Term
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Definition
| any of a group of ancient jawed fishes from the devonian peoriod. |
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Term
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Definition
a chordate animal with a backbone: the mammals, reptiles (including birds) and amphibians, sharks, and rays, ray-finned fishes and lobe-fines. they from the phylum chordates.
1. they are bilaterally symmetrical)
2. also belong to clade animals knowns as deuterostomes.
3. the two groups of cephalochordates are more closely related to vertebrates than other invertebrates. |
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Term
| derived characters of chordates: |
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Definition
all chordates share a set of these traits:
A). NOTOCHORD
B). DORSAL
C).HOLLOW NERVE CORD
D). PHARYNGEAL SLITS OR CLEFTS
E). MUSCULAR POST-ANAL TAIL. |
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Term
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Definition
| is a longituinal, flexible rod located between the digestive tube and the nerve cord. it provides skelton throughout most of the lenght of a chordate in(larvae or adults that retain it)provides a firm but flexible structure against which muscles can work during swimming.( in vertebrates a more complex jointed skeleton develops around the ancestral notochord;in humans its reduced to gelatinous disks sandwiched between the vertebrates). |
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Term
| DORSAL, HOLLOW NERVE CORD |
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Definition
| the nerve cord of a chordate embryo develop from a plate of ectodem that rolls into a tube located to the notochord (is unique to them)it develops to central nervous system: the(brain and spinal cord. |
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Term
| PHARYNGELA SLITS OR CLEFTS |
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Definition
CLEFTS: develop into slits that open
the outside of the body.
PHARYNGELA SLITS -allow water entering digestive tract. (they function as suspension-feeding devices in many invertebrates chordates.
Are modified for gas exchange in aquatic vertebrates
Develop into parts of the ear, head, and neck in terrestrial vertebrates |
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Term
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Definition
Chordates have a tail extending posterior to the anus
Although in many species it is lost during embryonic development
The chordate tail contains skeletal elements and muscles
And it provides much of the propelling force in many aquatic species
Tail extends posterior to anus
Contains skeletal elements, muscle
Provides propelling force in aquatic species
Tail extends posterior to anus
Contains skeletal elements, muscle
Provides propelling force in aquatic species
Tail extends posterior to anus
Contains skeletal elements, muscle
Provides propelling force in aquatic species
Tail extends posterior to anus
Contains skeletal elements, muscle
Provides propelling force in aquatic species
Tail extends posterior to anus
Contains skeletal elements, muscle
Provides propelling force in aquatic species
Tail extends posterior to anus
Contains skeletal elements, muscle
Provides propelling force in aquatic species
May be lost during embryonic development |
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Term
| Cephalochordata (Lancelets) |
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Definition
Larvae: Free swimming, planktonic feeders All four chordate characteristics
Adult
More sessile
Water leaves thru gill slits
Traps food in mucous net
Retain chordate characteristics
(paedomorphosis)Suspension feeders
Adults retain all chordate characteristics |
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