Chapter 22

All animals ______. a. are motile for at least some stage in the life cycle b. consist of tissues arranged as organs c. can reproduce asexually as well as sexually d. both a and b

A coelom is a ______ a. lined body cavity b. resting stage c. sensory organ d. type of bristle

The cnidarians alone have _______ a. nematocysts b. tissues c. a hydrostatic skeleton d. radial symmetry

Flukes are most closely related to _______. a. planarians b. roundworms c. arthropods d. echinoderms

Which group has the greatest number of species? a. crustaceans b. insects c. mollusks d. roundworms

The nephridia of earthworms perform a function most similar to the ________. a. gemmules of sponges b. chelicerae of spiders c. flame cells of planarians d. tube feet of echinoderms

The ________ are coelomate and radial as adults. a. cnidarians b. echinoderms c. roundworms d. both a and c

Match the organisms with their appropriate descriptions _______ Ediacarans ______ sponges _______ cnidarians ______ flatworms ______ roundworms ______ annelids _______ arthropods _______ mollusks ______ echinoderms a. complete gut, false coelom b. simplest organ systems c. no tissues, no organs d.jointed exoskeleton e. mantle over body mass f. segmented worms g. tube feet, spiny skin h. nematocyst producers i. known from fossils only