Exam 5 bio ch 34

what are the main characteristics of chordates

notochord, dorsal, hollow nerve cord, post-anal tail, pharyngeal slits or clefts

what is the notochord

longitudinal flexible rod that provides skeletal support

what is the dorsal, hollow nerve cord

plate of ectoderm that rolls into a tube that leads to the central nervous system

what are the pharyngeal slits or clefts

suspension-feeding structures, gas exchange via gils, ear head and neck

what is the muscular, post anal tail

skeletal elements and muscles, propelling force

what is cephalochordata

lancelets, retain chordate body, hox genes - vertabrate brain but lancelets nerve cord

what is urochordata

tunicates, resemble chordaets during larval stage, metamorphosis resorption tail and notochord

what are derived characters of verevbrates

two or more sets of hox genes and neural crest cells

what were the earliest vertebrates like

lacked jaws, rudimentary

what are gnathostomes

vertebrates with jaws, sharks, reptiles, etc, enlarged forebrain that enhances smell and vision, lateral line system

what are chondrichthyans

skeleton mainly composed of cartilage, largest and most diverse, sharks, rays, etc, buoyancy, shark eggs are fertilized internally, oviparous, ovoviviparous, viviparous

whats the difference between oviparous, ovoviviparous, and viviparous

Oviparous: Animals lay eggs that develop and hatch outside the body.
ovoviviparous: Eggs stay inside the mother and hatch inside, so babies are born live without direct nourishment from her.
viviparous: Babies develop inside the mother and get nutrients directly from her before being born live.

what is osteichthyes

mineralized bones, swim bladder

what are actinopterygii

ray-fined fishes, supported and modified for defense

what are lobe fin sarcopterygii

rod-shaped bones and thick layers of muscles, actinistia, dipnoi, tetrapods

what are dipnoi lungfishes

gills and lungs, estivate, sea snakes

what are tetrapods

gnathostomes with four limbs, feet with digits, pelvic girdle, backbone, pharyngeal slits during embryologic development, ears for airborne sounds

what was the first tetrapod

tiktaalik, has c1 verebra atlas and c2 vertebra axis

what are amphibia

moist skin, larva

what are amniotes

tetrapods that have a egg, extraembryonic membranes

what are repitles

shelled amniotic eggs, scales of keratin, ectothermic

what are archosaurs

turtles, lack hols in skull, boxlike shell

what are the origin of birds

keratin feathers, weight saving adaptations, endothermic

what are lepidosaurs

lizards, snakes, chemical ensors, heat detecting organs, venom, jawbones and elastic skin

what are mammals

amniotes that have hair and produce milk, mmary glands, fat layers, kidneys, endothermic, etc