Week 2.1

Question 1

primitive vertebrates

Answer 1

larger than non-vert chordates

Question 2

what do verts have that chordates don’t

Answer 2

faster organ systems
increased predation
protective intergumentary systems

Question 3

what was first to change between vertebrates and chordates

Answer 3

respiration

Question 4

brain of cephalochordates

Answer 4

Notochord extends to tip
No cranium
No special sensory organs
Simple brain and ‘eye’

Question 5

brain of verts

Answer 5

Head extends beyond notochord
Has a cranium
Tripartite brain
Complex sensory organs

Question 6

excretion of cephalochordate

Answer 6

No special kidney
Internal Coelom filtered by solenocytes via negative pressure
Filtrate moved to atrium and expelled
Body fluids same composition as sea water

Question 7

excretion of verts

Answer 7

Glomerular kidneys
Ultra-filtration of blood
Filtrate moves into archinephric ducts
Fluid more dilute than seawater; kidney used for volume and divalent cation regulation

Question 8

is there a fourth germ layer

Answer 8

NO