topic 12 Flashcards
Animal cell structure
multicellular eukaryotes
lack cell wall
ECM
collagen
ability to move
animals are:
Chemoheterotrophes
Homeobox genes
Genes that regulate anatomical development
regulate morphogenesis
in all eukaryotes
Hox Genes
Subset of homeobox genes
regulate body axes and structures during embryonic development
direct development vs indirect
Direct :embryo continues to adult form
Indirect: embro has intervening stage(larvae)
Embryonic development
zygot undergoes mitotic divisions –> cleavage, which turns to blastula(hollow) which undergoes invagination and turns into da gastula(several germ layers)
protostome
first invagination turns to mouth
spiral cleavage, determinate
booty hole second
deutrostome
second invagination turns to mouth
radial cleavage, indeterminate(can lead to twins),
booty hole first
Eumatozoan design
true tissue(are isolated from other tissues w membrane)
animal common ancestor
colonial flagellate
Germ layers (endoderm vs ectoderm vs mesoderm)
Endo: digestive system, organs
ecto :skin and nerves,
meosderm: muscles and shi
Radiata vs bilateria (hint germ layers)
Radiata: diploblastic
bilateria: triploblastic
Phylum Polifera(spongy)
lack hox genes
sessile(except larvae)
do not go through onogatomy(idk some shit that starts with O)
no symmetry
suspension feed
hermadaphrodites
Spicules
spongin
cyanocytes and amoebocytes(specialized cells in sponge)
cyanocytes :flagellated for stream, sperm arises from
amoebocytes :move nutrients between cells, eggs arise from
Plylum cnideria(sting)
true tissues
Organs
diploblastic
carnivorous
cnidocytes: sting cells
Polyp vs medusa(cniderian forms)
polyp: sessile
medusa: motile
common ancestors resembled __________ how did they resemble animals
-choanoflagellates
1)Cell morphology
2)Cell morphology to animal cells
3)DNA sequence homology
advantage of multicellularity
-specialized cells
-coordination among cells
Microvilli(choanoflagellates)
fingerlike projections of cell membrane
Mesohyl(ponifera)
Gelatinous acellular layer
what are spicules
spiky support in sponge
what is spongin
collagen support in ponifera