Ch 2 Origin of Chordates

Question 1

Synapomorphies of Deuterostomia; contains Ambulacraria and Chordata

Answer 1

Cleavage is non-spiral and indeterminate.
Blastopore becomes, or is near the site of formation of, the anus.
The coelom is an enterocoel.
Larva has a loop-shaped ciliated band used for locomotion.

Question 2

SOC grow laterally from the pharynx and often open to the surface as pores or slits.

Answer 2

Pharyngeal pouches

Question 3

SOC A groove on the pharyngeal floor or a gland derived from part of the endostyle.

Answer 3

Endostyle groove/Thyroid gland

Question 4

SOC A stiff, longitudinal rod of turgid cells along the dorsal part of the body

Answer 4

Notochord

Question 5

SOC A single long nerve dorsal to the notochord.

Answer 5

Tubular nerve cord

Question 6

SOC Larva or embryo have elongated ____________

Answer 6

muscular postanal tail.