1
Q
Vertebrate phyla
A
- sister to urochordata –> sister to cephalochordata
- part of chordata
- part of deuterostomes (along with echinodermitada and hemichordata)
- part of bilateria
- part of metazoa
2
Q
Unique chordata traits
A
- notochord
- dorsal hollow nerve cord
- pharyngeal slits
- post anal tails
3
Q
Notochord
A
- flexible rod strucure found in embyronic stage of all chordates and adult stage of some
- between digestive tube and nerve chord
- provides skeletal support
- in vertebrates, its replaced with vertebral column
4
Q
Dorsal hollow nerve cord
A
- ectoderm that rolls into a tube during development
- dorsal to notochord
- nerve cord in most chordates develops into brain and spinal cord
5
Q
Pharyngeal slits
A
- openings in pharynx to outside environment
- lets out water that comes in thru mouth during feeding–> also filters food
- vertebrate fish: gill supports
- jawed fish: jaw supports
- tetrapods: ear and tonsil
6
Q
Post anal tail
A
- skeletal muscle and locomotion for aquatic species, like fish
- in vertebrates its for balance or signaling
- in humans, it’s vestigial: reduced in size and nonfunctional
7
Q
subphylum of cordata
A
- Urocordates/ tunicates = invertebrates –> gill slits as adults
- cephalocordates/ lancelets = invertebrates –> notocord as adults
- craniata = have cranium (skull) –> divided into hyperotreti and vertebra
8
Q
hyperotreti
A
- hagfishes
- primitive craniates
- maintain notocord as axial support
9
Q
vertebrates
A
- column of bony vertebrates (vertebral column/spine) replaces notocord
- 2 gps: agnathans (jawless lampreys) and gnathosomes (jawed vertebrates)
10
Q
Extant Fish Clades
A
- jawed fish were earliest gp of gnathosomes and led to diversity, expansion, and further evolution
- cartilaginous fish (chondrichthyes) =sharks, skates, rays
- sarcopterygii = lobe finned fish (bony) = lungfish and coelacanths –> led to tetrapods with limb-like things –> also, air bladders probably became lungs
- Actinopterygii = ray finned fish (bony) = sturgeon, paddlefish, teleosts
11
Q
Teleosts
A
- modern bony fishes –> most derived
- Actinopterygians
- good adapted gas-exchange, locomotion, sensory organs, and buyancy
- gills use counter current method to extract 80-90% of O2
- lateral line = sensory thing that detects vibration
- swim bladder for bouyancy
12
Q
perch gills
A
- supported by gill arch (vertically oriented bony structure)
- gill filaments extend horizontally from gill arch
- gill filaments branch into lamellae which branch into secondary lamellae
13
Q
Gas exchange in bony fish
A
- countercurrent exchange
- secondary lamellae contain 02-poor blood returning from the body
- blood vessels run in opposite direction of water, encouraging O2 to move down the concentration gradient into the blood
14
Q
homology
A
- a similar characteristic in species that’re similar because they’re from common ancestor
- don’t have to have same func. (whale fin vs human arm)
15
Q
analogous structures
A
- look similar and might be used for similar things, but not derived from common ancestor
- can be convergent evolution –> independantly developing traits
- e.g. butterfly, bat, and bird wings
16
Q
Teeth attachment
A
- acrodont = teeth only on top –> fish and amphibians –> not sturdy–> fall out and are replaced a lot
- pleurodont = attached at inner and upper part of jawbone –> reptiles –> slightly stronger bc greater surface area of tooth touches jawbone
- thecodont = strongest –> teeth are firmly fixed in sockets of jawbone –> mammals
17
Q
Teeth shape/size
A
- homodont = all the same; heterodont = different types
- mammals can have up to 4 dif. types: incisers, canines, premolars, and molars
- hypsodont = tall teeth, subject to wear and tear
- brachydont = short teeth –> people
18
Q
Teeth number
A
- ICPM on half of mouth
- if baby teeth are present, put Di, Dc, Dp, or Dm (for deciduous)
