Ch. 15: Chordates Flashcards
1
Q
Unique characteristics of this phylum
A
- Dorsal nerve chord
- Notochord
- Pharyngeal slits
- Post-anal tail
2
Q
Dorsal nerve chord
A
Central nervous system
- Hollow
3
Q
Notochord
A
Axis for muscle attachment
- below nerve chord
- In vertebrates, replaced by bones
4
Q
Pharyngeal slits + endostyle
A
Originally for filter feeding; used for respiration
Endostyle: gland that produced mucus to trap food
5
Q
Muscular post-anal tail
A
For swimming
6
Q
Subphylum’s in Chordates
A
- Cephalochordata
- Urochordata
- Craniata
7
Q
Subphylum Cephalochordata
A
- Marine lancelet, amphixious
- Retain all 4 chordata characteristics
- Filter feeders
8
Q
Subphylum Urochordata
A
- Tunicates or sea squirts
- Larvae has all 4 chordata characteristics
- In adults, notochord and tail disappear
- Nerve chord is reduced
- Ascidian feeding: water circulation
9
Q
Subphylum Craniata
A
Agnatha & Gnathostomata
- Notochord disappears and is replaced with vertebrate
- Tail remains in some
- Living endoskeleton, cranium + vertebrate
- Endoskeleton made of calcium phosphate
10
Q
Group Agnatha
A
Subphylum Craniata
- Without jaws
- Hagish
- Cranium but no vertebrate
11
Q
Group Gnathostomata
A
Subphylum Craniata
- With jaws
- Cranium & vertebrate
- Fish, reptiles, mammals
12
Q
Origin of jaws
A
Modification of the two first pharyngeal slits
