deuterostomes- chordates

Question 1

deuterostomia are part of the

Answer 1

bilateria

Question 2

2 phyla of deuterostomia

Answer 2

echinoddermata and chordata

Question 3

what constitutes a deterostome

Answer 3

• bilateral symmetry
• coelom (body cavity)
• radial cleavage during embryonic development ; cleavage parallel to vertical axis
• blastopore –> anus

Question 4

echinodermata

(deuterosomes)

Answer 4

starfish, sand dollars, sea urchins, sea lilies, sea cucumbers and brittle stars

Question 5

DNA data indicates that echinoderms are closely related to

Answer 5

chordates

Question 6

echinodermata endoskeleton

Answer 6

• interlocking CaCO3 (calcareous) plates and spines
• covered by a thin epithelium

Question 7

echindermata water vascular system

Answer 7

• unique, network of water-filled canals
• branch to form tube feed
• locomotion and feeding

Question 8

echinodermata sexual reproduction

Answer 8

release gametes into water, spawning

also asexual; autotomy; ie lose an arm “comet” becomes new individual

Question 9

5 classes of echindoermata

Answer 9

1) asteroidea: starfish and sea daisies
2) echinoidea: sea urchins
3) ophiuroidea; brittle stars
4) crinoidea; sea lillies and feather stars
5) holothuroidea; sea cucumbers

Question 10

3 subphyla of chordata

Answer 10

• vertebrata; fish, amphibians, reptiles, bird, mammals
• cephalochordata;amphioxus
• urochordata; sea squirts

Question 11

when did earliest chordate appear

Answer 11

cambrian period 530 MYA

Question 12

4 common feature

Answer 12

• notochord
• pharyngeal slits
• dorsal, hollow nerve cord
• muscular, post-anal tail

Question 13

the 4 common features that define chordates; when are they exhibited

Answer 13

may only be present briefly during embryonic development of may persist into adulthood, but all chordata exhibit them at some point

Question 14

notochord

chordata criteria #1

Answer 14

• slender rod
• develops from mesoderm
• lies dorsal to coelom (body cavity)
• beneath and parallel to CNS (under the brain and hollow nerve cord)
• consists of a core of cells and fluid, surrounded by fibrous sheath

Question 15

how does notochord allow locomotion

Answer 15

through lateral undulations

Question 16

in bony fish and terrestrial vertebrates when is notochord present and what is it replaced by

Answer 16

• embryonic development
• replaced by vertebral column
• persists as nucleus pulposus of the intervertebral discs

Question 17

pharyngeal slits

chordata criteria #2

Answer 17

• longitudinal series of openings in walls of pharynx

Question 18

pharyngeal slits in primitive chordates

Answer 18

involved in feeding

Question 19

pharyngeal slits in terrestrial vertebrates

Answer 19

in embryo phase and lost during embryogenesis

Question 20

pharyngeal slits in aquatic vertebrates

Answer 20

gills develop ADJACENT to pharyngeal slits, slits allow for flow of water across gills

Question 21

dorsal hollow nerve cord

chordata criteria #3

Answer 21

• derived from ectoderm
• lies above hut
• hollow
• surrounds fluid- filled neurocoel

Question 22

muscular, post anal tail

chordata criteria #4

Answer 22

• posterior elongation of body beyond anus
• consists of segmental musculature and the notochord

Question 23

what resembles the earliest chordate, what is a living example

Answer 23

• cephalochordata
• living example is branchiostoma; amphioxus

Question 24

branchiostoma; amphioxus

Answer 24

• subphylum cephalocordata
• blade like in shape
• all 4 criteria of chordate as an adult
• filter feed, mucous nets across slits

Question 25

cephalochordata digestive system

Answer 25

- may be precursor of vertebrate organs - midgut caecum; liver and pancreas

Question 26

cephalochordata circulatory system

Answer 26

- same general pattern as vertebrates - ventral and dorsal aorta - afferent and efferent vessels - capillary networks - NO HEART

Question 27

cephalochordate brain

Answer 27

- shares homology w vertebrate brain - not a rela brain; cluster of cells - expression of genes; similar organization of forebrain, midbrain and hindbrain

Question 28

vertebrate brain is an elaboration of the

Answer 28

cephalochordate brain

Question 29

urochordata

Answer 29

- tunicates - all species marines - class ascidiacea; sea squirts

Question 30

sea squirts

Answer 30

- in urochordata phylum - class ascidiacea - adults sessile, larva planktonic - display 4 criteria of chordates only as larva

Question 31

likely that urochordates and vertebrates

Answer 31

evolved from a common ancestor

Question 32

urochordata (sea squirt) CNS 3 divisions

Answer 32

sensory vesicle, visceral ganglion and nerve cord

Question 33

urochordata (sea squirt) neurel crest cells

Answer 33

- derived from nerve cord - different cell types

Question 34

urochordata (sea squirt) heart and blood

Answer 34

- rudimentary blood - several blood types of cells

Question 35

from the chordates evolved the craniates which are

Answer 35

chordates with a head

Question 36

craniata unique characteristic

Answer 36

is the neural crest

Question 37

most basal of crianates

Answer 37

hag fish

Question 38

hag fish

Answer 38

- most basal craniate - cartilaginous skull - lacks jaw and vertebrae - retain notochord in adult - marine - feed on detritus - produce mucous as defense

Question 39

during cambrian period craniates gave rise to

Answer 39

vertebrates

Question 40

most basal lineage of vertebrates are

Answer 40

lampreys

Question 41

lampreys

Answer 41

- most basal vertebrates - weird looking fish with big circle mouth/ teeth - cartilaginous skeleton - lack jaw - retains notochord in adult - marine and freshwater

Question 42

one of most significant steps in early vertebrate evolution

Answer 42

development of jaws in primitive fish

Question 43

gnathostomes

Answer 43

- vertebrate fish w jaws - transition from suspension feeding to selective feeding - paired pectoral and pelvic fins - 2 lines of evolution: - chondrichthyes; cartilaginous fish - oteichthyes; bony fish

Question 44

chondrichthyes gnathostomes vertebrates chordates

Answer 44

- sharks, rays and relatives - cartilaginous skeleton - cartilaginous vertebral column replaces notochord - lack swim bladder - placoid scales; dentine and enamel with surface denticles - scales project through epidermis - internal fertilizations - males have clasper on pelvic fine - oviparous; tough leathery eggs - AND viviparous; gestation, nutrition via yolk, uterine milk or placenta

Question 45

osteichthyes gnathostomes vertebrates chordates

Answer 45

- bony fish - scales do not penetrate epidermis - swim bladder controls buoyancy - external fertilizations

Question 46

2 subclasses of osteichthyes gnathostomes vertebrates chordates

Answer 46

- actinopterygii; ray finned fish - sarcopterygii; lobe- finned fish

Question 47

actinopterygii; ray finned fish 2 main groups bony fish ie osteichthyes

Answer 47

- neopterygii: teleosts - palaeonisciformes; sturgeons

Question 48

sturgeons

Answer 48

- largest species of freshwater fish - toothless - vertebrata - have a jaw so gnathostomes - bony fish so osteichthyes - ray finned so actinopterygii

Question 49

- sarcopterygii; lobe- finned fish bony fish

Answer 49

- lung fish and coelacanth - flesh fins composed of soft muscle - gave rise to tetrapod limb!

Question 50

where did limbs arise from

Answer 50

lobe finned fish ie subclass sarcopterygii of bony fish osteichthyes gnathostomes vertebrates chordates

Question 51

subclass sarcopterygii

Answer 51

cam breath air when O2 levels in water fall prominent notochord

Question 52

cool ex of sarcopterygii

Answer 52

coelacanth thought ot be extinct but found in 1938 tiny vertebrate possess swim bladder