Exam 16: Ambulacraria: Echinoderms and Hemichordates

Some sea cucumbers have special tubules of the respiratory tree that contains sticky secretions and toxins and can be everted through the anus; these are called __________ tubules.

Sea stars typically feed

Sea daisies were formerly assigned to a class of their own.They have been recently assigned to the echinoderm class

If a brittle star is grasped by an arm,certain muscles may contract to serve and cast off the arm in a process called

Regeneration of lost parts of a sea star also serves in

Which of the following is a characteristic of animals in the phylum Hemichordata?

Enteropneusta and Pterobranchia are classes of animals within the phylum Hemichordata.All of the following are features relating to reproduction in members of the Hemichordata.Three features listed are either common to members of both classes or occur only in Enteropneusta.Select the one feature that occurs only in Pterobranchia.

Echinoderms and hemichordates are more closely related to mammals than to crabs and shrimp.Indicate below if this statement is True or False,followed by the correct reasoning for that answer.Check all of the answer choices that apply.

The echinoderms that most closely resemble fossil forms are the

In sea stars,contraction of the __________ force water into the tube feet of the water vascular system.

The skeleton of sea urchins consists of ten sets of closely fitting plates and is called a(n)

Coiled masses of fecal material called __________ are deposited on the substrate at one of the openings of the burrow of an enteropneust.

Sea cucumbers belong to the echinoderm class

The characteristic larval stage of brittle stars is the

In the sea stars,a(n)__________ groove runs along the underside of each arm.

Synchronous spawning by enteropneusts suggests the presence of

The principal nitrogenous waste of sea stars is

Embryologically,the echinoderm water vascular system originates as modification of the

The water vascular system of echinoderms carries out many functions that are distributed through multiple systems in other animals.Which of the statements below are valid comparisons between the functions of the water vascular system and similar functions in arthropods? Check all that apply.

In Asteroidea the ________ system consists of strands of tissue that encircle the mouth near the ring canal and run into each arm near the radial canals.As in other echinoderms,this system probably transports digestive products,hormones,and other substances.