Section 1
The Diversity of Animal Body Plans Arose by a Series of Evolutionary Innovations
Animals are unique in the fact that they possess _____ for movement and _____ for conducting signals between cells.a. brains; musclesb. muscle tissue; nervous tissuec. limbs; spinal cordsd. flagella; nerves
Animal cell walls are composed ofa. chitin.b. cellulose.c. peptidoglycans.d. silicon dioxide.e. None of the above; animal cells lack cell walls.
Body cavities differ from digestive cavities in thata. they are not connected to the outside.b. they are always surrounded by ectoderm.c. they are always filled with fluid.d. they are only found in asymmetrical organisms.