Chapter 34 Flashcards
When did vertebrates rise and from what?
First sign of vertebrate life is the Myllokunmingia (fish). It had plates resembling a skull, no vertebrae. 530 mya. First fossil evidence of any sort of skull like feature.
How do vertebrates get their name?
The vertebrae or bones in the backbone.
What is a craniate?
An organism with a skull or skull like structure.
How did modern amphibians rise?
It is assumed that one species left sea and through evolution eventually lead to amphibians, reptiles, and mammals.
How many vertebrates are there?
Roughly 57,000. It is a small percentage of organisms but most of the largest organisms to exist are vertebrates. Large variety in many different ways.
What are the derived traits of chordates and identify them.
Notochord
Dorsal hollow nerve chord
Pharyngeal slits of clefts
Muscular post anal tail
What are the derived traits of chordates and identify them.
Notochord
Dorsal hollow nerve chord
Pharyngeal slits of clefts
Muscular post anal tail
What are chordates?
Bilaterian animals that belong to the clade Deuterostomia.
What are the 2 groups of Chordates?
Urochordates and Cephlaochordates.
What are Urochordates?
An example is Tuniates. Have all 4 Chordate traits.
What are Cephalochordates?
An example is Lancelet. Have all 4 Chordate traits.
What’s the difference between Vertebretes and Notachords?
In vertebrates, the bony vertebrae grow around the spinal cord, protecting it on all sides. Animals with only a notochord lack this protection, as the spinal cord sits between the notochord and the skin.
What is the difference between Urochordates and Cephlaochordates?
In Urochordata, the notochord is extended towards the posterior part, forming a tail in the larval stages. In Cephalochordata, the notochord is extended to the anterior part.
Do you have to have a vertebrae to be a Chordate?
No you don’t.
Do all 4 chordate traits have to exist during all stages of life?
No, some chordates only have all 4 of these traits during development.
Do all 4 chordate traits have to exist during all stages of life?
No, some chordates only have all 4 of these traits during development.
What is the Notochord?
A longitudinal, flexible rod, located between nerve cord and digestive tube.
Where is the Notochord present?
In all chordates, in all embryos and some adults.
What is the Notochord made of?
Cells encased in stiff, fibrous tissue, giving skeletal support.
What are some uses for the Notochord?
The muscle structure allows for muscles to work during swimming.
When is a jointed skeleton with the Notochord present?
In most vertebrates a jointed skeleton develops around the notochord & only remnants of embryonic notochord remain.
What is the Dorsal, Hollow Nerve Cord?
A hollow tube located above the Notochord.
Do other phyla’s have Nerve Cords?
Yes, but it is located below usually. .
How does the Nerve Cord develop?
Into the central nervous system of the brain and the spinal cord.