Vertebrates

Question 1

Amphibians

Answer 1

3 clades:

• Salamanders
• Frogs
• Caecilians

Question 2

Salamanders

Answer 2

• Amphibians without tails

- Some aquatic, some terrestrial

Question 3

Caecilians

Answer 3

• Legless, nearly blind, resemble earthworms

- Absence of legs is a derived trait evolved from vertebrates with legs

Question 4

Cuticular respiration

Answer 4

Gas exchange through the skin

Question 5

Amniotes

Answer 5

• Tetrapods that have a terrestrially adapted egg
• Reptiles, birds, mammals
• Amniotic egg was key adaption to life on land
• Relatively impermeable skin

Question 6

Reptiles

Answer 6

• Scales create waterproof barrier
• Most lay shelled eggs on land
• Ectothermic (absorb external heat)

Question 7

Birds

Answer 7

• Archosaurs
• Almost all anatomy has undergone modification in their adaption to flight
• Lack of urinary bladder
• No teeth

Question 8

Mammals

Answer 8

• Amniotes that have hair and produce milk
• Endothermic
• Large brain
• Did not undergo adaptive radiation until after the Cretaceous

Question 9

Characteristics of Chordates

Answer 9

(Bilaterian animals, all vertebrate)

• Notochord
• Dorsal, hollow nerve cord
• Pharyngeal slits
• Post-anal tail

Question 10

Notochord

Answer 10

Rod between digestive tube and nerve chord

-Provides skeletal support

Question 11

Pharyngeal Slits/Clefts

Answer 11

Filter-feeds
Gas exchange
Develop into parts of ear, head and neck in tetrapods

Question 12

Post-anal Tail

Answer 12

• Greatly reduced during embryonic development

- Provides propelling force in aquatic species

Question 13

Hox-Genes

Answer 13

Control organismal development

-Critical for proper development