Chordates. Chapt.1 Flashcards
Define chordates (explaining every term in it
Chordates are deuterostome ceolomates in which at one stage of their life posses a notochord, dorsal hollow nerve cord, endostyle and post anal tail.
Notochord is a stiff dorsal supporting rod defining the longitudinal axis in the embryo
Dorsal hollow nerve cord is what differentiates into spinal cord and brain.
Endostyle becomes slits open to the outside in vertebrae with gills and leave no external feature in those without gills
Post anal tail extends beyond the anus
Differentiate between protosomes and deuterostome
Protosomes are organisms in which the mouth first develops before the anus
Deuterostome are organisms in which the anus first develops before the mouth
What grows to accommodate the spinal cord
Notochord
What is responsible for nervous coordination
Dorsal hollow nerve cord
Classify chordates and list their examples
Urochordates -ascidians, Sea squirts
Cephalochordates -amphioxus
Vertebrae - organisms having vertebral column
What are acorn worms
They are group of marine invertebrates called hemichordates
What is coccyx
Tail bone
Differentiate between bentic and pelagic animals
Benthic - bottom dwelling and sessile
Pelagic - floating and swimming in Open water
Divisions of tunicates
They are divided into 3 class
Class Ascidians
Class appendicularia
Class thaliacea
Why are urochordates refered to as tunicates
Because they posses a notochord in their tail
What are pyrosomes and dolioloids
Pyrosomes form long tubular colonies
Dolioloids occur as solitary individuals and as chains
In urochordates only one class mature into adults..
What class is that
Class Ascidians
They lose the tail and it’s notochord
Which class of urochordates larva don’t feed
Class Ascidians
What is the light sensitive receptor cell
Ocellus
What is otoliths
A receptor for stereoreception
