Animals

Animals

________: multicellular, eukaryotic heterotrophs that feed by ingestion & dont have cell walls.

Animals

multicellular, eukaryotic heterotrophs that feed by ingestion & dont have cell walls

have 2 unique cell types related to motility

muscle + nerve

Unique Traits of Animals

- no cell walls
- gametic life cycle
- all multicellular
- have collagen
- 2 unique cell types for motility: muscle & nerve

Collagen

protein in connective tissues

Animal Phylogeny

Porifera
Ctenophora
Cnidaria
Acoela
Deuterostomia
Lophotrochozoa
Ecdysozoa

PCCADLE = PAPYRUS CAN COOK AND DANCE, LOVES EVERYONE

Common ancestor of all animals evolved

770 MYA

Eumeterazoa

"true" animal, all but porifera

Name for all animals

metazoa

Bilaturia includes

Acoela
Deuterostomia
Lophotrochozoa
Ecdysozoa

Key Evolutionary Steps in Animals

1. true tissues (muscle and nerve tissue)
2. Bilateral body plan
3. notochord
4. lophophone or trochophone

porifera do not have

true tissues

Cnidaria do not have

A bilateral body plan

Only deuterostomia have

a notochord

Only lophotrochozoa have

lophophones & trochophones

3 lines of evidence that makes Choanoflagellates sister taxa to the animals

1. morphological similarities
EX: collar cells of sponges are almost identical to choanoflagellates
2. similar cells to collar cells have been found in animals but no other non animals
3. DNA sequence data