Gnathostomata

Question 1

Gnathostomata

Answer 1

jawed fish

Question 2

features of Gnathostomata

Answer 2

• jaws and mineralised skeleton
• scales and teeth
• paired fins
• lateral line
• single circulation

Question 3

Gnathostomata mineralised skeleton

Answer 3

Started as dental elements in the head
might be cartilage infused with minerals
skeleton, teeth, and skull derived vertebrate forms

Question 4

Lateral line system

Answer 4

hearing the movement of another species in the water column through pores in the lateral line, which receive vibrations and operate on neuromasts

Question 5

Gnathostomata single circulation

Answer 5

blood flows in one constant circle

Question 6

what do fish have to prevent gills from blowing out?

Answer 6

Bulbus arteriosus, or conus arteriosus in sharks
- reduces pressure of blood pumping from heart to gills

Question 7

Chondrichthyes

Answer 7

Cartilaginous fish
Sharks

Question 8

Chondrichthyes characteristics

Answer 8

• heterocercal caudal fin
• ventral mouth
• placoid scales
• cartilaginous endoskeleton
• 5-7 pairs of gills
• no operculum
• no swim bladder

Question 9

Shark ampullae of Lorenzini

Answer 9

pores in the snout that detect electrical currents in the water

Question 10

Shark teeth

Answer 10

continually lost and replaced, homologous to placoid scales

Question 11

Shark scales

Answer 11

placoid scales
harden skin scales made from enamel and dentine