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