Phylum Echinodermata

Question 1

Echinoderms exhibit this type of symmetry

Answer 1

The adult form of Echinoderms exhibit pentaradial symmetry but the larval form demonstrates bilateral symmetry.

Question 2

When asked on an exam what type of symmetry is shown in an
Echinoderm, which do you go with?

Answer 2

Bilateral symmetry

Question 3

Ossicles are the composition of the this phylums skeleton, what are the ossicles made of?

Answer 3

Calcium carbonate (CaCo3)

Question 4

What is the name of Echinoderms skeleton?

Answer 4

Ossicles

Question 5

The skeleton of which animal is called a “test?”
Name their class as well.

Answer 5

Sea urchins - Cl. Echinoidea

Question 6

In the order of most rigid to most flexible, where do the different classes of Echinoids fall?
(You can list them by their common name but try using only their class name if you can…and you CAN)!

Answer 6

1) Cl. Echinoidea - Sea urchins
2) Cl. Asteroidea -Sea stars
3) Cl. Ophiuroidea - Brittle Stars
4) Cl. Holothoroidea - Sea Cucumbers

Question 7

What structure is responsible for structural integrity of the animal?
(What makes it strong)?

Answer 7

The limbs and specifically the odd number of them.

Question 8

This feature is specific and cardinal to this phylum - what is it and what does it do?

Answer 8

Water Vascular System - is a system of canals and pipes.
Overall, the W.V.S. aids in locomotion, feeding, and the removal of waste.

Question 9

Name the structures that take part in the water vascular system

Answer 9

Ampulla
Tube feet
Madreporite

Question 10

Purpose of the ampulla?

Answer 10

Can act as a skeleton but it primarily a fixed volume of incompressible water.

Question 11

Purpose of the tube feet?

Answer 11

The tube feet are responsible for next to everything. They function in:
- attachment
- locomotion
- feeding
- gas exchange
- excretion

Question 12

Purpose of the madreporite?

Answer 12

“Mother button” is the pressure release valve.