Course Content: Pre-Midterm Flashcards
Why can it be easier to study vertebrate evolution, vs. invertebrate evolution?
Skeletons comparatively well preserved
Are most vertebrates terrestrial?
No, about half are fish
Basic vertebrate features (6)
- Bilateral symmetry
- Regional differentiation
- Craniata
- Post-anal tail
- Pharyngeal gill slits
- Notochord
Basic chordate features (4)
- Post-anal tail
- Pharyngeal gill slits
- Notochord
- Dorsal tubular nerve chord
What advantage is bilateral symmetry correlated with?
Increased movement and activity, which is the key to evolutionary success
Organisms with this body plan are generally more active and can move farther than organisms with radial symmetry
vertebrate cephalic region
houses the principle sense orangs and brain, also where the mouth usually is
A better name for vertebrates
Craniata
ALL vertebrates have a bone or cartilage structure surrounding the brain, but some have no vertebral column
branchial region
the neck
thicker in aquatic vertebrates, contains gills
trunk
extends with the digestive tube to the anus/cloaca
post-anal tail
in aquatic creatures, used for motion
a defining characteristic of chordates and therefore vertebrates
pharyngeal gill slits
paired series of pouches leading outward from the pharynx of the digestive system
notochord
long, flexible rod from head to tail on the dorsal side of vertebrates
is often absent or replaced by a vertebral column in adults
Key component of chordate nervous system
dorsal tubular nerve chord protected by vertebral column
Key features of chordate digestive system
anterior and posterior openings
food makes a unidirectional trip (leaves out a different opening than it came in)
Do all chordates have skeletons?
Yes
Only vertebrates, and not all vertebrates, have bone though
If not bone, cartilage
