transition

Question 1

what do lepidotrichia strengthen?

Answer 1

fins by providing support

Question 2

do bony fish have a spiral valve?

Answer 2

no only in extinct forms

Question 3

what type of scales do bony fish have?

Answer 3

cycloid, ctenoid or absent

Question 4

fleshy finned fish (sacroptergyii)

Answer 4

• fins at the end of short projecting appendages
• used for maneuvering in water

Question 5

sacropterygii fins

Answer 5

• diphycercal tail, three-lobed in coelacanths
• lobe-fins with bony leg-like supports

Question 6

bony elements of paired fins

Answer 6

• modified for support and movement underwater
• on land same function
• bony elements of fins of lobe finned fishes resemble homologous structures of amphibians

Question 7

evolved adaptations to air breathing

Answer 7

• increased vascularization of the air-filled cavity
• double circulation to direct deoxygenated blood into the oxygenated blood out of the lungs to the other body tissues