Lab 9: Phylum Echinodermata

Question 1

Are Echinodermata protostomes or deuterostomes

Answer 1

Deuterostomes

Question 2

Do echinoderms belong to the sea, land, and freshwater?

Answer 2

No; there are no freshwater or terrestrial deuterostomes. They only belong to the sea

Question 3

What are Crinoidea? Which direction does their mouth face? What are its appendages?

Answer 3

Sea lillies and feather stars; mouth faces upwards; long branched arms that bear tube feet

Question 4

What are Holothuroidea?

Answer 4

Sea cucumbers

Question 5

What are Echinoidea? What are its appendages?

Answer 5

Sea urchins and sand dollars; body is globular or disk-shaped; skeletal plates fused into a rigid skeleton called a test

Question 6

What is a “test”?

Answer 6

In Echinoidea, the rigid skeleton that skeletal plates are fused into

Question 7

What are Ophiuroidea?

Answer 7

Brittle stars and basket stars

Question 8

What are Asteroidea? What are its appendages?

Answer 8

Sea stars; body star-shaped with 5 or more arms; thick arms not distinct from central body disk; tube feet lie in open grooves

Question 9

The larvae of echinoderms still retain what kind of symmetry?

Answer 9

Bilateral

Question 10

What are the four traits believed to make echinoderms successful that cnidarian do not have?

Answer 10

-Radial symmetry
-Triploblasty
-A coelom
-Endoskeleton

Question 11

What is pentaradial symmetry?

Answer 11

radial symmetry found in echinoderms; involves five parts arranged concentrically around a central axis

Question 12

Describe the Water Vascular System (WVS)?

Answer 12

system of fluid-filled canals unique to echinoderms; derived from the coelom; plays role in movement, gas exchange, circulation, and feeding

Question 13

What are the Ampulla and Podium?

Answer 13

The tube foot

Question 14

What are ossicles?

Answer 14

Calcium carbonate plates the endoskeleton of echinoderms is composed of

Question 15

What is structural support in echinoderms provided by?

Answer 15

An endoskeleton

Question 16

What is it called when the endoskeleton extends past the epidermis of some echinoderms?

Answer 16

Spines

Question 17

What are pedicellaria?

Answer 17

claw-like structure that sea urchins and sea stars have on their surface to keep the surface clean, protect from predators and capture prey.

Question 18

What is a unique function of ossicles?

Answer 18

Ossicles are bound together by connective tissue that allows them, through neurological control, can alter degree of stiffness and fluidity.

Question 19

What is the feeding strategy of echinodermata?

Answer 19

Feeders, scavengers, grazers, and carnivores.

Question 20

What kind of digestive tract do echinodermata have?

Answer 20

Complete

Question 21

What is gas exchange like in echinodermata?

Answer 21

exchange of gases occurs across skin gills, which are an en extension of the coelom, and pushed out to the surface between spines

Question 22

Where does gas exchange occur in echinodermata?

Answer 22

O2 moves from water into the coelom fluid of the skin gill; CO2 moves from in opposite directions. Gas exchange occurs across the surface of the fluid-filled tube feet.

Question 23

Digested nutrients from the digestive tract are circulated along with O2 around the body by the _____?

Answer 23

Coelom

Question 24

How do echinodermata excrete waste?

Answer 24

They have no excretory organs; nitrogenous waste diffuses across the skin gills from the coelomic fluid and across the tube feet

Question 25

How do echinoderms reproduce?

Answer 25

Sexes are separate and fertilization is external

Question 26

What kind of NS do echinoderms have?

Answer 26

Non-centralized; they have no brain. But they do have some sensorary cells that detect some dissolved chemicals, water current, light, position relative to gravity, and touch

Question 27

Each arm of a sea star has _______________ at its end that responds to _______ and ______ in the water

Answer 27

sensory tentacles; chemicals and vibrations

Question 28

Why does a sea star lift the end of an arm?

Answer 28

To percieve light and movement

Question 29

Which of the animals listed has a nervous system most like the nervous system of the sea star?

Answer 29

sea anemone

Question 30

What part of the body does a sea star use for locomotion?

Answer 30

Tube feet

Question 31

Do the tube feet of a sea star have suckers?

Answer 31

Yes

Question 32

What part of the brittle star’s body is primarily used for locomotion?

Answer 32

Arms

Question 33

Do the tube feet of a brittle star have suckers?

Answer 33

No

Question 34

Which of these has arms that are broadly attached the central disc?

Answer 34

Sea star

Question 35

Which type of echinoderm shows bilateral features, resembling an elongated cylinder with the mouth and the anus located at the opposite ends and dorsal and ventral sides?

Answer 35

Sea cucumber

Question 36

A sea cucumber that is a deposit feeder, moves along the sand on its ventral side and scoops sand into the moth at the anterior end. What comparison would you expect to see in the tube feet on the ventral and dorsal sides of this type of sea cucumber?

Answer 36

Expect the ventral tube feet to be larger and more developed than the dorsal tube feet.