Chordata

Question 1

The water flow of Amphioxus is

Answer 1

1. oral cirri that draws water in by the beating of cilia on the wheel organ
2. Pharynx (inside bag)
3. Gill slits
4. Atrium (outside bag)
5. Atriopore

Question 2

Velum in Amphioxus functions to

Answer 2

regulate the amount of water present

Question 3

The food pathway of Amphioxus is

Answer 3

1. oral cirri
2. gill bars (covered with mucous produced by endostyle)
3. cilia on epibranchial groove moves food back into esophagus
4. midgut
5. liocolon ring contracts to move food back
6. anus

Question 4

Member of subphylum Vertebrata is

Answer 4

ammocoetes

Question 5

ammocoetes are also known as

Answer 5

larval lamprey

Question 6

Ammocoetes are anadromous meaning that

Answer 6

they are larvae the develop in fresh water and move to the ocean when mature

Question 7

Ammocoetes have no more than ____ gill bars

Answer 7

7

Question 8

Ammocoetes don’t need oral cirri because

Answer 8

they are filter feeders

Question 9

Ammocoetes have what instead of atriopores?

Answer 9

external gill slits

Question 10

In contrast to Amphioxus, Ammocoetes have (3)

Answer 10

true 2-chambered hearts
lamellae on their gill bars
and liver, eyes and brain

Question 11

In contrast to Ammocoetes, Amphioxus have (3)

Answer 11

wheel organs
oral cirri
gonads

Question 12

The water pathway of Ammocoetes

Answer 12

1. oral hood
2. flaps on velum beat water into pharynx
3. internal gill slits
4. gill pouches
5. external gill slits and out the body

Question 13

The food pathway of Ammocoetes

Answer 13

1. oral hood
2. food particles trapped from mucous produced by sub pharyngeal gland
3. ciliary action of the mid-ventral ciliated ridge and mid-dorsal ciliated ridge move food back to esophagus
4. intestine
5. anus

Question 14

To tell the difference between Ammocoetes and Amphioxus slides

Answer 14

Ammocoetes- have no cirri

Amphioxus - have many more gill bars and have noticeable dark gonads/testes