TOPIC 27: vertebrates Flashcards
ancestral chordates resembled
lancelets
vertebrates
chordates that have a vertebral coloumn (backbone)
how did vertebrates arise:
through the evolution of invertebrates
vertebral column
Cartilage or bone protects the nerve cord, replaces function of notochord
invertebrate eleborate brain enclosure
protects the brain, increased cephalization
do vertebrates have a cranium with or without jaws
with jaws
how many sets of hox genes in a vertebrate?
two or more
invertebrates nueral crests
developed along the nueral tube edge in vertebrate embryos and contribute to structures such as teeth
how are dorsal, anal and tail fins stiffened
with fin rays alongthe centerline
what makes a vertebrate circulatory system complex and modified?
- two chambered heart
- oxygen transporting cells
- kidneys to remove metabolic waste
what does the complex circulatory sytem help with
helps with increased metabolic rates and more muscularity
something the earliest vertebrates lacked
jaws
something both lamphrey and hagfishes lack? and are they both invertebrates or vertebrates?
backbone and a jaw, vertebrates
cyclostomes
round mouths
jawless vertebrates that have a cartilanginous cranium, reduced vertebrae anf a flexible rod of cartilage from the notochord
hagfishes
gnathostomes
vertebrates with jaws
animals from clade cyclostomes that have cartilaginous skeleton, elaborate cranium, girll basket, and vertebral elements
lamphreys
do lancelets and lamphreys have similar behavious?
yes, both are suspension feeders and bury themselves
earliest vertebrate found in fossil record
conodots
characteristics of conodots
mineralized skeletal elements in mouth and pharynx
vertebral column
gnathostomes
vertebrates with jaws
shared
-opposed jaw
- mineralization o f bones
- 2 pairs of hox LATERAL APPENDAGES
- genome and hox gene duplication
- bigger forebrain
- lateral line system
lateral line system
helps detect vibrations on water
what does a bigger forebrain enhance
smell and vision
earliest vertabrates have ____ skeletons
catiligous
two types of bones
endoskeleton and dermal skeleton
differences in endo and dermal skeleton
endo derived form preformed cartilage
dermal derived from intramemembrane ossifcation
flexible vonnective tissue with an abundance of collagenous fibers embedded in chonfriotoin surface
cartilage
in ganatostomes, cartilages undergoes_____ as the embryo develops
ossification/becomes bony
extinct vertebrate fuish that retained cartilaginous skeleton but find had a wide, bony base and an anterior body spine
acanthodians
have cartiligious skeleton, bony teeth, bony placoid (tooth shaped) scales
chondrichthyans (sharks)
what kind of ventilation do sharks rely on?
ram ventilation
this process incolces sharks swimming with their mouths open that allow oxygen to pass, facilitating in respiration
something sharks do: they open and close their mouths to ventilate their gills
buccal pumping
digestive, urinary and reproductive tracts of sharks (and most vertebrates) empty through a ____
cloaca
3 embryotic development methods in shakrs
oviparous
ovoviviparous
viviparous
embryotic development where embryo is nourished by a yolk in the uterus
ovovoviviparous
laying fertilized eggs outside the mothers body encased in a protective leathery coat
oviparous
embryotic development in the uterus and nourished by a yolk PLACENTA connected to the mothers bloodstream
viviparous
