Week 7 Flashcards
Patterns of organization (symmetry)
Asymmetry
Radial Symmetry (oral-aboral)
- biradial
-pentaradial
Bilateral symmetry (most complex animals)
- display cephalization
-dorsal/ventral plane, anterior/posterior plane)
Diploblastic organization
two embryonic tissue layers
- ectoderm (outer, epidermis)
-endoderm (inner, digestion)
separated by the mesoglea
Triploblastic organization
-ectoderm (outer, epidermis)
-endoderm (inner, digestion)
-mesoderm (bulk of body tissues)
Triploblastic organization (body cavities)
coelom: body cavity completely surrounded by mesoderm
Acoelomate
- Do not have a coelom
- Pretty much have no body cavities
Pseudocoelomate
- Have a body cavity but is not surrounded completely by mesoderm tissue
- Not a true coelom
- Flatworms
Coelomate
- More complex animals
- Have a true coelom
Protostomes vs Deuterostomes
Proto: spiral cleavage, blastophore develops into mouth, trocophore larvae, schizocoelous coelom
- spiral cleavage is division along diff axis/twists
Deutero: radial cleavage (aligns directly), blastophore develops into anus, enterocoelous coleom
protists are usually unicellular but that does not mean that they are ___
simple
what are the contractile vacuole, cytoproct and pellicle that we see in many protists
Contractile vacuole - regulates water content
Cytoproct: digestive waste products are eliminated
Pellicle: Consists of outer plasma membrane and a thin region of cytoplasm, high concentration of materials that allow a certain degree of rigidity - gives a particular shape
- Not all unicellular protists have this
- composed of microtubules
ways of asexual reproduction
binary fission (most common)
Schizogony: means to split
- Series of mitosis (nuclear divisions) not immediately followed by cell division
○ Produced a cell with lots of nuclei, later divides into multiple cells with identical nuclei
Budding
Important Protozoan groups
Excavata
-excavated feeding groove
-flagellated
-modified anaerobic mitochondria
-pathogens
Amoebozoa:
-use pseudopodia to feed/move
lack supporting structure
-amoeboid in shape
Rhizaria
Alveolata
-stacked vesicles
highly variable
plastids
dinoflagellates
Metazoa (basal animal phyla)
multicellular animals
are mobile (have contractile proteins)
apoptosis
process where cells strategically die
Phylum Porifera characteristics (sponges)
asymmetrical/radial symmetry
water filtration
no tissues or organs
spicules: supporting structures unique to these animals
evolutionary impacts of multicellularity
increased complexity
division of labour
morphological diversity
social behaviour/symbiotic relationships
Porifera basic body form
two cell layers - ponacocyte
choanocyte has microvilli to draw in water
reproduction of Porifera
asexual mostly: release gemmules (little balls of cells)
sexual: monoecious
