Chordates

What form of symmetry do Chordates display

bilateral

Are chordates protostomes or deterurostomes?

deuterostomes

What are the 4 unique structures of chordates?

Hollow dorsal nerve cord, notochord, Pharyngeal slits, post-anal tail

Describe the structure of the hollow dorsal nerve cord

Plate of ectoderm rolled into a tube

What is the purpose of the hollow dorsal nerve cord

Develops into CNS, brain and spinal cord

Describe the structure of the notochord

Longitudinal, flexible rod

Fluid-filled cells in fibrous tissue

What is the purpose of the notochord?

Structural support

Describe the structure of the pharyngeal slits

Series of pouches separated by grooves on side of pharynx

What is the purpose of the pharyngeal slits?

Modified for gas exchange (gills) or parts of ear and other structures

Describe the structure of the post anal tail

Largely reduced in vertebrates

What is the purpose of the post anal tail?

Swimming in species that retain it

What are the 3 subphyla of chordates?

Urochordata – tunicates
Cephalochordata – lancets
Vertebrata

How are adult Urochordate different from the juveniles

They loose their notocord, segmentation and body cavity

They are sessile

What species are within the cephalochordata

lancets

What is a myomere

the muscle blocks of cephalochordata

Can cephalocordata see?

no but they can sense light via light receptors

What is a Craniate

possesses a hard skull (cranium)

What are some examples of the musculoskeletal upgrades vertebrates received?

Bony vertebrae

Bony case surrounding the brain

Flexible repairable endoskeleton

What are some physiological upgrades vertebrates received?