Ch. 34: Origin and Evolution of Vertebrates

Question 1

Chordates have

Answer 1

• Notochord

- Dorsal, hollow nerve cord

Question 2

Vertebrates

Answer 2

Chordates that have a backbone

Question 3

Gnathostomes

Answer 3

Vertebrates with jaws

Question 4

Tetrapods

Answer 4

Gnasthostomes that have limbs

Question 5

Amniotes

Answer 5

Tetrapods with terrestrially adapted egg

Question 6

Mammals

Answer 6

Amniotes that have hair and produce milk

Question 7

Humans

Answer 7

Mammals that have large brain and bipedal locomotion

Question 8

3 main phyla of Deuterostomes

Answer 8

1) Chordata => A) Cephalochordata and B) Vertebrata and Urachordata
2) Hemichordata => off of Ambulacaria
3) Echinodermata (Ambulacraria) => A) Echinoderms and B) Hemichordates

Question 9

Types of Echinodermata

Answer 9

• Sea Stars
• Sea Urchin
• outward 5-fold symmetry

Question 10

Explain how the Hemichordata exhibit characteristics of both Echinodermata and Chordata
- an intermediate group

Answer 10

• Similar to chordates because of pharyngeal gill slits

- Similar to Echinoderms because of their larval morphology and sequence data

Question 11

3 main phyla of Chordates

Answer 11

1) Cephalochordata (lancelets)
2) Urochordata (tunicates and sea squirts)
3) Vertebrata (Craniata)

Question 12

Most vertebrates contain

Answer 12

1) Bony cranium
2) Vertebral Column
include fish, amphibians, reptiles, birds, mammals

Question 13

“Fish” group contains

Answer 13

4 distinct groups of aquatic vertebrates

1) Hagfish
2) Lampreys
3) Cartilaginous fish
4) Lobe-finned fish

Question 14

Agnatha

Answer 14

without jaws

i.e. Sea Lamprey and Hagfish

have tooth analogs

Question 15

Osteichthyans (Lung fish)

Answer 15

closest relatives are tetrapods (include amphibians, lizards, turtles, crocodilians, birds, mammals)

Question 16

Amphibians have

Answer 16

an aquatic larval form and terrestrial adult form

Question 17

Amniotes

Answer 17

i. e. lizards, snakes, crocodiles, birds, mammals

- have an amniotic egg, permitting movement into dry, terrestrial habitats

Question 18

Mammals are covered

Answer 18

with hair and feed their young milk from mammary glands

Question 19

2 synapomorphies that define Echinodermata

Answer 19

1) Radial symmetry (pentamerous)

2) Water Vascular system

Question 20

Function of a Water Vascular System

Answer 20

• power, move with tube feet
• ampulla that holds water/ attached to tube feet
  that can help suction an organism to a particular location

Question 21

Why are cephalochordates, Urochordates, and Vertebrates all in the same taxon

Answer 21

Taxon: Phylum Chordata

1) Notochord (at some point in their lifetime
2) Pharyngeal Gill pouches (slits)
3) Dorsal Hollow Nerve Tube (Spinal Cord)
4) Post anal tail:
- Rod of vacuolated cells
- Gills or other structures (pharyngeal arches)
- Found above notochord, dorsal
- Muscular

Question 22

8 trends in vertebrate evolution and how/where each is seen in the phylogenetic tree

Answer 22

1) Vertebrae and Cranium: between Craniates and Vertebrates
2) Jaws: saw with agnatha and gnathostomes
3) Bony Endoskeleton: osteichthyans
4) Tetrapod Limbs: Amphibians
5) Amniotic Egg: Reptiles
6) Feathers and Scales: Reptiles
7) Lactation and fur: Mammals
8) Parental Care: Mammals

Question 23

draw an amniotic egg and explain its adaptive significance

Answer 23

1) embryo in center
2) amnion with amniotic fluid surrounding embryo
3) yolk sac: provides nutrients
4) allantois: collects waste products (NH3 and uric acid) and exchange membrane
5) Chorion: outer membrane before the shell
6) Shell possible
7) Albumin/ H2O: in between shell and chorion

Question 24

What do birds and mammals have in common?

major differences?

Answer 24

Common: 4 chambered heart/ feet and legs

Birds:

• feet/legs are scales
• hollow bones
• feathers
• no teeth

Mammals

• Mammary glands
• Hair
• Heterodont dentition

Question 25

Chondrichthyes

Answer 25

• cartilaginous skeleton
• maintained through life, mineralized and bone secondarily lost
• buccal pumping or ram ventilation depending on species (sharks)
• 2-chambered heart

Question 26

Osteichthyes

Answer 26

• bony fishes - thin scales
• mineralized skeleton
• swim bladder
• lateral line system
• operculum (or gills)
• 2- chambered heart

Question 27

Amphibia

Answer 27

• legs
• cutaneous respiration
• lungs - simple, buccal pump
• pulmonary veins
• 3-chambered heart

Question 28

Reptila

Answer 28

• amniotic egg - not tied to water
• dry skin - thick keratinized epithelium
• thoracic breathing
  
  • negative pressure ventilation
  • sencondary/ soft palate

Question 29

Aves

Answer 29

birds

• Endothermy
• Feathers & Flight
• Hollow bones
• 4-chambered heart
• parabronc

Question 30

Mammalia

Answer 30

• Hair
• Mammary glands
• Endothermy
• Heterodont dentition
• Nails, hooves, antlers
• carnivore, omnivore, herbivore GI systems
• egg-laying, marsupial, placental