even as adults Class Reptilia Order Crocodilia (crocodiles, alligators, caimans, gavials) Most live in swamps, in rivers, or along seacoasts Feeding on various kinds of animals

Crocodiles have a long, slender snout and a large, visible bottom tooth Crocodiles are the largest living reptiles Crocodilians have four chambered heart (later) in all All are good divers

Supraorder Archosauria - crocodiles (order Crocodilia - above) and birds (class Aves – below) Theropod bipedal dinosaur group - gave rise to birds

Palaeognaths Flightless: birds such as ostriches, kiwis, cassowaries, and emus Flat sternum: no ridge for attachment of wing muscles Vestigial Wings Legs: well-developed for running Neognaths Most fly Keeled sternum: attachment of flight muscles Wings: most well adapted for flight, penguins use strong pectoral muscles, small flipper like wings to swim Toes: three facing forward and one back Passerine: toe positions adapted for perching

Characteristics of Modern Birds Class Aves (modern birds) Reproduction: lay eggs Scales: legs with scales Feathers: derived from scales Endothermic: share with mammals Nitrogenous waste: uric acid – solid/semisolid – doesn’t really have to drink a lot Respiration: lungs with air sacs (one-way air flow) Heart: 4 chambered Bills: adapted for specific types of foods Digestive system Crop: food storage Gizzard: muscular, food grinding Chordates Class Mammalia Derived features Hair Mammary glands Tooth differentiation Incisors, canines, premolars, molars One pair of openings in temporal bone

Middle-ear bones  Only one in reptiles and birds [mammalian stapes]  Mammals have three – malleus, incus, and stapes Changes in cochlea  Further evolved in mammals providing more sensitivity in high frequency  Exception – barn owl can hear upper frequency As many reptiles became extinct, mammals underwent an adaptive radiation

Other features making mammals successful Cerebrum large and complex specialized cerebral cortex (neocortex) specific regions for vision, hearing, touch, movement, emotions, and higher cognitive functions Reproduction internal fertilization – with the exception of monotremes (lay eggs) viviparous most develop a placenta (nourishes embryo and carries off wastes) Respiration muscular diaphragm moves air in and out of lungs Circulation 4 chambered heart with two completely separate circuits (pulmonary and systemic) Limbs many adaptations walking, running, climbing, swimming, burrowing, flying

Mammals placed into two main clades and three groups Clade Protheria (Monotremes) (Protheria = egg laying mammals) Duckbilled platypus and spiny anteaters (Echidnas) Monotremes  Egg-laying Reproduction  Carry eggs in pouch or keep warm in nest

Nourishment of young  Lack nipples – lick milk off fur of mother  Young lap up milk secreted by mother’s mammary glands Clade Theria Distinguishing feature  Mammals that bear live young Two groups 1. Metatheria (kangaroos and opossums)  Pouched mammals (marsupials) 2. Eutheria  Well-developed placenta  Offspring well developed  ~19 orders of placental mammals...