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Unformatted text preview: DeuterostomesEchinodermata & Chordata Exercise #10
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Table 9-1 # Germ Layers Coelom type Cleavage type Development Type Blastopore Fate Protostome 3 schizocoelus spiral Determinant Mouth Deuterostome 3 Enterocoelus Radial Indeterminant Anus In this lab we will study the two major deuterostome phyla: echinoderms and chordates.
2 Protostomes Deuterostomes 3 Stem Cell Research The indeterminate cleavage of deuterostomes results in embryonic stem cells that are undifferentiated. This has lead to years of medical and political debates. What do you think??
4 http://www.worldnetdaily.com/news/article.asp?ARTICLE_ID=46546 http://www.timesonline.co.uk/tol/life_and_style/health/article1637528. ece http://www.frc.org/get.cfm?i=IS06H01 http://www.frc.org/get.cfm?i=IS08G01 http://www.frc.org/get.cfm?i=IS09A02 http://blog.wired.com/wiredscience/2008/03/stem-cells-for.html http://www.youtube.com/watch?v=LsxBhBsLNg8 http://www.washingtonpost.com/wpdyn/content/article/2006/03/24/AR2006032401721.html Part 1: Phylum EchinodermataSea Star, Brittle Star, Sea Urchin, Crinoid, Sea Cucumber “Spiny skin” Secondary (penta)radial symmetry (developmentally they are bilateral) Water vascular system Tube feet for locomotion, feeding, and respiration Slow moving or sessile Calcite skeleton Coelom has circulatory, respiratory, and excretory functions.
6 “spiny skin”
Triploblastic Deuterostomes Spiny Protective Skins Penta-Radial Symmetry Water vascular system with tube feet Slow moving/sessile Calcite skeleton Coelom has circulatory, respiratory, & excretory functions 6 classes (we will study 5)
7 Water Vascular System Hydraulic canals for feeding, locomotion, gas exchange Tube feet, radial canals, madreporite Can use tube feet to pry open clam shells. Eviscerates stomach to consume the clam… Eeeewwwwww!!! 8 Internal skeleton composed of calcite plates called ossicles Spines extend from ossicles Hence “spiny skin” 9 Echinoderm Classes
Asteroidea Crinoidea Echinoidea Ophiuroidea Holothuroidea 10 Class Asteroidea: Sea Stars
5+ Arms Ventral Mouth Dorsal Anus Tube Feet with Suckers
Some are carnivorous…some are even cannibals!!! Can regenerate arms… Sweeeet!!!
11 Starfish Dissection I.D.
Oral/Aboral Sides, Central Disc, Mouth, Madreporite, Tube Feet, Digestive Gland, Gonads, Radial Canal, Ampulla, Ossicles
http://www.cumberland.k12.i l.us/Schools/CHS/Starwalt% 20Projects/Starfish/starfish_ 12 dissection.htm Class Ophiuroidea: Brittle Stars & Basket Stars
Central Disc with long, flexible arms Do not have bumpy skin extensions Tube feet lack suckers and are used for locomotion & sensory perception Sea stars and brittle stars an reproduce asexually by breaking themselves in half and regenerating 13 Class Echinoidea: Sea Urchins & Sand Dollars
Unevenly spherical or discshaped Lack arms 5 rows of tube feet cause SLOW locomotion Can actually move spines toward a predator 5 teeth on the oral surface are part of a feeding apparatus called Aristotle’s Lantern Sea urchins are often eaten in Japan 14 Echinoid Anatomy I.D.
Spines, tube feet, oral surface, aboral surface, test, Aristotle’s Lantern 15 Class Crinoidea: Sea Lilies & Feather Stars
Most are sessile (Sea Lilies) and resemble plants Typically attach to coral or sponges Feathered Arms around a dorsal mouth Filter Feeders Tube feet do not have suckers and help to move food toward their mouth Feather stars lack stalks 16 Class Holothuroidea: Sea Cucumbers
Elongated shape 5 rows of tube feet
Some tube feet have been modified to be feeding tentacles (filter feeders) Lack spines & have reduced endoskeleton Eviscerate organs to avoid predators… don’t worry… they regenerate =) Some so sticky that you have to scrape skin to get them off. Used as a soup base in Asia
17 Phylum Chordata: Tunicates, Lancelets, & Vertebrates
ALL chordates will exhibit 4 traits at some point in their development!
Character States Notochord Description Chordate Characteristics
Longitudinal flexible supporting rod between the gut and nerve ALL Chordates exhibit 4 traits at some point cord. Replaced by skeleton in adult vertebrates during their development: Notochord Dorsal hollow Rolled tube of Dorsal Hollow ectodermal tissue located dorsal to the notochord. Nerve Cord nerve cord Forms brain and spinal cord in adults. Pharyngeal Gill Slits Post-anal Tail
Pharyngeal gill slits Pouches separated by grooves along sides of embryonic pharynx. Develop into gill slits in invertebrates, gills in aquatic vertebrates, structures of head or neck in terrestrial vertebrates. Present during some embryonic stages, may be lost in later stages.
18 Post-anal tail Notochord
flexible, longitudinal rod of cartilage Located between the gut and the dorsal nerve cord In humans and some other chordates, replaced by vertebral column. “Disks” in between vertebrae are all that remains
19 Dorsal Hollow Nerve Cord
Ectoderm that has rollup into a tube Hollow, dorsal to notochord Will develop into the central nervous system 20 Spina Bifida-results from Incomplete neural tube Closure Pregnant Women: Eat your Folic Acid!!! 21 Pharyngeal Gill Slits
Openings between the pharynx and outside in primitive organisms Filter food and particles, can also be used for gas exchange Develop into head/neck structures in terrestrial vertebrates 22 Post-anal Post-anal Tail
sometimes only seen in development 23 Subphylum Urochordata: Tunicates (Sea Squirts)
Most primitive chordate group Larvae (free swimming) have all 4 chordate characteristics
Notochord, nerve cord and tail lost as an adult Filter feeders Sac with two siphons in which water exits and enters Be able to ID larva slide and preserved adults Know structures described in figures 9-14 and 9-15b 24 Subphylum Cephalochordata: The Lancelets
Adult retains all 4 chordate characteristics Bilateral symmetry Notochord extends to front of head Burrow in the sand and only leave anterior end exposed Filter feeders On slides, ID: Bucal cirri, Pharynx, Pharyngeal gill slits, Nerve cord, Notochord, & Coelom
In Discovery Bay, Jamaica, can Encounter 5000 per square meter!
Craniates are chordates possessing a head. Class Myxini (hagfish)
Skeleton/skull made of cartilage Jawless No backbone Well developed notochord Ring of tentacles around their mouth Good sense of touch and smell (bad sight) :-) Burrow in dead or dying animals and eat them from the inside out :-) Sneeze to unclog their nostrils of slime 26 Subphylum Vertebrata 1) Backbone that replaces most of the notochord and encases the nerve cord 2) Bony skull surrounds the brain 27 Class Cephalaspidomorphi: Lampreys
Jawless Rudimentary backbone consisting of cartilaginous skeleton Adults are parasitic Larvae resemble Lancelet Rasping tongue to suck blood No mineralized skeleton 28 Gnathostomes
1) Two sets of paired appendages 2) Have jaws 29 Class Chondricthyes: Sharks, skates, & rays
“skeleton” made up entirely of cartilage Teeth and some vertebrae are calcified but not true mineralized skeleton Have jaws Have paired appendages 30 31 Class Actinopterygii: Ray-finned Ray-finned Fishes
Bony rays with tissue in between Upper jaw bones free from skull Swim bladder allows for neutral buoyancy Mineralized skeleton E.g. carp, perch, bass 32 Class Actinistia: Actinistia Lobe-finned Fishes
Bones in appendages homologous to those of tetrapods Most members extinct Thought to have died out 70 million years ago Coelacanths Found 125-250 meters in ocean 33 Class Dipnoi: Lungfishes
Have both gills & lungs Can walk on their fins for short periods of time 34 Fish Features to I.D.
Dorsal, caudal, pectoral, pelvic and anal fins Shark Spiracle Gills (how many slits?) Teeth made of dentine Placoid vs. cycloid scales Shark Placoid Scales Cycloid Scales
35 And the vertebrates come ashore… Developing: 1. Amniotic Eggs 2. A protective integument 36 Class Amphibia
Incompletely terrestrial, still tied to water Live on land
Skin (integument) contains keratin to protect against some desiccation Gas exchange through their moist skin (also have lungs) Eggs laid in water and fertilized externally
37 Enter: The Amniotic Egg
Amnion: fluid-filled membrane that protects the embryo Allantois: membrane used in gas exchange and waste removal Yolk Sac: nourishes the embryo Chorion: encloses the embryo & all internal membranes Shell: prevents desiccation & allows gas exchange Includes Reptiles, birds, & some marsupials
Most are strictly terrestrial Tough skin made of keratin (epidermal scales) does not need water and prevents water loss Leathery shells on amniotic eggs prevent water loss These are adaptations for living on land Includes Snakes, Lizards, Crocodiles, & Birds 39 Class Aves????
Birds Hollow skeleton, allows flight Feathers-warmth and flight
Have contour and down feathers (shape & insulation) Flight feathers No bladder Eggs laid externally 40 Class Mammalia
Humans, cats, dogs, etc.
What characteristics are necessary to be a mammal? 41 Mammals
All mammals are warm blooded. Most young are born alive They have hair or fur on their bodies Every mammal is a vertebrate All mammals have lungs to breathe air Mammals feed milk to their babies. 42 Trivia: Trivia:
What mammal is not only POISONOUS but also lays EGGS?!?! The Duck-billed Platypus! 43 Videos Videos
http://video.google.com/videoplay?docid=1118220941114457469&q=ai r+jaws&total=137&start=0&num=10&so=0&type=search&plindex=0 http://video.google.com/videoplay?docid=7506456136428008603&q=s ea+cucumber+defense&total=2&start=0&num=10&so=0&type=search& plindex=1 http://video.google.com/videoplay?docid=1342097120624270913&q=sea+lily&total=153&start=0&num=10&so=0 &type=search&plindex=0 http://video.google.com/videoplay?docid=413632121100863089&q=ha gfish&total=46&start=0&num=10&so=0&type=search&plindex=0 (Air Jaws, sea cucumber defense, sea lily walking, hagfish defense) 44 Lab Safety – Biology 112 Exercise 10 - Deuterostomes
Goggles and closed-toed shoes are required. Gloves need to be worn when performing dissections. Do not eat or drink in lab. Follow general safety precautions and use common sense in addition to these guidelines. Ask your TA if there is doubt about any procedure.
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This note was uploaded on 10/20/2009 for the course BIOL 112 taught by Professor Vaughn during the Spring '08 term at Texas A&M.
- Spring '08