Chordates Flashcards
(117 cards)
1
Q
Phylum of chordates
A
Chordata
2
Q
Four defining characteristics of juvenile chordates
A
Hollow dorsal nerve cord Notochord Pharyngeal cleft Post anal muscular tail Muscle segments
3
Q
What is the notochord
A
Cartilaginous rod
4
Q
What is the pharyngeal cleft
A
Slots between the mouth and stomach held open by cartilaginous rod
5
Q
What is the common ancestor of chordates
A
Cephlachordata
6
Q
How do cephalochordata feed
A
Filter feed using a mucous net
Release mucous into the water as currents waft plankton passes. Plankton gets stuck in mucus and then the mucus is ingested with the plankton
7
Q
How do Urochordata feed
A
Sucks in water and use pharyngeal slots to filter out food and release water
8
Q
What are tunicates
A
Urochordata
9
Q
What are lancelets
A
Cephalochordata
10
Q
Explain the 2R hypothesis
A
The genome of jawed vertebrates has been shaped by two rounds of whole genome duplication that took place after the emergence of Urochordata but before the emergence of jawed vertebrates
11
Q
How many species of vertebrate chordates
A
66000
12
Q
Differences between cephalochordata and vertebrates
A
Vertebrates have: Large brain Skull Eyes Teeth
13
Q
How many years ago did vertebrates evolved
A
550 MYA
14
Q
What is a myxini
A
Hagfish
15
Q
How do myxini eat
A
Tie themselves on a knot
Push knot up body
Motion helps rip flesh off prey
16
Q
What does agnathans mean
A
Without jaw
17
Q
Describe the structure of a hagfish
A
Agnathans
Cartilaginous skeleton
Well developed notochord
18
Q
What is a petromyzontida
A
Lamprey
19
Q
How many species of lamprey
A
35
20
Q
How do lamprey larvae feed
A
Filter feeders
21
Q
How do adult lamprey feed
A
Parasitic or do not feed
22
Q
Describe the structure of a lamprey
A
Notochord
Simple vertebral column
Mineralisation along notochord - shows segments
23
Q
What are actinopterygii
A
Fin fish
24
Q
What are the three classes of actinopterygii
A
Chondrostei
Holostei
Teleostei
25
What are chondrostei
Sturgeons
| Paddlefish
26
What are holostei
Gars
| Bowfin
27
What are teleostei
Ray finned
28
How many species of chondrostei
45
29
How many species of holostei
9
30
How many species of teleostei
27000
31
Characteristics of actinopterygii
```
Ossified endoskeleton - bones
Skin covered in scales and mucus
Swim bladder
External fertilisation - produce lots of eggs
Pelagic larvae hatch from eggs
Some show parental care
```
32
Characteristics of teleosts
Find supported by rays
| Jaw modifications
33
How do actinopterygii change how much they float
Change the amount of gas in their swim bladder
34
What type of reproduction do guppies show
Ovoviviparous
35
What type of reproduction do tile perch show
Viviparous
36
What is an actinistia
Lobe finned fish
37
What are the two living species of actinistia
Coelacanth
| Latimeria
38
Characteristics of actinistia
Hinges skull
Ovoviviparous
Fleshy fins
39
When were actinistia discovered
1938
After 80 million year absence
40
What is a dipnoi
Lungfish
41
What is the closest living relative to tetrapods
Dipnoi - lungfish
42
Where do lungfish live
Swamps and shallow pools
Can crawl through wet vegetation from one pool to another if the pool dries out
43
How do lungfish breath
Gulp air into lungs
44
How are Osteichthyes characterised
By jaws and mineralised skeletons
45
When did vertebrates evolves
In the Cambrian
46
When did dipnoi evolve
In lower Devonian
47
what are the advantages of jaws
allows efficient feeding
| wider range of food can be eaten
48
what were jaws derived from
cartilaginous structures
49
what 4 clades have jaws
Chondrichthyes
Placoderms†
Acanthodians†
Osteichthyes
50
what are Chondrichthyes
sharks etc
51
how many species of elasmobranchii
1150
52
how many species of holocephali
50
53
what orders make up the chondrichthyes
elasmobranchii
| holocephali
54
what are elasmobranchii
sharks
skates
rays
55
what are holocephali
chimeras
56
how do chondrichthyes float
liver filled with oil - oil floats on top of water
57
what is negative bouyance
means they can float on the sea bed
58
characteristics of chndrichthyes
cartilaginous skeleton reinforced with small bone plates
no swim bladder
carnivores
well developed sense of smell and lateral line system
well developed jaws and paired fins
internal fertlisation
few offspring
59
how do dogfish reproduce
ovipary
60
how do bronze whaler sharks reproduce
vivipary
61
how do sharks reproduce
vivbrous
male uses pelvic fin to transfer sperm to female
eggs fertilised
female gives birth to live young
62
How did the limbs of tetrapods evolve
From the fina of lobe finned fish
63
How old are amphibians
375 MYA
64
What tetrapods include
Amphibians
Amniotes
mammalia
65
When did mammals and birds radiate
Tertiary - 65 MYA
66
When did dinosaurs become dominate
Cretaceous- 135 MYA
67
When did birds evolve
Jurassic - 192 MYA
68
When did the first amphibians evolve
Devonian - 410 MYA
69
When did the first reptiles evolve
Carboniferous- 350 MYA
70
When did reptiles radiate and amphibians decline
Permian - 290 MYA
71
When did the first dinosaurs evolve
Triassic - 230 MYA
72
What are the three orders of amphibia
Urodela
Anura
Apoda
73
What are urodela
Beets and salamanders
74
What are Anura
Frogs and toads
75
What are apoda
Caecilians
76
How many species of urodela
650
77
How many species of Anura
6200
78
How many species of apoda
190
79
Characteristics of amphibians
```
Thin skin with limited keratinisation
Skin permeable to oxygen and water
Most restricted to damp environments
Fertilisation generally external
Eggs have no shell
Fish like larvae
```
80
What are the results of amphibian eggs having no shell
Prone to desiccation and need physical support
81
Describe the larvae of amphibians
```
No legs
No lungs
Have gills
Aquatic herbivores
Lateral line system
```
82
Describe adult amphibians
Terrestrial carnivores
4 legs
Lungs
83
When did amniotes evolve
In the Carboniferous
84
What four specialised membranes make up an amniotic egg
Amnion
Allantois
Yolk sac
Chorion
85
What do the four specialised membranes of amniotic eggs allow
Protection from desiccation
Gas exchange
Store food and waste
86
What is desiccation
State of extreme drying out
87
What does the specialised amniotic egg allow amniotes to be
Truly terrestrial
88
What is the oldest known amniote
Hylonomus
89
What is older than hylonomus and may be an amniote
Westlothiana
90
How old is hylonomus
312 MYA
91
How old is westlothiana
338 MYA
92
What are the two main classes of amniotes
Reptilia
| Mammalia
93
What is an ondotochelys semitestacea
Toothed turtle with a half shell
94
Where is the shell on odontochelys
Underside
95
How old are odontochelys
220 MYA
96
What are testudines
Turtles
97
How many species of testudines
327 species
98
What reptilian characteristics are shown by Testudines
Skull morphology
Scales of beta keratin
Internal fertilisation but lay eggs
Ectothermic
99
What are crocodilia
Crocodiles and alligators
100
How many species of crocodilia
24
101
Crocodilia have a secondary palate - what does this mean
Can breathe from their nose and mouth
102
Why do people believe archaeopteryx was the first bird
Has a mixture of reptilian and avain characteristics
From Jurassic period about 150 MYA
103
How many species of birds
10000
104
How many orders of birds
23
105
Characteristics of birds
```
Beta keratin feathers
Large, keeled sternum
Fore-limbs modified for flight
Hind limbs for bipedal walking
Internal fertilisation but lay hard shelled eggs
Endothermic
```
106
What is the only species in the class sphenodontia
Lizard like carnivorous reptile
107
Where was the only species of sphenodontia found
Island off of New Zealand
108
Why is there only one species in the class sphenodontia
Most went extinct 65 MYA
109
How does the one species of sphenodontia differ from lizards
Different skull but has ancestral features
110
What are Squamata
Snakes and lizards
111
How many species of Squamata
9800
112
Characteristics of snakes
Limbless
Elongate
Modified jaw and skull
113
What is a hadrocodium wui
Mammal
114
When was hadrocodium evolved
195 MYA - early Jurassic
115
Describe the hadrocodium wui
Large brain
| Malleus and incus in ear
116
How many species of mammalia
5450
117
Characteristics of mammals
```
Alpha keratin hair
Specialised teeth
Articulation of jaw between dentary and squamosal bones
Endothermic
Internal fertilisation
Amniotic eggs
Mammary glands
```
