Animal Evolution Chpt. 32
Multicellular
Multicellular
Heterotrophic digest within body
Multicellular
Heterotrophic
Eukaryotic, no cell wall
Multicellular
Heterotrophic
Eukaryotic, no cell wall
Specialized cells
Multicellular
Heterotrophic
Eukaryotic, no cell wall
Specialized cells
Dominant diploid stage,
sexual reproduction
Most, capable of
locomotion at some point in
lifetime.
Most capable of locomotion
Most have nerve cells and
muscle cells ->
respond & move
Large nonmotile egg (n)
+
small flagellated sperm
(n) =
ZYGOTE
Sexual
Reproduction
genetic diversity* genetic diversity * genetic diversity
mitotic divisions w/o cell growth
(cleavage)
cleavage
results in
multicellular
stage --->
blastula
end stage of
cleavage
zygote to blastula - sea
embryonic stem cells
human manipulation of
embryonic stem cells
one end of
the embryo
folds inward >
Gastrulation- layers of embryonic tissue that w/
develop into
body parts are formed
one end of
the embryo
folds inward >
Gastrulation- process during which three germ
layers form
expands
fills the blastocoel (cavity)
produces layers of tissue
http://www.youtube.com/watch?v=8v6cXkzlEQA&feature=related
Gastrulation-
process during which three germ
Gastrula
Gastrula
ectoderm
Ectoderm becomes:
outer covering,
nervous system
endoderm
Endoderm becomes:
digestive tract
mesoderm
Mesoderm becomes:
muscles, blood
QuickTime™ and a
decompressor
are needed to see this picture.
Transformation of a zygote to an animal of
specific form is controlled by:
Genes that direct development of major
body parts in an animal … provide positional
information
Impact morphology of the organism
Origin of animals from a
flagellated protist??
Parazoa -
Parazoa -
Eumetazoa
-
Parazoa no tissues
Parazoa no tissues
(function like
colonial
protists)
Parazoa no tissues
(function like
colonial
protists)
porifera
porifera
Parazoa -
Eumetazoa
-
Eumetazoa
have
true
tissues
Eumetazoa
have
true
tissues
Eumetazoa
true
tissues
arrangement of body
symmetry
Radial
Symmetry
Eumetazoa
true
tissues
arrangement of body
structure
Receives stimuli
from all directions
all parts radiate from center
QuickTime™ and a
decompressor
are needed to see this picture.
Radial
Symmetry
Eumetazoa
true
tissues
Bilateral
arrangement
of
body
Symmetry
structure
Cephalization
What is the
evolutionary
advantage of
cephalization???
Cephalization
Type of
body
cavity
Bilateral
Symmetry
Eumetazoa
Type of
body
cavity
Eumetazoa
Acoelomate
Bilateral
Symmetry
no body cavity between
digestive cavity & outer
body wall no tube outside of a tube
Type of
body
cavity
Eumetazoa
Acoelomate
Bilateral
Symmetry
Body cavity
Have body cavity
tube outside a tube
Have body cavity
tube outside a tube
Body cavity, not
completely lined
with mesoderm
Have body cavity mesoderm completely
surrounds
Eumetazoa
Bilateral
Symmetry
Coelomate
Body cavity,
completely lined
with mesoderm
Differences
in pattern of
early
development
Bilateral
Symmetry
Eumetazoa
Pseudocoelomate
Differences
in pattern of
early
development
Bilateral
Symmetry
Eumetazoa
Coelomate
Differences
in pattern of
early
development
Bilateral
Symmetry
Eumetazoa
Protosom
es
Coelomate
Differences
in pattern of
early
development
Eumetazoa
Protosom
Deuterostom
es
Bilateral es
Symmetry
Coelomate
1. Pattern of cleavage
mesoderm splits forming
coelom
2. Coelom formation
mesoderm stays connected
forming coelom
2. Coelom formation
Top view - deuterostomes
2. Coelom formation
protostome
3. Blastopore “fate”