animal evolution chpt. 32. multicellular multicellular heterotrophic digest within body

Animal Evolution Chpt. Animal Evolution Chpt. 3232

MulticellulaMulticellularr

MulticellularMulticellular

Heterotrophic Heterotrophic digest digest within bodywithin body


HeterotrophicHeterotrophic

Eukaryotic, no cell Eukaryotic, no cell wallwall




Specialized cellsSpecialized cells




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

expands

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

Gastrula

ectodeectodermrm

EctodermEctoderm becomesbecomes: outer : outer covering, covering, nervous system nervous system

endodermendoderm

EndodermEndoderm becomesbecomes: : digestive tractdigestive tract

mesodermmesoderm

MesodermMesoderm becomes: becomes: muscles, muscles, bloodblood

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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 -

Parazoa - Eumetazoa -

Parazoa - no

tissues

Parazoa - no

tissues (function like colonial protists)

porifera

Parazoa - Eumetazoa -

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

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Eumetazoa true

tissues

Radial Symmetry

Bilateral Symmetry

arrangement of body structure

Cephalization

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

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



Eumetazoa


Protosomes


Eumetazoa


ProtosomesDeuterosto

mes


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”

animal evolution chpt. 32. multicellular multicellular heterotrophic digest within body

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