Chordata Flashcards
Gold Packet Exam 3
Chordata
an animal of the large phylum Chordata, comprising the vertebrates together with the sea squirts and lancelets.
Four Characteristics of the Chordata
Notochord, hollow dorsal nerve, pharynx with gill slits, post-anal tail.
Notochord
Flexible but incompressible rod of tissue-stiffening structure-lost in development in “higher” vertebrates.
Hallow dorsal nerve chord
Runs from anterior to posterior of body, along upper midline of body.
Pharynx with gill slits
Pharynx anterior part.
- Wall consists of gill slits between solid gill bars.
- Often lost through development in “higher” vertebrates.
Post anal tail
Area of tissue behind the anus. Sometimes lost through development.
Subphyla Chordates
Cephalochordata, Urochordata, Vertebrata
Cephalochordata
Lancelets- fish without jaw and obvious organs. Most primitive chordates. Invertebrates.
Urochordata
Tunicates (sea squirts) - marine invertebrates. Adults have no notochord, nerve cord, or tail. Body covered in cellulose tunic, filter feed through pharynx.
Vertebrata
Vertebrates with central and peripheral nervous system. , one heart, kidneys for osmoregulation, a coelom, cephalization, .
Vertebrate axial
skull and vertebral column
Endocrine Glands
all vertebrates have these for hormones.
Vertebrates all have…
tail, vertebral column, skeleton, coelom, head, limbs, kidney, heart, jaws, liver, endocrine.
Tetrapod
a four-footed animal, especially a member of a group which includes all vertebrates higher than fishes. (Frog and up)
Jaws evolved from…
anterior gill arches/bars
Agnatha
Cylindrical, smooth, jawless, cartilaginous skeleton, notochord, simple fishes. (Hagfish and lampreys).
Chondrichthyes
(sharks) Torpedo or flattened, placoid scales, mouth behind anterior, jaws, cartilaginous skeleton, 5-7 pairs of gill slits, buoyancy via pectoral fin and oily liver.
Lateral Line Organ and Electroreceptors
Found in Chondrichthyes for detecting vibrations in the water.
Ampullae of Lorenzini
special sensing organs called electroreceptors, forming a network of jelly-filled pores.
Actinopterygii
The bony fish-tall and torpedo shaped. Floats via the swim bladder with an anterior mouth. Gasses go from blood in and out of bladder.
Gravid
pregnant, carrying eggs or young.
Amphibia
Cylindrical or stout, gills to young, Skin is moist granular, for gas exchange, girdles, carnivorous, worldwide decline.
Girdles
Amphibian- where legs attach. Pectoral (forelimbs) and pelvic (hind-limbs).
Chytrid Fungus
an infectious disease that affects amphibians worldwide.
Reptilia
Cylindrical body, lateral appendages, dry scaly skin, lungs, embryo gill slits, uric acid pee, herbivores and carnivores. Reptiles are a paraphyletic taxon.
Reptilia Embryo
Amniotic egg (no water needed), membranes (amnion, chorion, allantois, yolk sac, egg membrane) yolk, albumin leathery shell. Proteins.
Amnion
Keeps egg from drying out for reptiles.
Chorion
Gas exchange for reptile eggs.
Embryo
Baby reptile
Allantois
waste disposal within a reptile egg.
Yolk sac
Nutrient supply
Albumin
Reptile egg part rich in nutrients, shock absorber.
Aves
Birds- porous bones, reduced organs.
Neotropical Birds
Migrate to central and south americas during the cold winters.
Mammals
Pelage, mammary glands on the pecs, viviparous.
Monotremata
Mammals that lay eggs
Marsupial
Mammals with pouches
Placentalia
Animals that have internal development.
Cutaneous Respiration
Amphibians breath through their skin.
Thoracic Breathing
Reptiles shallow breathing.
Synapids
Holes behind reptiles heads.
Archaeopteryx
the oldest fossil bird.
