Animal Evolution Chpt. Animal Evolution Chpt. 3232
MulticellulaMulticellularr
MulticellularMulticellular
Heterotrophic Heterotrophic digest digest within bodywithin body
MulticellularMulticellular
HeterotrophicHeterotrophic
Eukaryotic, no cell Eukaryotic, no cell wallwall
MulticellularMulticellular
HeterotrophicHeterotrophic
Eukaryotic, no cell Eukaryotic, no cell wallwall
Specialized cellsSpecialized cells
MulticellularMulticellular
HeterotrophicHeterotrophic
Eukaryotic, no cell Eukaryotic, no cell wallwall
Specialized cellsSpecialized cells
Dominant diploid Dominant diploid stage, sexual stage, sexual reproductionreproduction
MostMost, capable of , capable of locomotionlocomotion at some at some point in lifetime.point in lifetime.
Most capable of Most capable of locomotionlocomotion
Most have Most have nerve cellsnerve cells and and muscle cellsmuscle cells -> ->
respond respond & move& move
Large nonmotile egg (n) +
small flagellated sperm (n) =
ZYGOTE
Sexual Sexual ReproductionReproduction
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 urchin
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
fills the blastocoel (cavity)
produces layers of tissue
Gastrulation- process during
which three germ layers form
http://www.youtube.com/watch?v=8v6cXkzlEQA&feature=related
Gastrula
ectodeectodermrm
EctodermEctoderm becomesbecomes: outer : outer covering, covering, nervous system nervous system
EndodermEndoderm becomesbecomes: : digestive tractdigestive tract
MesodermMesoderm becomes: becomes: muscles, muscles, bloodblood
QuickTime™ and a decompressor
are needed to see this picture.
Genes that direct development of major body parts in an animal … provide positional information
Impact morphology of the organism
Transformation of a zygote to an animal of specific form is
controlled by:
Origin of animals from a flagellated
protist??
Parazoa - Eumetazoa -
Parazoa - no
tissues
Parazoa - no
tissues (function like colonial protists)
Parazoa - no
tissues (function like colonial protists)
Parazoa - Eumetazoa -
Eumetazoa - have
true
tissues
Eumetazoa - have
true
tissues
Eumetazoa true
tissuesarrangement of body symmetry
Eumetazoa true
tissues
Radial Symmetry
arrangement of body structure
Receives stimuli from all directionsall parts radiate all parts radiate from centerfrom center
QuickTime™ and a decompressor
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Eumetazoa true
tissues
Radial Symmetry
Bilateral Symmetry
arrangement of body structure
Cephalization
What is the evolutionary advantage of cephalization???
Eumetazoa
Bilateral Symmetry
Type of body cavity
Eumetazoa
Bilateral Symmetry
Acoelomate
Type of body cavity
no body cavity between digestive cavity & outer body wall no tube outside of a tube
Eumetazoa
Bilateral Symmetry
Acoelomate
Body cavity
Type of 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
Eumetazoa
Bilateral Symmetry
Pseudocoelomate
Differences in pattern of early development
Eumetazoa
Bilateral Symmetry Coelomate
Differences in pattern of early development
Eumetazoa
Bilateral Symmetry Coelomate
Protosomes
Differences in pattern of early development
Eumetazoa
Bilateral Symmetry Coelomate
ProtosomesDeuterosto
mes
Differences in pattern of early development
1. Pattern of cleavage
2. Coelom formation
mesoderm stays connected forming coelom
mesoderm splits forming coelom
2. Coelom formation
Top view - deuterostomes
2. Coelom formation
protostome
3. Blastopore “fate”