Chapter 23 Chordates

Question 1

Vertebrate diversity

Answer 1

50,000 living vertebartes, for each living species–>ten extinct

Question 2

Features that characterize chordates(4)

Answer 2

Nerve cord, Notochord, Pharyngeal slits, postanal tail

Question 3

3 Clades of Chordata

Answer 3

Urochordata,Cephalochordata= nonvertebrates, Craniata (includes vertebrates)

Question 4

Urochordata (4)

Answer 4

Also called Tunicates, marine animals, many secrete tunic (cellulose sac surrounds animal), young have notochord and nerve cord

Question 5

Cephalochordata (4)

Answer 5

Lancelets, scaleless chordata, notochord throughout life, closest relatives to vertabrates

Question 6

Craniata

Answer 6

animals with a cranium

Question 7

Agnathans (3)

Answer 7

Jawless fish, not monophyletic, Hagfish/lamprays

Question 8

Vertebrata (6)

Answer 8

Ridgid (bony) spinal column, vertebral column-encloses and protects dorsal nerve cord, head, Neural crest, closed circulatory system, Endoskeleton

Question 9

Vertebrata internal organs (4)

Answer 9

liver, kidney, endocrine glands, heart

Question 10

Neural crest

Answer 10

group of embryonic cells that forms many vertebrate structures

Question 11

Gnathostomes (3)

Answer 11

Jawed vertebrates, cartilagenous and bony fish, fish=single-loop blood circulation

Question 12

Chondrichthyan (6)

Answer 12

cartilagenous fishes(sharks), Ampullae of Lorenzini-electroreceptive organ, placoid scales, rows of teeth, conspicuous gill slits, variety of feeding habits

Question 13

Osteichthiyes

Answer 13

Bony fish, 2 major groups- Lobe-finned fish(scaropterygii)& Ray-finned fish (Actinopterygii)

Question 14

Lobe-finned fish

Answer 14

includes lungfish and coelacanths, where tetrapods diverged,

Question 15

Ray-finned fish (4)

Answer 15

Includes all other bony fish, largest group-teleostei, premaxilla mobile(allows for protrusion or moving of jaw), HOMOcercal tail

Question 16

Tetrapoda (6)

Answer 16

terestrial vertabrates,( No ansectrial fish forms alive today-closest relatives are lungfish), Four limbs, five digits on each limb, Stapes & tympanum, first vertabra modified into atlas (nodding & rotation of head)