Introduction Flashcards
1
Q
when did invertebrate animals inhabit Earth’s oceans
A
early Cambrian period, ~530 million years aogo
2
Q
unit of time in geology
A
- eon
- era
- period
- epoch
3
Q
- earth is unstable
- volcanic eruptions
- no atmosphere
A
Hadean Eon
4
Q
- accumulation of organic materials in ocean
- archea
- prokaryotes
- harsh environment
A
Archean Eon
5
Q
- atmosphere established
- oxygen level arise
- suitable for life
A
Protozoic Eon
6
Q
life is diversified
A
Phanerozoic Eon
7
Q
three major divisions of the Phanerozoic Eon
A
- Paleozoic era
- Mesozoic era
- Cenozoic era
8
Q
6 major extinctions
A
- Ordovician
- Late Devonian
- Permian-Triassic
- Triassic-Jurassic
- Cretaceous-Paleogene
- Holocene
9
Q
first organisms to give rise to vertebrates
A
- hagfish
- lamprays
10
Q
- in Devonian period
- came from fish
- developed lobed fins
- has lungs and gills
- gave rise to terrestrial animals
A
Tiktaalik
11
Q
- fishes with legs and arms
- not enough to support body weight
A
Acanthostega
12
Q
fully adapted in terrestrial life
A
Ichthyostega
13
Q
how many species of vertebrates are there
A
57,000
14
Q
bilaterian animals that belong to the clade of animals known as Deuterostomia
A
Chordates
15
Q
two groups of invertebrates under chordates
A
- urochordates
- cephalochordates
16
Q
largest organism to ever live
A
blue whale
17
Q
four key characteristics of chordates
A
- notochord
- dorsal, hollow nerve cord
- pharyngeal slits or clefts
- muscular, post-anal tail
18
Q
- longitudnal, flexible rod between the digestive tube and nerve cord
- provides skeletal support throughout most of the length of a chordate
- adult retains only remnants of it
A
notochord
19
Q
- develops from a plate of ectoderm that rolls into a tube dorsal to the notochord
- develops into the central nervous system
A
dorsal, hollow nerve cord
20
Q
- develop into slits that open to the outside of the body
- suspension-feeding structures in many invertebrate chordate
- gas exchange
- develop into parts of the ear, head, and neck in tetrapods
A
pharyngeal slits or clefts
21
Q
functions of pharyngeal slits
A
- suspension-feeding structures
- gas exchange
- develop into parts of the ear, head, and neck in tetrapods
22
Q
- posterior to anus
- greatly reduced during embryonic develoment in many species
- contains skeletal elements and muscles
- provides propelling force in many aquatic species
A
muscular, post-anal tail
23
Q
- named for their bladelike shape
- marine suspension feeder that retain characteristics of the chordate body plan as adults
A
lancelets (Cephalochordata)
24
Q
- are more closely related to other chordates that lancelets
- most resemble chordates during their larval stage, which may only last only a few minutes
- draws in water through an incurrent siphon, filtering food particles
- shoot water through excurrent siphon when attacked
A
tunicates (Urochordata)
25
number of Hox genes of Tunicates
few
26
genes common to all chordates
associated with heart and thryoid
27
genes unique to vertebrates
associated with transmission of nerve impulses
28
skeletal system and nervous system allowed vertebrates to what
- capture food
- evade predators
29
sets of Hox genes of vertebrates
two or more
30
only one cluster of Hox genes
- lancelets
- tunicates
31
derived characters of vertebrates
1. vertebrae enclosing a spinal cord
2. elaborate skull
3. fin rays, in aquatic forms
32
ectoderm give rise to
skin, nervous system ..
33
mesoderm give rise to
skeletal, circulatory, reproductive ...
34
endoderm give rise to
digestive syst., lungs ...
35
what do earliest vertebrates lack
jaws
36
two lineages of jawless verts that remain today
1. hagfishes
2. lampreys
37
members of hagfishes and lampreys lack what
backbone
38
clade of living jawless vertebrates
cyclostomes
39
clade of vertebrates with jaws
gnathostomes
40
- jawless vertebrates that have a cartilaginous skull, reduced vertebrae, and a flexible rod of cartilage derived from the notochord
- have small brain, eyes, ears, and tooth-like formations
- marine; most are bottom-dwelling scavengers
hagfishes (Myxini)
41
- parasites that feed by clamping their mouth onto a live fish
- inhabit various marine and freshwater habitats
- have cartilaginous segments surrounding teh notochord and arching partly over the nerve cord
lampreys (Petromyzontida)
42
document the transition to craniates
fossils from Cambrian explosion
43
most primitive of the fossils
3 cm long _Haikouella_
44
Haikouella characteristics
- well-formed brain, eyes, muscular segments
- no skull or ear organs
45
- were among the earliest vertebrates in the fossil record, dating from 500-200 million years ago
- had mineralized skeletal elemetns in their mouth and pharynx
conodonts
46
jawless vertebrates that were armored with defensive plates of bone on their skin
jawless armored vertebrates
47
where did mineralization appear to have originated
vetebrate mouthparts
48
became fully mineralized much later
vertebrate endoskeleton
49
outnumber jawless vertebrates
gnathostomes
50
gnathostomes are named for their what
jaws, hinged structures
51
jaws are hypothesized to have evolved by modification of what
skeletal rods that supported the pharyngeal gill slits
52
other characters common to gnathostomes
1. genome duplication, including Hox genes
2. enlarged forebrain associated with enhanced smell and vision
3. in aquatic, the lateral line system which is sensitive to vibrations
53
sensitive to vibrations which is found in aquatic gnathostomes
lateral line system
54
earliest gnathostomes in the fossil record
placoderm
55
when did placoderms appear
~440 million years ago
56
another group of jawed vertebrates that radiated during the Silurian and Devonian periods
acanthodians
57
when did acanthodians radiate
Silurian and Devonian period (444-359 million years ago)
58
three lineages of jawed vertebrates that survive today
1. chondrichthyans
2. ray-finned fishes
3. lobe-fins
