Vertebraes C34 Flashcards
What are the descendants of Deuterstomia to Amniotes?
Chordates, Vertebraes, Gnatosomes(jaw), Osteichthyans(lungs&bone structure), Lobe-fins, Tetrapods, Amniotes
Qualities of a Gnathosome?
Vertebraes with Jaws (gnaw)
enlargened forebrain
Lateral line system (sensitives to vibrations)
Genome duplication (4 Hox genes)
Oviparous vs. ovoviviparous vs. viviparous
Viviparous: the young are born alive after having been nourished in the uterus by blood from the placenta (NO EGG)
Oviparous: young hatch from eggs laid outside the mother’s body
Ovoviviparous: in which young hatch from eggs that are retained in the mother’s uterus (lay eggs and hatch inside mother’s body)
What does Chordates split up into?
Cephalochordata and (Vertebraes + Unichordata)
Qualities of Vertebraes?
2 sets of Hox genes
Neural crest
Vertebrae surrounding spinal chord
elaborate skull
fin rays (for aquatic forms)
What does vertebraes split up into
Gnatostomes and cyclostomes
Qualities of gnatostomes
have jaws
lateral line fish system
good sense of smell (enlargened forebrain)
What is an Osteichyans
class of gnatosomes
Qualities of Osteichyans
have lungs
bony osified skeleton
Qualities of Lobe-fins
rod-shaped bones surrounded by thick muscles in pector and pelvis fins
Tetrapods
4 limbs
feet with digits
neck
NO GILLS (except some marine animals,ex:tadpoles)
What classes are fish found in?
Dipnoi(lungfish), Actinistia(coelanths), Actinoptoygii(ray-fish)
What is the Tiktaalik?
fossil discoverd in Canada that had both fish and tetrapods characteristics
- had fins, gills, and lungs, and its body was covered in scales
-also had a NECK, ribs and shoulders
What are cyclostomes?
all vertebraes that DONT have jaws, has 2 classes
Classes of cyclostomes? What are organisms in those classes?
Myxini (hagfish) and Petromyzontida (lampreys)
Classes of tetrapods?
Amniotes and amphibians
What is an Amniote?
a group of tetrapods with an amniotic egg
Ectothermic vs. endothermic
Ectothermic, absorb heat from surroundings
Endothermic, generate their own heat through metabolism
Qualities of an Amphibian?
moist skin to help lungs with gas exchange
Qualities of amniotes
have amniotic eggs
membranes that make up embryonic egg (amnion, chorin, yolk sack and allantois)
impermeable skin
rib cage to ventilate
Qualities of mammalia
mammary glands (milk)
hair
endothermic (metabolic rate)
larger brain
diffrential teeth
Qualities of reptiles
Lizards
Have scales
Lay shelled eggs
ectothermic, but birds are endothermic (get heat through metabolism)
What are the 2 invertebrae classes of chordates?
Unichordata and cephalochordata
