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Chordata. Intro, Urochordata and Cephalochordata. Victor Pontis & Kaushik Sahoo AP Bio Period 3 Rall. http://www.aboututila.com/PhotoGallery/DeepBlue/Photos/Bluebell-Tunicate-01.jpg. Intro to Chordata. http://myphlip.pearsoncmg.com/altcc/student/ab2page.cfm?vbcid=10440&vid=19992.
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Chordata Intro, Urochordata and Cephalochordata Victor Pontis & Kaushik Sahoo AP Bio Period 3 Rall http://www.aboututila.com/PhotoGallery/DeepBlue/Photos/Bluebell-Tunicate-01.jpg
Intro to Chordata http://myphlip.pearsoncmg.com/altcc/student/ab2page.cfm?vbcid=10440&vid=19992
Characteristics of Chordata Deutorosomes, Bilaterally Symmetrical • Four key characteristics: • Notochord - skeletal • Dorsal, hollow nerve cord - CNS • Pharyngeal slits or clefts – “gills” • Muscular, post-anal tail http://myphlip.pearsoncmg.com/altcc/student/ab2page.cfm?vbcid=10440&vid=19992
Nicknamed "Sea Squirts" Has body cavity that holds the atrium Bilaterally Symmetrical Nervous system degenerates after larval stage. Some cells detect light and gravity allowing it to settle on a substrate. Limited nervous system in adult stage. Tunicates Overview Tunicates are members of the subphylum Urochordata http://www.marinemedicaltreasures.com/images/tunicates.jpg
Incurrent siphon sucks water Atrium filters food Water and waste excreted through excurrent siphon Food travels from esophagus to stomach Siphons also function as circulatory system Digestive, Excretory, and Circulatory Systems http://myphlip.pearsoncmg.com/altcc/student/ab2page.cfm?vbcid=10440&vid=19992
Uses tail muscles and notochord to swim as a larvae Excurrent siphon can do jet propulsion Locomotion/Musculature
Larval stage has notochord and dorsal, hollow nerve chord In adult form the skeleton is lost and resorbed Light and gravity sensing cells Skeletal Type/Sensory Structures
Hermaphrodite = both male/female Settles on substrate Light and gravity cues Chordate characteristics disappear as adult Reproduction
Water is sucked in and pushed out through siphons Diffusion Gas Exchange
Sample Example Organisms Class: AscidiaceaOrder: PleurogonaSuborder: StolidobranchiaFamily: PyuridaeGenus: HalocynthiaSpecies: H. roretzi Sea Pineapple http://upload.wikimedia.org/wikipedia/commons/7/7e/Halocynthia_roretzi-Sea_pineapples_at_Tsukiji_Market-01.jpg http://www.biodiversity911.org/biodiversity_basics/why_important/images/red_sea_tunicates.jpg
Lancelets/Cephalochordata • In the lavaral form lancelets develop a notochord, a dorsal, hollow nerve cord, numerous pharyngeal slits, and a post-anal tail. • Body Cavity is present. • Bilateral Symmetry • Feed on plankton. • Adult lancelets up to 5 cm long • Frequently swim to new locations • Lanclets- globally rare http://myphlip.pearsoncmg.com/altcc/student/ab2page.cfm?vbcid=10440&vid=19992
Nervous System • Lancelets develop a hollow nerve cord • Have slightly swollen tip on the anterior end of their dorsal nerve cord • However, no true brain http://myphlip.pearsoncmg.com/altcc/student/ab2page.cfm?vbcid=10440&vid=19992
Circulatory System • Water enters mouth and passes through the pharyngeal slits into the atrium • The atrium is a chamber that vents to the outside by way of the atriopore • No heart and blood cells
Digestive System/Excretory System • Mucous net around pharyngeal slits remove small food particles from seawater • Ciliary pumping draws these particles into the mouth • Trapped food enters the intestine • Food finally leaves through anus
Locomotion/Musculature • Swimming mechanism of fishes • Coordinated contraction of muscles • Serially arranged segmental muscles • Muscle segments develop from blocks of mesoderm-Somites • Undulatory (wavelike) movements
Skeletal Type/Sensory Structures • As larvae develop a dorsal, hollow nerve cord and notochord • Somites found along each side of notochord • Tentacles by mouth act as sensory devices, and as a water filter • No eyes, or complex sensory structures
Reproduction • Sexual Reproduction • Lanclets have separate sexes - Male & Female • Eggs and Sperm released into water • Fertilized eggs develop into larvae
Gas Exchange • Diffusion across external body surface • Pharynx and Pharyngeal slits play a minor role in gas exchange
http://www.uic.edu/classes/bios/bios100/labs/lance.jpg Lancelets are globally rare, but can reach large densities (5000/m2) in areas like Tampa Bay http://cfs15.tistory.com/image/32/tistory/2009/02/01/04/13/4984a2d26fa8e
QUIZ TIME! 1) Which of following outline the notochord, and are prevalent in all chordate embryos? A. Atriums B. Somites C. Siphons D. Tunics
QUIZ TIME! 1) Which of following outline the notochord, and are prevalent in all chordate embryos? A. Atriums B. Somites C. Siphons D. Tunics
QUIZ TIME! 2) Mature tunicates are able to move by A. their muscles. B. clinging to other animals as they pass by. C. teleportaion. D. jet propulsion.
QUIZ TIME! 2) Mature tunicates are able to move by A. their muscles. B. clinging to other animals as they pass by. C. teleportaion. D. jet propulsion
QUIZ TIME! 3. Chordates are A. bilaterally symmetrical. B. radially symmetrical. C. not symmetrical at all. D. aesthetically symmetrical.
QUIZ TIME! 3. Chordates are A. bilaterally symmetrical. B. radially symmetrical. C. not symmetrical at all. D. aesthetically symmetrical.
QUIZ TIME! 4. Tunicates _____ and Lancelets _____. A. are sexual; are asexual B. are asexual; are sexual C. have separate sexes; are hermaphrodites D. are hermaphrodites; have separate sexes
QUIZ TIME! 4. Tunicates _____ and Lancelets _____. A. are sexual; are asexual B. are asexual; are sexual C. have separate sexes; are hermaphrodites D. are hermaphrodites; have separate sexes