invertebrate chordates

Question 1

What is the function of the notochord?

Answer 1

flexible supportive rod that acts as site for muscle attachment

Question 1

What are the 5 main characteristics of all chordates?

Answer 1

1. post anal tail 2. notochord 3. dorsal nerve chord 4. endostyle or thyroid gland 5. pharynx (pharyngeal gills or pouches)

Question 2

what is the function of the pharyngeal slits?

Answer 2

gas exchange

Question 3

What is the function of the endostyle?

Answer 3

produces mucus and becomes the thyroid gland in vertebrates

Question 4

What is the function of the post-anal tail?

Answer 4

locomotion and balance

Question 5

How are pharyngeal grooves formed?

Answer 5

inpocketing of the ectoderm

Question 6

How are pharyngeal pouches formed?

Answer 6

outpocketing of the endoderm lining of the pharynx

Question 7

What are the 3 main subphyla of chordata?

Answer 7

vertebrates, urochordata, cephalochordata

Question 8

What are the distinguishing features of urochordata (tunicates)?

Answer 8

filter feeders that are sessile as adults but free swimming as larva, hermaphroditic, open circulatory system, adults only remain the pharyngeal slits of the common characteristics of chordates; larvae exhibit the rest

Question 9

What are the distinguishing features of cephalochordata (lancelets)?

Answer 9

larvae are free swimming while adults spend majority of time burrowed into sand, oral cirri for filter feeding, closed circulatory system, complete digestive system, excretion through nephirdia, segmented myomeres for muscles