Choose the best answer

1			Of the mollusks, snails are in the class of Need a Hint?
			A)	gastropods.
			B)	bivalves.
			C)	cephalopods.
			D)	chitons.
2			A mantle is Need a Hint?
			A)	present only in bivalves.
			B)	a structure that acts as a lung or contains gills.
			C)	a rasping, tonguelike organ in mollusks.
			D)	necessary for mollusks to be motile.
3			Segmentation was first apparent in the Need a Hint?
			A)	flatworms.
			B)	annelids.
			C)	mollusks.
			D)	arthropods.
4			Which of the following is not present in polychaetes? Need a Hint?
			A)	a coelom
			B)	parapodia
			C)	permanent gonads
			D)	setae
5			The lophophore, the structure characteristic of lophophorates, Need a Hint?
			A)	functions in gas exchange.
			B)	functions in feeding.
			C)	can be withdrawn when the animal is disturbed.
			D)	All of these are correct.
6			The phylum that shows the greatest diversity, or the greatest number of species, is Need a Hint?
			A)	Arthropoda.
			B)	Brachiopoda.
			C)	Echinodermata.
			D)	Mollusca.
7			Air for respiration enters the insect body through the Need a Hint?
			A)	tracheae.
			B)	spiracles.
			C)	tracheoles.
			D)	Malpighian tubules.
8			Arthropods shed their old exoskeleton as they grow in a process known as Need a Hint?
			A)	tagmatization.
			B)	metamorphosis.
			C)	chrysalis.
			D)	ecdysis.
9			Which animal group has radial symmetry, a water-vascular system, moves with tube feet, and has an endoskeleton? Need a Hint?
			A)	arachnids
			B)	crustaceans
			C)	echinoderms
			D)	cnidarians
10			The echinoderms that lack distinct arms are the Need a Hint?
			A)	brittle stars.
			B)	sea urchins.
			C)	sea stars.
			D)	Asteroidea.