Question 1

How much nervous system does an echinoderm have? Sea stars have

Accepted Answer

A)  a complex of nerve ganglia in each ray.
B)  a central nervous system including a brain.
C)  a simple nerve ring and radial nerves leading to simple sensory cells scattered over the epidermis.
D)  no genuine nerve cells are found in echinoderms;they operate completely by a hydraulic system.

Question 2

Which of the following are considered "irregular" urchins?

Accepted Answer

A)  Sea urchins that swim
B)  Sand dollars and heart urchins
C)  Sea cucumbers
D)  Crinoids
E)  Brittle stars

Question 3

The most active of all echinoderms are the

Accepted Answer

A)  sea urchins.
B)  sea stars.
C)  sea cucumbers.
D)  brittle stars.
E)  crinoids.

Question 4

The ossicles are penetrated by a meshwork of spaces filled with fibers and dermal cells;the meshwork is _____________ and is unique to echinoderms.

Accepted Answer

A)  pyloric ceca
B)  radial canals
C)  polian vesicles
D)  coelomocytes
E)  stereom

Question 5

The fossil record of echinoderms

Accepted Answer

A)  is sparse with few representatives.
B)  shows echinoderms were a fairly modern group to arise.
C)  indicates early echinoderms were sessile and pentaradial but had a bilateral ancestor.
D)  suggests early echinoderms were free-swimming and bilateral but became sessile and pentaradial in recent times.
E)  is a clear and detailed history of complex echinoderm evolution.

Question 6

"Bipinnaria" describes the

Accepted Answer

A)  larval form of many echinoderms.
B)  central two-branched reproductive structures of sea stars.
C)  hydraulic system that controls the tube feet of sea urchins and sea stars.
D)  ability of these animals to grow into either males or females.
E)  underlying bilateral symmetry of an adult although it appears to be pentaradial.

Question 7

Within basic research,sea urchins have been a standard research animal in

Accepted Answer

A)  immunology.
B)  study of respiratory systems.
C)  study of bone.
D)  digestive anatomy.
E)  molecular embryology.

Question 8

During metamorphosis of sea stars,the left side of the larva becomes the oral surface of the adult,and the right side becomes the ___________ surface.

Accepted Answer

The answer of During metamorphosis of sea stars,the left side...

Question 9

The basic five arms of crinoids are usually branched to form many more,each of which bears barblike ___________.

Accepted Answer

The answer of The basic five arms of crinoids are...

Question 10

Pedicellariae are

Accepted Answer

A)  larval sea stars.
B)  the mouth-like openings into the center of the bottom of the sea star.
C)  structures linking the madreporite and the ring canal.
D)  small pincer-like projections clustered on the skin of a sea star which serve to keep it clean of parasites and aquatic growth.
E)  soft and delicate projections of the coelomic cavity covered with epidermis.

Question 11

________ ________ is a connective tissue that allows echinoderms to hold certain postures for long periods without straining muscles.

Accepted Answer

The answer of ________ ________ is a connective tissue that...

Question 12

The gill slits of enteropneust hemichordates function to

Accepted Answer

A)  house gills.
B)  strain food out of the water on the mucus-coated gill slits.
C)  allow water to exit after food has been gathered from the inflow.
D)  orient the animal in the water.
E)  excrete wastes.

Question 13

The oral tentacles of the sea cucumber are

Accepted Answer

A)  modified tube feet.
B)  actually primitive lophophores.
C)  elaborated pedicellariae.
D)  also part of its respiratory tree.
E)  completely new structures evolved in this group.

Question 14

The larva of an acorn worm is

Accepted Answer

A)  always a juvenile that grows into a bigger adult.
B)  a tornaria larvae that resembles an echinoderm bipinnaria larvae.
C)  very close in structure to a tunicate larva.
D)  nearly identical to a lancelet.
E)  None of the choices is correct.

Question 15

The respiratory tree of sea cucumbers opens into the _________________.

Accepted Answer

The answer of The respiratory tree of sea cucumbers opens...

Question 16

Arrow-worms feed

Accepted Answer

A)  on plankton and small fish.
B)  by retracting a hood and snapping onto food items.
C)  by surfacing at night and drifting transparently among plankton.
D)  All of the choices are correct.
E)  None of the choices is correct.

Question 17

Structures in each arm of a sea star include the gonads,the system that works the tube feet,and

Accepted Answer

A)  kidneys.
B)  hearts of a circulatory system.
C)  pyloric ceca that produce digestive fluids for extracellular digestion.
D)  the intestine that collects large amounts of wastes to expel through the anus.
E)  gills.

Question 18

________________ are pincer-like projections clustered on the skin of a sea star which serve to keep it clean of parasites and aquatic growth.

Accepted Answer

The answer of ________________ are pincer-like projections clustered on the...

Question 19

A feature of the earliest echinoderms apparently was development of endoskeletal plates with ______________ structure.

Accepted Answer

The answer of A feature of the earliest echinoderms apparently...

Question 20

Characteristics of the hemichordates that are shared with the echinoderms and are the basis for the clade Ambulacraria are a diffuse epidermal nervous system and _______ ________.

Accepted Answer

The answer of Characteristics of the hemichordates that are shared...

Exam 22: Chaetognaths, echinoderms, and Hemichordates

The basic five arms of crinoids are usually branched to form many more,each of which bears barblike ___________.

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________________ are pincer-like projections clustered on the skin of a sea star which serve to keep it clean of parasites and aquatic growth.

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Arrow-worms feed

Correct AnswerverifiedShow Answer

Within basic research,sea urchins have been a standard research animal in

Correct AnswerverifiedShow Answer

Characteristics of the hemichordates that are shared with the echinoderms and are the basis for the clade Ambulacraria are a diffuse epidermal nervous system and _______ ________.

Correct AnswerverifiedShow Answer

A feature of the earliest echinoderms apparently was development of endoskeletal plates with ______________ structure.

Correct AnswerverifiedShow Answer

The most active of all echinoderms are the

Correct AnswerverifiedShow Answer

Structures in each arm of a sea star include the gonads,the system that works the tube feet,and

Correct AnswerverifiedShow Answer

"Bipinnaria" describes the

Correct AnswerverifiedShow Answer

The larva of an acorn worm is

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Which of the following are considered "irregular" urchins?

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The respiratory tree of sea cucumbers opens into the _________________.

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The fossil record of echinoderms

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The ossicles are penetrated by a meshwork of spaces filled with fibers and dermal cells;the meshwork is _____________ and is unique to echinoderms.

Correct AnswerverifiedShow Answer

The oral tentacles of the sea cucumber are

Correct AnswerverifiedShow Answer

How much nervous system does an echinoderm have? Sea stars have

Correct AnswerverifiedShow Answer

________ ________ is a connective tissue that allows echinoderms to hold certain postures for long periods without straining muscles.

Correct AnswerverifiedShow Answer

The gill slits of enteropneust hemichordates function to

Correct AnswerverifiedShow Answer

During metamorphosis of sea stars,the left side of the larva becomes the oral surface of the adult,and the right side becomes the ___________ surface.

Correct AnswerverifiedShow Answer

Pedicellariae are

Correct AnswerverifiedShow Answer

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Characteristics of the hemichordates that are shared with the echinoderms and are the basis for the clade Ambulacraria are a diffuse epidermal nervous system and _ __.

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is a connective tissue that allows echinoderms to hold certain postures for long periods without straining muscles.

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