ch 27 Animal Diversity Practice Quiz

There have been several major "forks in the road" of animal evolution. Place these events in chronological order. -evolution of specialized cell types, multicellularity, and sexual reproduction -evolution of true tissues from germ layers (and radial symmetry) -evolution of the embryonic mesoderm (and bilateral symmetry) -evolution of a true body cavity (coelom) -evolutionary divergence between protostome and deuterostome development

-1 -2 -3 -4 -5

Match each animal to the most appropriate description. [This animal] has _____ symmetry and _____ embryonic germ layers and _____ body cavity.

-Sponge no/zero/no -A cnidarian radial/two/no -A flatworm (platyhelminth) bilateral/three/no -A roundworm (nematode) bilateral/three/false (pseudocoelum -A segmented worm (annelid) bilateral/three/a true (coelum)

Match each animal to the most appropriate adaptation. -choanocytes for moving water with food particles -nematocysts for predation (and defense) -a radula for scraping food, a true coelom, and a spiral shell -two water siphons, a true coelom, and a two part shell with a hinge -tentacles, a beak, a true coelom, and excellent eyesight

-sponges -jellies, anemonies, and coral -gastropod mollusks -bivalve mollusks -cephalopod mollusks

Animals with bilateral symmetry tend to have a posterior "tail end" and an anterior "head" end with a mouth, a high concentration of sensory organs, and a neural processing center. The evolutionary trend toward having a head is called

cephalization

Placozoans, ctenophores, and cnidarians are all considered _______, since they have inner and outer embryonic cell layers.

diploblastic

Hox genes are associated with body segmentation, and segmentation is important in animal evolution because it

has allowed organisms to alter their body forms in complex ways.