Concept 1: Analyzing the diversity of animals (Ch 26, 32, 33, 34)Holtz: pg. 186-197

A glimpse into… Developmental Biology

What DEFINES an animal?

What DEFINES an animal?

Animals (Metazoa):MulticellularHeterotrophic (consumers)Eukaryotes (…not prokaryotes)Tissues develop from embryonic layers

Cell Structure and Specialization

Unique to Animals:No cells walls

Instead: separate structures (desmosomes, gap junctions, and/or tight junctions) hold cells together

Muscle and nervous tissue

Reproduction and Development

Primarily sexual (but some asexual) Sperm and egg

Zygote grows by many mitotic divisions Called cleavage Zygote to blastula to gastrula (usually in egg)

Gastrulation: http://www.youtube.com/watch?v=1MnwHRURKns http://www.youtube.com/watch?v=j87y7EAj8qE http://www.youtube.com/watch?v=8v6cXkzlEQA

Larva to adult by metamorphosis Same gene to regulate expression (Hox gene)

Body Plans

Useful for categorization

SymmetryTissuesBody CavitiesProtosome vs Deuterosome development

Symmetry

“no” symmetry Poriphera

Radial Symmetry All parts radiate from the centre Cnidaria

Bilateral Symmetry Distinct anterior (head-end), posterior (tail-end), left, right, dorsal

(top), ventral (bottom) Some have cephilization

Sensory organs and central nervous system in the head end Good for unidirectional movement

Symmetry

Porife Cnida Platy Nem Annel Mollu Arthr Echin Chor

No R?

Rad -ial

Bilateral

Larva: Bilateral

Adult: Radial

Classed as Bilateral animal, BUT radial symmetry as adult

Types of Tissue Layers

Tissue: Group of specialized cells

Diploblastic – two layers (radial animals: Cnideria … and Porifera… kinda) 1) Ectoderm

outer body cover (and nervous) 2) Endoderm

Lines the “digestive tract” and associated organs

Triploblastic – three layers (all bilateral animals) 1) Ectoderm, 2) Endoderm 3) Mesoderm

Muscles and other organs Development: http://www.youtube.com/watch?v=8v6cXkzlEQA Human Development:http://www.youtube.com/watch?v=UgT5rUQ9EmQ

Types of Tissue Layers

Porife Cnida Platy Nem Annel Mollu Arthr Echin Chor

Rad -ial

Bilateral

Diploblasti

Triploblastic

Body Cavities

Coelom – fluid filled body cavity separating the digestive tract from the outer body Acoelomates – no cavity at all

(Porifera, Cnideria,) Platyhelminthes Pseudocoelomates – animals with a cavity, but not all from

mesoderm Organs held in place loosely Nematoda

Coelomates – animals with a “true” Coelom (lined with mesoderm)

Organs suspended in order Annelida, Mollusca, Arthropoda, Enchinodermata,

Chordata

Body Cavities

Porife Cnida Platy Nem Annel Mollu Arthr Echin Chor

Some rad

Rad -ial

Bilateral

Diploblasti

Triploblastic

(No meso, so acoel…)

Acoelom

pseudo

Coelomate

Protostome vs Deuterostome

Protostome vs DeuterostomeProtostomes Deuterostomes

Cleavage

Coelom formation

Blastopore formation

Phyla

Protostome vs DeuterostomeProtostomes Deuterostomes

Cleavage spiral Radial

Coelom formation

Blastopore formation

Phyla

Protostome vs DeuterostomeProtostomes Deuterostomes

Cleavage spiral Radial

Coelom formation schizocoelous enterocoelous

Blastopore formation

Phyla

Protostome vs DeuterostomeProtostomes Deuterostomes

Cleavage spiral Radial

Coelom formation schizocoelous enterocoelous

Blastopore formation

Becomes mouth Becomes anus

Phyla

Protostome vs Deuterostome

Porife Cnida Platy Nem Annel Mollu Arthr Echin Chor

Some rad

Rad -ial

Bilateral

Diploblasti

Triploblastic

(No meso, so acoel…)

Acoelom

pseudo

Coelomate

Protostomes Deuterostom

Question...

An animal with anterior, posterior, dorsal, and ventral surfaces on its body must exhibitA) Protostomic development

B) Coelomate development

C) Segmentation

D) Radial symmetry

E) Bilateral symmetry

Question...

An animal with anterior, posterior, dorsal, and ventral surfaces on its body must exhibitA) Protostomic development

B) Coelomate development

C) Segmentation

D) Radial symmetry

E) Bilateral symmetry

Reminder…

Field/Lab Notebook Project starts on FRIDAY withWalk Through the Animal Phyla

Now…

Try #2 -10, 14, 34 – 40 in Holtzclaw