Echinoderms - Starfish

Question 1

Symmetry, blastia and coelom

Answer 1

Adults show radial symmetry (penatmery) while larvae show bilateral symmetry, Triploblastic and coelomates

Question 2

What is the madreporite in Echinoderms

Answer 2

Opening to water vascular system found on the aboral surface

Question 3

What does the central disk contain in Echinoderms

Answer 3

Contains nerve rings and radiating nerve cords

Question 4

What is the role of the digestive glands in Echinoderms

Answer 4

Secrete digestive juices

Question 5

What is the surface covered in in Echinoderms and what is their role

Answer 5

Covered in spines for defence and gills for gas exchange

Question 6

How does the water vascular system work in Echinoderms

Answer 6

Water flows in from madreporite down into ring canal then 5 radial canal into podia
The valve at entrance of podia closes, ampulla at the top contract forcing water into the tube feet causing straightening and extension
The foot contacts a solid surface and muscles contract forcing water back up into the ampulla

Question 7

What are the 2 components of tube feet in echinoderms

Answer 7

The bulb-like ampulla and the suckered podium

Question 8

Give 1 example of class Asteroidea

Answer 8

Starfish

Question 9

Name given to the ability to regenerate limbs

Answer 9

Autotomy

Question 10

2 distinguishable characteristics of class Ophiuroidea

Answer 10

Distinct central disk with long flexible arms
Madreporite on oral side

Question 11

1 distinguishable characteristic of class Echinoidea

Answer 11

No arms

Question 12

1 distinguishable characteristic of class Holothuroidea

Answer 12

Oral-aboral axis greatly lengthened