Chapter 32 – Introduction to Animal Evolution
1. Characteristics of Animals
o
o

Bodies are held together by proteins (collagen) and intercellular junctions

Fertilization → cleavage → blastula → gastrula → larva → adult (metamorphosis!)
o
o
o Change from zygote to animal regulated by ______________ genes
2.
Define the following terms:
o Cleavage
o
Blastula
o
Gastrula
o
Larva
o
Metamorphosis
o
3. Animal Kingdom
o Developed from common ancestors (______________________) → colonial flagellated protist
o ___ animal phyla
o Label the diagram below of early embryonic development
o
o Views of animal diversity → 2 types

Traditional →

Molecular Systematics →
1
1.
Define the following terms with regard to animal body plans.
a. Grade
b.
Body plan
c.
Radial symmetry
d.
Bilateral symmetry
e.
Dorsal
f.
Ventral
g.
Anterior
h.
Posterior
i.
Cephalization
j.
Germ layers
k.
Endoderm
l.
Ectoderm
m. Archenteron
n.
Diploblastic
o.
Triploblastic
p.
Mesoderm
q.
Body cavity
r.
Coelom
s.
Pseudocoelomate
t.
Coelomate
Acoelomate
4. Traditional Phylogenic Tree
o Pg. 636
o Based on body plan
o 1st major split →
Parazoa →
Eumetazoa →
o Eumetazoa → divided into two branches
2
Radiata
Bilateria
Diploblastic →
Triploblastic →
o Germ Layers →

Ectoderm →

Mesoderm →

Endoderm →
5. Acoelomates, Pseudocoelomates, Coelomates
o Applies to triploblastic animals
o Acoelomates →

o Pseudocoelomates →

“_________________________________” body plan; fluid filled space separates
digestive tract from outer body wall

o Coelomates →

6. Function of coelom:
o 1.
o 2.
o 3.
7. Coelomates are divided into 2 grades: Protostomes and Deuterostomes
3
Protostomes
Deuterostomes
Schizocoelous –
Enterocoelous –
Cleavage
Coelom Formation
Fate of blastopore (opening)
label the following diagram
4
1.
Use the unlabeled diagram to compare and contrast protostomes and deuterostomes development.
2.
What is the difference between determinate cleavage, radial cleavage and indeterminate cleavage?
3.
What is the difference between schizocoelous and enterocoelous?
4.
What are the 5 points of agreement on animal phylogeny?
a.
b.
c.
d.
e.
8. Cambrian Explosion
o Burst of animal origins; ___________________ million years ago
o Hypothesis for what caused this explosion (diversification)

1. Ecological causes →

2. Geological causes →

3. Genetic causes →
5