Chordate characteristics Flashcards
How many chordate characteristics are there?
- Notochord
- Dorsal, hollow nerve cord
- Pharyngeal Slits
- Postanal tail
What is the first skeletal feature to appear?
Notochord
What is a notochord?
A supportive rod of living cells just ventral to the nerve cord
What happens to the notochord in fishes and amphibians?
Notochord persists the length of the trunk and tail but is constricted within the centrum of each vertebra
What happens to the notochord in reptiles, bird and mammals
Notochord also disappears during development
What does the dorsal hollow nerve chord orginate as?
a groove along the length of the dorsal surface
How is the dorsal hollow nerve chord formed?
By the grooves folding creating a longitudinal dorsal hollow nerve chord
The nerve chord form _____ to the notochord ….
Dorsal
What does the dorsal nerve chord form?
The central nervous system
- brain and spinal cord
- nerve connection to muscle sin the body for locomotion
Describe the post-anal tail?
extension of the notochord. and the nerve chord that extend past the anus
Do all vertebrates have a post-anal tail?
No, some adults of certain groups don’t
- examples: some primates and frogs
What is a multipurpose chamber?
The pharynx, immediately caudal to the oral cavity
How is the pharynx perforated?
By slits which are separated by pharyngeal arches
What was the pharyngeal slit originally used for?
Filter feeding
What were the pharyngeal slits taken over by in aquatic groups?
Respiratory system
