Intro to Animals
Card Set Information
Intro to Animals
What gives rise to tissues and organs?
the embryonic/germ layers
What is Diploblastic?
have 2 germ layers (ectoderm and endoderm)
includes cnidarians (jelly fish and anemone) and comb jellies
What is Triploblastic?
have 3 germ layers (ecto, endo and mesoderm)
: flatworms, arthropods (have an exoskleteton), vertebrates and others
What is a coelem?
a true body cavity (derived from mesoderm)
fluid or air filled space
internal organs are suspended in
What is a pseudocoelom?
body cavity derived from meso and endoderm
What are triploblastic animals with a body cavity called?
What are triplosblastic animals lacking a body cavity called?
What are the two main types of cell development?
Protostome and deuterostome
What is protostome development?
spiral (cells are not parallel)
have a determinate cleavage
fate of cell is determined early
What is deutrostome development?
Radial (form parallel/perpendicularly)
each cell can complete an embryo (can from identical twins)
What characteristics do the old and new tree agree on?
All animals share the common ancestor colonial flagellate
sponges are basal animals
Eutetazoa is a clade with true tissues
most animal phyla belong to the clade Bilateria
chordates belong to the clade Deuterostomia
What characteristics do the old and new tree disagree on?
old: divides bilaterian into the clades deuterostomes and protostomes
New uses three clades: deuterostomia, ecdysozoa and Lophotrochozoa
What are the old and new trees based on?
new= molecular evidence
What did the common ancestor of animals resemble?
Characteristics of Choanoflagellata
single flagellum surrounded by collar of microvilli
fingerlike projections of cell membrane
similar cell morphology to sponges
What appeared in the Cambrian period?
complex life, including those with skeletons appeared (most major phyla appeared)
during Paleozoic era (542-251 mya)
first mammals emerged
dinosaurs were dominant terrestrial vertebrates
coral reefs emerged
plants and insects became more diverse
began with mass extinction of animals
mammals became dominant