Lab 1 (Basal Chordates) Amphioxus

Question 1

rostrum

Answer 1

anterior tip of the animal

Question 2

buccal cirri

Answer 2

keep large particles from entering the pharynx

may contain taste discriminating elements

Question 3

wheel organ

Answer 3

creates a vortex of water current into pharynx

Question 4

nerve cord

Answer 4

part of the nervous system

Question 5

notochord

Answer 5

enhances the overall rigidity of the body

Question 6

eyespot (frontal eye pigment)

Answer 6

a sensory organ of light intensity

Question 7

photoreceptors (ocellus and ocelli)

Answer 7

photoreceptors

Question 8

dorsal fin

Answer 8

NONE

Question 9

myomeres

Answer 9

muscles mostly for locomotion

Question 10

hepatic diverticulum (midgut, cecum or midgut diverticulum)

Answer 10

production of some digestive enzymes

homologous to liver/pancreas in human

Question 11

atrium

Answer 11

body chamber housing the organs

Question 12

intestine / hindgut

Answer 12

digests food

Question 13

anus

Answer 13

poop center

Question 14

pharangeal bars and slits

Answer 14

ciliated lining of the bar traps food and moves it dorsally towards the intestine

Question 15

epibranchial groove

Answer 15

pathway for food particles to be transported from pharynx to gut

Question 16

ovaries and testis

Answer 16

reproductive gametes

Question 17

endostyle

Answer 17

produces mucous lining of the pharnyx to trap particles

also binds iodine and produces iodine compounds

homologous with the endostyle in urochordates ad the thyroid gland in higher vertebrates