pic (2)

Distinguishing Characteristics:

• Animals are multicellular, heterotrophic eukaryotes with tissues that develop from embryonic layers (3)
• Heterotrophs that ingest their food (3)
• Have 3 types of tissue in animals (4):

1. Epithelial
2. Connective
3. Muscular

• Body Plans (3):

1. Symmetry-  ranges from none at all to radial or bilateral, bilaterally symmetrical animals have dorsal and ventral sides as well as anterior and posterior ends
2. Tissues- Eumetazoan (does not include sponges and other animals) embryos are diploblastic (2 germ layers) or triploblastic (3 germ layers)
3. Body Cavities- (triploblastic animals) may be present or absent, can be pseudocoelom (derived from both mesoderm and endoderm) or true coelom (derived only from mesoderm)
4. Protostome and Deuterostome Development- differ in patterns of cleavage, coelom formation, and fate of the blastopore

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pic (5)

Embryonic Development(4):

Protostomes:

• Determinate cell fate
• Spiral cleavage
• Mouth develops first
• ex) worms and bugs
• Schizocoely- coelom develops as mesoderm splits

Deuterostomes:

• Indeterminate cell fate
• Radial cleavage
• Mouth develops second
• ex) sea stars and humans
• Enterocoely- coelom develops as lateral extension of the gut

pic (6)