Animals & Animal Evolution

what subgroup of eukaryotes do we find “animals”?

opisthokonta, or opisthokonts

the term “opisthokonts” mean what?

rear flagellum

what are considered the "sister group” to animals?

choanoflagelates

metazoa

animals

what are the characteristics of animals (metazoans)?

1. cell structure

2. nutrition

3. movement

4. reproduction & development

explain the cell structure of animals

multicellular, flexible, extracellular matrix

explain the nutrition of animals

heterotroph (can’t make their own food), internal digestion

explain the movement of animals

muscle tissue, locomotion (movement of own accord), nervous system

explain the reproduction & development of animals

most animals reproduce sexually, embryonic development

what are the major features that differentiate metazoan groups?

1. body plan symmetry

2. germ layers

3. embryonic development

explain germ layers

the layers you have in the early stages of embryonic development

• diploblast

• triploblast (us—bilaterians are the only ones with a mesoderm)

endoderm

digestive system; inner layer of diplo/triploblast

non-living layer

layer in a diploblast b/w endo&ectoderm

ectoderm

skin, appendages; outer layer of diplo/triploblast

mesoderm

layer in triploblast (more specifically, bilaterians) that contains other organs