Vertebrates

Question 1

Notochord

Answer 1

longitudinal, flexible rod between digestive tube and nerve cord

Question 2

Nerve cord

Answer 2

develops from a plate of ectoderm that rolls into a tube dorsal to notochord

Question 3

Pharyngeal Clefts

Answer 3

Grooves in pharynx that develop into slits that open to outside of body

Question 4

Functions of Pharyngeal slits

Answer 4

suspension feeding structures in many chordates
gas exchange
develop into parts of ear, head, neck in tetrapods

Question 5

Cephalochordata

Answer 5

Lancelets

marine suspension feeders that retain characters of the chordate body plan as adults.

Question 6

Urochordata

Answer 6

Tunicates - more closely related to other chordates than are lancelets
marine suspension feeders called sea squirts

Question 7

Myxini

Answer 7

craniates - share some characteristics: a skull, brain, eyes, and other sensory organs
neural crest
Neural crest cells give rise to variety of structures including some bones and cartilage of skull
have heart with at least 2 chambers, red blood cells with hemoglobin, and kidney

Question 8

Vertebrates

Answer 8

Craniates with a backbone
have the following derived characters
-vertebrae enclosing a spinal cord
-elaborate skull
fin rays, in aquatic forms

Question 9

neural crest

Answer 9

collection of cells near dorsal margins of the closing neural tube in an embryo

Question 10

Chephalaspidomorphi

Answer 10

Lampreys represent oldest living lineage of vertebrates

jawless vertebrates inhabiting various marine and freshwater habitats

Question 11

Gnathostomes

Answer 11

Vertebrates with jaws
outnumber jawless vertebrates
enlarged forebrain - enhanced smell and vision
In aquatic, lateral line system is sensitive to vibrations

Question 12

Chondrichthyes

Answer 12

Have skeleton composed of cartilage
-evolved secondarily from an ancestral mineralized skeleton
largest and most diverse group includes sharks, rays, and skates
shark eggs are fertilized internally but embryos can develop in different ways

Question 13

oviparous

Answer 13

eggs hatch outside mother’s body

Question 14

oviviparous

Answer 14

embryo develops within the uterus and is nourished by the egg yolk

Question 15

Viviparous

Answer 15

embryo develops within the uterus and is nourished through a yolk sac placenta from the mother’s blood

Question 16

Osteichthyes

Answer 16

includes bony fish and tetrapods
nearly all have bony endoskeleton
fishes
most fish breathe by drawing water over gills protected by an operculum
fishes control buoyancy with an air sac known as a swim bladder

Question 17

Class Sarcopterygil

Answer 17

lobe-fins have muscular pelvic and pectoral fins
include coelacanths, lungfishes, and tetrapods
transitional fossils
fins shifting to legs
gills to lungs