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.
What are Pharyngeal Slits of Clefts?
A characteristic of Chordates, that are pouches separated by groves along the side of the pharynx.
What is the pharynx?
In humans the upper throat area.
What are the grooves separating the pouches in Pharyngeal slits or Clefts?
Known as Pharyngeal Clefts.
What do these Pharyngeal clefts develop into for Vertebretes?
Slits and arches to support gills.
What do Pharyngeal slits allow for in invertebrate Chordates?
A suspension-feeding device allowing water to enter mouth and exit body in invertebrates that need it.
How do Pharyngeal slits develop in Tetrapods?
Develop into parts of the ear, specifically the 3 earbones called the malleus, stapes, and incus. Also develops into different parts of the head and neck.
What are the 3 smallest bones in the ear that are from the Pharyngeal slits?
Malleus, Incus, and Stapes.
What is the Post-Anal Tail?
A tail that Chordates have that extends past the anus. In most species it is mostly present in embryonic development.
What does the Post-Anal tail do for different animals?
For fish it allows for swimming, some for suspension in water, and in terrestrial animals it can indicate behavior or disappears after embryonic development.
What is a Lancelet?
Most basal group of chordates. A small fish like organism with all 4 Chordate characteristics.
What is different between Lancelets and more general Chordates?
Lancelets are very basic, and simple. Believed to resemble the first Chordates.
How do Lancelets eat?
It is a suspension feeder that buries into sediment. Draws seawater in through mouth.
What Phylum are Lancelets in?
Phylum Chordata, subphylum Cephalochordate.
What is a Tunicate?
Marine organisms more closely related to other Chordates.
What is the subphylum of Tunicates?
Urochordata.
What is interesting about the Tunicate genome?
Genes associated with heart and thyroid are found in them 9 Hox genes, other chordates have 13 Nerve impulses unique to vertebretes
What is the development of a tunicate?
They resemble other chordates during larval stage however they undergo drastic metamorphis.
How do Tunicates feed?
Through siphoning water and filtering for particles.
How do Tunicates feed?
Through siphoning water and filtering for particles.
How are Lancelets and Tunicates classified?
Chordates. Cephalochordate (Lancelets) and Urochordate (tunicates). They are the 2 groups of invertebrates within this phylum.
Both are Deuterostome, Chordate, and Invertebrates.
How are jaw-less fish classified?
Chordata, Vertebrata, Agnatha
Hagfish and Lampreys are the only lineages alive today.
What are the characteristics of jaw-less fish?
Eel-like body shape, no jaw, no paired fins or scales, cartilage skeleton, and presence of rudimentary vertebrae.
What common characteristics are used to classify craniates?
They all have a head!
Brain, eyes, sensory organs, and skull.
What are vertebrates with a jaw called?
Gnathostomes.
What is a Hagfish?
Jawless vertebrates that have a cartilage skull, reduced vertebrae, and flexible rod of cartilage derived from notochord.