Topic 26: Introduction to Chordates

Question 1

Phylum Chordata

Answer 1

Bilarerian animals that belong to Deuterostomia, vertebrates and invertebrates, segmented.

Question 2

Notochord

Answer 2

Longitudinal flexible rod located dorsally between the digestive tract and the nerve cord and provides skeletal support. Develops from mesoderm

Question 3

Dorsal, Hollow Nerve Cord

Answer 3

Develops from a plate of ectoderm during embryonic development, unqiue to chordates (others have solid nerve cords)

Question 4

Pharyngeal Slits

Answer 4

Slits that open to the outside of the body, function as filter-feeding structures, gas exchange, and muscle elements in the head.

Question 5

Muscular Post-Anal Tail

Answer 5

Provides propulsive force.

Question 6

Lancelets (Cephalochordata)

Answer 6

Superficially resemble fish, sedentary suspension feeders.

Question 7

Tunicates (urichordata)

Answer 7

Living sister taxa of vertebrates, filter-feeders, sessile, larval stage shows chordate traits.