Animal Diversity Flashcards
Multicellular, heterotrophic eukaryotes with tissues that develop from embryonic layers
Animals
Nutritional mode of animals
heterotrophs
How do animals get nutrients?
Ingest their food
Animal cells have______
no cell walls
Structural protein that holds up animals bodies
collagen
unique to animals
(tissues)
Nervous and muscle tissue
How do most animals reproduce?
Sexually
Dominant life cycle of animals
Diploid stage
Rapid cell division of zygote that occurs after fertilization
cleavage
Forms as the result of cleavage
Blastula
Stage where gastrula forms
Gastrulation
Gastrula is made of different layers of
embryonic tissues
Sexually immature and morphologically distinct from the adult
Larva
Only animals possess this gene
Hox genes
Regulate the development of body form
Hox genes
Hox genes provide a wide diversity of
animal morphology
May have lived between 675-875 million years ago
common ancestor
common ancestor of living animals may. have resembled
choanoflagellates, protists
Marks earliest fossil appearance of many major groups of living animals
Cambrian Explosion
Possible hypotheses about cause of Cambrian explosion
new predator prey relationships, rise in atmospheric oxygen, evolution of Hox gene complex
Animals began making impact on land
Mesozoic Era
(Mesozoic era) emerged and became important marine ecological niches
coral reefs
These were dominant terrestrial vertebrates in Mesozoic era
dinosaurs
First mammals emerged
Mesozoic era
Beginning of this era followed mass extinctions of terrestrial and marine animals
Cenozoic era
These diversified during Cenozoic
Modern mammal orders and insects
Set of morphological and developmental traits used to categorize animals by zoologists
Body plan
Group whose members share key biological features
Grade
body parts arranged around central axis
radial symmetry
Two sided symmetry
Bilateral symmetry
The development of a head
Cephalization
Three germ layers that give rise to tissues and organs of animal embryo
endoderm, ectoderm, mesoderm
the germ layer covering the embryo’s surface
ectoderm
the innermost germ layer
endoderm
endoderm lies this developing digestive tube
archenteron
Have ectoderm and endoderm
Diploblastic animals
Have ectoderm, endoderm and mesoderm
Triploblastic
True body cavity
Coelom
Is derived from mesoderm
Coelom
Animals that possess a true coelom
coelomates
Body cavity derived from the mesoderm and endoderm
Pseudocoelom
Triploblastic animals that posess a pseudocoelom
Pseudocoelomates
Triploblastic animals that lack a body cavity
Acoelomates
Cleavage pattern in protostome development
spiral and determinate
Cleavage pattern in deuterostome development
Radial and indeterminate
Each cell in the early stages of cleavage retains the capacity to develop into a complete embryo
Indeterminate cleavage
Two phylogenetic hypotheses
genetic/molecular camp and morphological/developmental camp
All animals share a common
Ancestor
Clade of animals with true tissues
Eumetazoa
Most animal phyla belong to this clade
Bilateria
Two clades of bilaterians
deuterostomes and protostomes
Shed their exoskeletons by molting
Ecdysozoans
Ecdysis
molting
mouth develops before anus
Protostome
anus develops before mouth
Deuterostome