Lab Quiz One: Protochordates to Lamprey

Question 1

Amphioxus

Answer 1

Lancelet.
Cephalochordata.

Question 2

Rostrum

Answer 2

Snout projection.
(Cephalochordata).

Question 3

Buccal (oral) cirri

Answer 3

Filament-like appendages surrounding the mouth. Forms a sieve for filter feeding.
(Cephalochordata).

Question 4

Myomeres

Answer 4

Muscle segments arranged in a series along the body.

Question 5

Notochord

Answer 5

Dorsal midline structure that provides support and signals nervous and skeletal development. Made of cartilage.

Question 6

Dorsal hollow nerve cord.

Answer 6

Hollow tube of nervous tissue running down dorsal midline. Derives from ectoderm.

Question 7

Wheel Organ

Answer 7

Specialized structure in the mouth of a lancelet that helps clean the mouth by creating a vortex of water
(Cephalochordata).

Question 8

Pharynx.

Answer 8

Canal immediately behind the mouth and before the esophagus.

Question 9

Gill bars

Answer 9

Bars separating the pharyngeal gill slits.

Question 10

Phylum Chordata has…

Answer 10

1. DHNC
2. Notochord
3. Muscular post anal tail
4. Pharyngeal gill slits
   ALL AT ONCE

Question 11

Non-chordate deuterostomes

Answer 11

Echinodermata
Hemichordata

Question 12

What kind of circulatory system does Echinodermata have?

Answer 12

Open

Question 13

What is the body symmetry of Echinodermata?

Answer 13

Radial

Question 14

That does the Echinodermata nervous system have?

Answer 14

Nerve nets.
Peripheral ganglia.

Question 15

Does Echinodermata have a tri-partite brain?

Answer 15

No.

Question 16

Does Echinodermata have any of the chordate characteristics?

Answer 16

No.

Question 17

What does Hemichordata mean? Why do they have this name?

Answer 17

Half-chordate. Have pharyngeal gill slits and a short DHNC.

Question 18

What are the Hemicordate body regions?

Answer 18

1. Proboscis
2. Collar
3. Trunk

Question 19

What type of circulatory system do Hemichordates have?

Answer 19

Open.

Question 20

What subphylums make up Protochordates?

Answer 20

1. Urochordata (sea squirts, tunicates)
2. Cephalochordata (lancelet)

Question 21

Describe Urochordata.

Answer 21

1. Marine filter feeders (endostyle to trap food).
2. MOTILE larvae with all chordate characteristics.
3. Sessile adults lack chordate characteristics, but gill slits are retained.

Question 22

Describe Cephalochordata.

Answer 22

1. Segmented muscles.
2. Filter feeders (sensory hood with buccal cirri).
3. Retain all four chordate characteristics into adulthood.

Not vertebrates yet!

Question 23

Describe Craniata.

Answer 23

Possess a DISTINCT MINERALIZED SKULL.

Not all vertebrates. Have chordata characteristics. Have neural crest.

Question 24

In what clade does the first duplication of HOX genes occur?

Answer 24

Craniata.

Question 25

Describe neural crest cells.

Answer 25

1. Arise from ectoderm 2. Embryonic tissue near developing neural tube. 3. Forms structures like melanocytes, craniofacial cartilage/bone, smooth muscle, glia.

Question 26

Describe the HOX gene complex.

Answer 26

Group of developmental genes. Duplications correlate with increased complication of body plan. Outline body plan anterior to posterior.

Question 27

How many semicircular canals do hagfish have?

Answer 27

1 pair (2 total).

Question 28

How many semicircular canals do lamprey have?

Answer 28

2 pairs (4 total).

Question 29

Describe Myxiniformes.

Answer 29

Hagfish. - 1 pair of semicircular canals - aganathan, cyclostomus - HOXX gene duplication - Scavengers - Segmented muscles apply force to notochord for movement - begin to see organs - NOT vertebrates

Question 30

Describe subphylum Vertebrata.

Answer 30

1. Have vertebrae (most serially arranged column) 2. At least 2 pairs of semicircular canals. 3. DHNC -> spinal cord 4. Notochord -> vertebral dics (cartilage) 5. Dual nervous system (somatic and visceral branches)

Question 31

Describe order Petromyzontiformes.

Answer 31

Lamprey - Ture vertebrates - Possess precursors of vertebrae (arcualia, vertebral arches) - agnathan, cyclostomus - 2 pairs semicircular canals - parasitic - larvae called ammocoetes

Question 32

What are lamprey larvae called?

Answer 32

ammocoetes

Question 32

What are the precursors of vertebrae?

Answer 32

Arcualia (vertebral arches)

Question 32

What kind of skeleton do lamprey have?

Answer 32

Cartilaginous.

Question 32

Myosepta

Answer 32

CT fascia that separates adjacent myomeres.

Question 33

What is the lamprey's mouth cartilage called?

Answer 33

Annular cartilage.

Question 34

What cartilaginous structure lies below the pharyngeal gill slits in lamprey?

Answer 34

Branchial basket.