Biol 108 final chapters 19,20,21 Flashcards
Animals are phylogenetically closer to..
Fungi because they are both in the opisthokont amorphea
Multicellular heterotrophs eukaryotes with tissue that originated from embryonic layers
Animals cell structure and specialization
Multicellular except for gametes
no cell wall
cells and tissues are connected by extracellular tissues
somatic cells differentiate
two cells special to animals
muscle cells form muscle tissue and nervous cell (neurons)
Animals mode of nutrition
chemoheterotrophs and the are also phagotrophic heterotrophs because they digest and ingest food internally
Animals reproduction
Usually sexual and they are diploid at all stages of life cycle
meiosis of haploid gametes that then come together and form a diploid zygote
egg large non motile and sperm motile small
asexual- budding (only invertebrate), fragmentation, binary fission, parthenogenesis (embryo from unfertilized egg)
Embryonic development
rapid mitotic division called cleavage completed at 8 cells
formation of multicellular blastula with hollow cavity called the blastocoel
Infolding forms gastrula pouch in archenteron opening called blastopore
Who has blastula and gastrulation phase
ONLY ANIMALS
Development is regulated by what in animals
Hox genes
Development postnatal ontogeny 2 types
direct development- ontogeny is divided from juvenile to adult stage
indirect development- ontogeny is divided into larval stage and juvenile stages bridged by metamorphosis
mobile during development
at least once
Body Plan
symmetry either radial or bilateral
tissues- integrated group of cells with common structures and functions
tissues come from embryonic layers
ectoderm- nervous system
endoderm-archenteron lines the development of the digestive tube
triploblastic has mesoderm- bones, organs and muscle tissues
Body cavity
only present in triploblastic fluid or air filled space between digestive tract and body wall
Haemocoel
forms from mesoderm and it is the primary body cavity, gives rise to blastocoel
circulates nutrients and waste
hydrostatic skeleton
secondary cavity
coelom- formed from mesoderm
coelomic fluids
forms structures and suspends internal organs
allows internal organs to deform such as the heart
hydrostatic skeleton
Lack body cavity
small flat animals that use diffusion to circulate nutrients and wastes
Protosome development
cleavage- spiral and determinate
coelom formation- schizocoely and this is the splitting of the mesoderm
fate of blastopore- mouth
Deutrosome development
cleavage- radial and indeterminate
coelom formation- enterocoely and this is budding off of mesoderm pouch from archenteron
Fate of blastopore- anus the secondary mouth
Protist common ancestor
animals share last common ancestor of a chaonoflaggellate protist from clade opisthokont
Chaonoflaggellate protists
unicellular heterotrophic sister group to animals
funnel shaped collar of microvilli
Evidence why protist is a common ancestor
collar cells in sponges
resemblance with animals not seen in fungi or plants
dna sequence homogeny
Neoproteozoic era
planktonic algae
neoproterozoic oxygenation event
presence of soft body multicellular organisms
sessile organisms
Neoproterozoic era cambrian explosion
rapid appearance of most animal phyla
some taxa (sponges) predated this event
hard body skeletons
Neoproterozoic oxygenation even led to increased body size increase O2
evolution of predation- increase in body complex body structures to help defend
evolution of how genes
Palaeozoic era
mesozoic era
Cenozoic era
p-animal diversity increased but then effected by end permian extinction, invertebrate moved to terra firmer
m- dinosaurs, mammals feathers, flight
c- diverse animals occupy different niches
Porifera (sponges) absence of tissue
absence of tissue- adult sponges lack nervous circulatory systems
use
Spicules- needles or rods made of silica or CaCO3
spongin- flexible fibrous collagen protein in some sponges
