biology192 lecture 1

animal body plans

what distinguishes spiralian protostomes from ecdoysozoan protosomes

spiral cleave of embryonic cells

how do ecdysozoans grow

molting

cnidarians

anemones, corals, and jellyfish

requirements to be an animal

support their bodies

obtain energy

reproduce

five key innovations in the body plan

symmetry

tissues

body cavity

development patterns

segmentation

radial symmetry

any cut through the central axis produces two equal halves

do sponges have symmetry

no

bilateral symmetry

right and left halves along midline

radially symmetric animals’ characterisitcs

limited movement

sensory capabilities

bilaterally symmetric animals’ characterisitcs

greater potential for evolution of directed movement

associated sensory structures

tissues

collections of similar cells that carry out a specific function. differentiation is permanent

do sponges have tissues

no they are cell aggregates with cell specialization. individual cells can differentiate and redifferentiate

do all animals have tissues

yes, except for sponges

what type of tissues do radial animals have. do they have organs?

diploblastic - endoderm + ectoderm.

no organs

what type of tissues do bilateral animals have. do they have organs?

triploblastic - endoderm, ectoderm, + mesoderm

organs

what type of body cavity do animals have

a body cavity isolated from the exterior of the animal