Animal Diversity Flashcards
sponges
most basal
phylum: porifera
animals =
multicellular
heterotrophic
eukaryotes
w/ tissues that develop from embryonic layers
tissues
groups of similar cells working together
most animals digest food how?
internally
(plants produce their own)
(fungi digest externally)
most reproduce how?
sexually
cell cleavage
cell division without growth
leads to ball of cells - bastula
animal share what genes?
hox genes
Metazoa, eumetazoa, bilaterians
all animals, all but sponges, everything other than cnetophora cnideria and porifera
tissues characterize
eumetozoa
Organization of tissues
diploblastic
triploblastic
diploblastic
two germ layers
ectoderm - outer covering and central nervous system
endoderm - innermost layer, lines digestive tract and pouch of gut
triploblastic
three germ layers
ectoderm
endoderm
mesoderm - fills space between ectoderm and endoderm; gives rise to muscles and most organs
Body Cavity functions:
cushion suspended organs
fluid in body cavities can act like a skeleton
internal organs can grow and move independently of the outer body wall
Body Cavity Types:
Coelom - develop w/in mesoderm
hemocoel - develop between mesoderm and endoderm
contains hemolymph for nutrient transport
no body cavity
symmetry
radial - just a central axis
bilateral - mirror images on just one axis (left and right)
- sensing organs at front end, centralization of nerves into a brain
what determines evolutionary relationships?
genomes,
morphological traits
rRNA
Hox genes
protein coding nuclear genes
mitochondrial genes
based on animal phylogeny
- animals share a common ancestor
- sponges are the sister group to all other animals
- eumetazoa = clade defined by tissues
- most animals belong to bilateria
- three major clades of animal bilateria
- most animals are invertebrates
Clades of Bilaterians
deuterostomia
lophotrochozoa
ecdysozoa
deuterostomia
includes: echinoderms, chordates, acorn worms
distinct bastula development, how cells divide, how coelem/mesoderm forms, how digestive tube forms
lophotrochozoa
platyhelminthes, mollusca, annelida
united by genetic characteristics
ecdysozoa
arthropods, nematodes
exoskeleton that can be shed via ecdysis
ecdysis
inflating and hardening that falls off
