BG5/6 Flashcards
what are choanoflagellates (taxonomic rank)
taxon within the opisthokonta with fungi
poriferan special features
- ECM - metazoan specific molecule
- have actin-myosin cell contraction, muscles?
- gametes are formed from choanocytes and archeocytes
- Sclerocytes make spicules which provide defence and structure
what are placaoza - describe
bilayer of differentiated, ciliated cells, with a dorsal epithelium, cavity and vague mesenchymal/glya layer.
porifer cleavage
undefined
placazoa cleavage
?
porifera larval development
indirect
placozoan larval development
?
placazoan and porifera symmetry and coelom?
no
ctenophores special features
- coloblast structures
- specailised cells ctene/cone
- aplical sense organ: concentration of ganglia
- united mouth and anus
cnidaria special features
- symmetrical? radial, anthosoas,
- Neuroblast cells, which have neurocysts and barbs, defence and attack.
- mesoglea - sort of mesenchymal stuff, jelly like between ectoderm and gastroderm
lca metazoa described
colonial ball
with dorsal ventral axis
placazoa like creature with gastrulation and mesoderm.
ctenophore cleavage
undefined
cniderian cleavage
unilateral
larval development ctenophore
direct
larval development cnidarian
indirect
ediacara fauna what are they
kimbrella - most sophisticated
dickinsonia
mawsonites
what are the ediacra
hypothesis
- seperate clade vendobiota
- terrestrial lichen, not marine at all
- diploblast world = early diploblasts * fave
- mollusc like creature, barnacel (not kimbrella)
acoela cleavage
spiral, differs from lophotrochozoa spiral
special feautres acoela
gut filled with parenchymal cells
no ECM
lca eumetazoa mesoderm?
probs yes? says no, but acoela is yes. probs lost in xenoturbella
acoela brain?
yes
xenoturbella brain?
no
ecdysozoa cleavage
not spiral
ecdysozoa development
direct, shed cuticle
lophotrochozoa larvae
trochophores
lophotrochozoa
protosomes
schizcoely
mouth first.
doushantou ??
hypothesis
- big bacteria related on guilf - but nuclear envelope?
- volvocine algae - get smaller as divide
- holozoan protist, form spores
- worm like thing - has everything; pharynx, mouth, anus, coelom, gut, bilateral symmetry. inorganic?
cambrian explosion
525 mya
burgess shale fossils
lagerstatte fauna
like lophotrochozoa but couldnt be indentified into an extant phyla
wiwaxia, haeikiera, odontogriphus
distance calibtrated by fossils porifera and eumetazoa
750mya
distance by fossils for cnidaria and bilateria
690mya
distance fossils deuterostomes and lophotrocozoa
650mya
