Section 31.3 (Exam 3)

Question 1

What are the 3 main chordate synapomorphies?

Answer 1

Dorsal hollow nerve cord

Post-anal tail

Notochord

Question 2

What is a notochord?

Answer 2

A dorsal supporting rod that is rigid and flexible

Question 3

What is a post-anal tail?

Answer 3

a tail that extends beyond the anus

Question 4

What are lancelets also called?

Answer 4

cephalochordates

Question 5

What are some characteristics of lancelets, or cephalochordates?

Answer 5

Very small, less than 5 cm

Notochord is retained throughout life

Enlarged pharynx

Question 6

What does the enlarged pharynx form in lancelets?

Answer 6

forms a pharyngeal basket for filtering prey from the water

Question 7

What are tunicates also called?

Answer 7

urochordates or sea squirts

Question 8

What are some characteristics of tunicates/urochordates/sea squirts?

Answer 8

Adult body is enclosed in a tough “tunic” of proteins and polysaccharides secreted by the epidermis

Adults are sessile

Pharyngeal basket filters prey from the water (like lancelets)

Question 9

Why are they called tunicates?

Answer 9

Adult body is enclosed in a tough “tunic” of proteins and polysaccharides secreted by the epidermis

Question 10

In vertebrates, a __________________ replaces the notochord.

Answer 10

vertebral column

Question 11

Aside from a vertebral column, what are 4 additional features of vertebrates?

Answer 11

Anterior skull encloses a large brain

Rigid internal skeleton

Internal organs suspended in a coelom

Well-developed circulatory system driven by a ventral heart

Question 12

What functions do the features of vertebrates allow?

Answer 12

These features can support large, active animals, allowing vertebrates to diversify widely.

Question 13

What are the two groups of vertebrates?

Answer 13

Jawless fishes and jaw-mouthed fishes/gnathostomes

Question 14

What are the two groups of jawless fishes?

Answer 14

hagfishes and lampreys

Question 15

What are the two groups of jaw-mouthed fishes/ gnathostomes?

Answer 15

Bony vertebrates and chondrichthyans

Question 16

What are the two groups of bony vertebrates?

Answer 16

Ray-finned fishes and lobe-limbed vertebrates

Question 17

What are the 4 groups of lobe-limbed vertebrates?

Answer 17

Coelacanths

Lungfishes

Amphibians

Amniotes

Question 18

What are some characteristics of hagfishes?

Answer 18

Marine, partial cranium, jawless

Cartilaginous skeleton, lacking vertebrae

Blind, large amounts of slime as defense

Question 19

What are some characteristics of lampreys?

Answer 19

Complete skull and vertebrae (cartilaginous)

Many species are parasitic

Round mouth used to attach to fish and rasp at flesh, some adults are non-feeding

Live in freshwater or anadromous

Question 20

What does it mean to be anadromous?

Answer 20

live in saltwater, but breed in freshwater

Question 21

What are gnathostomes also known as?

Answer 21

jaw-mouths

Question 22

What are some advantages that gnathostomes have?

Answer 22

Jaws and teeth improved feeding efficiency and prey capture

Most jawed fishes have paired fins for stabilization and swimming

Question 23

What happened as a result of jaws and teeth improving feeding efficiency and prey capture?

Answer 23

Jawed fishes diversified rapidly and became dominant

Question 24

What are 4 types of chondrichthyans?

Answer 24

Sharks

Rays

Skates

Chimaeras

Question 25

What are some characteristics of chondrichthyans?

Answer 25

Skeletons of cartilage Flexible, leathery skin

Question 26

What are some characteristics of sharks?

Answer 26

Swim by using lateral undulations of the body Most are predators

Question 27

What are some characteristics of skates and rays?

Answer 27

Swim by vertically flapping enlarged pectoral fins Live on sea floor and feed on buried animals

Question 28

What is a characteristic of chimaeras?

Answer 28

Live in deep sea cold waters

Question 29

What material makes up the vertebrae of hagfishes, lampreys, and sharks?

Answer 29

cartilage

Question 30

What did one lineage of gnathostomes give rise to?

Answer 30

Bony vertebrates with internal skeletons of calcified, rigid bone

Question 31

What are some characteristics of ray-finned fishes?

Answer 31

Covered by scales Swim bladder for buoyancy Gills covered by operculum Exploit all types of food

Question 32

What is the function of the operculum?

Answer 32

Structure that covers and protects the gills Moves to enhance water flow over the gills

Question 33

Why are coastal waters and estuaries extremely important to marine fish?

Answer 33

This is where they go to lay eggs

Question 34

Some ray-finned fish are anadromous. Name one example of this and what it means.

Answer 34

Salmon are anadromous. They move from the ocean to the fresh water to breed.