Phylum Echinodermata I

Question 1

Major Characteristics (5)

Answer 1

Ecoelomate deuterostomes

Water vascular system

Calcareous endoskeleton: mesodermal derivative, ossicles, microporosity

Pentamerous radial symmetry (pentaradial symmetry)

Mutable collagenous tissue

Question 2

Asteroidea

Answer 2

Sea stars and starfish
Latticework of interconnected ossicles (via collagen) for the endoskeleton
Pedicellariae on the aboral surface for protection

Question 3

Water vascular system 
And components (9)

Answer 3

Interconnected tubules of water used for locomotion

Madreporite, stone canal, ring canal, radial canal, lateral canal, ampulla, Polian vesicle, Tiedmans bodies

Question 4

Coelomic compartments (4)

Answer 4

Water vascular system
Perivisceral coelom
Perihemal coelom
Genital coelom

Question 5

Nervous system

Answer 5

The radial nerve is intraepithelial
This is the same as cnidarians
Neurites within the epidermal cells

Question 6

Feeding and Gut Structure

Answer 6

Use tube feet to pry open small gaps in the bivalve shell
Every cardiac stomach into prey to begin digestion
Food transferred to the pyloric stomach
The pyloric caecum is short term storage of food, for gamete production

Question 7

Asteroidea Asexual Reproduction

Answer 7

Fission via autotomy
A highly extensible state of collagenous tissue breaks off with part of the central disk
Regenerate the entirely new body from here

Question 8

Asteroidea Sexual Reproduction

Answer 8

Dioecious mostly
Broadcast spawn
External fertilization
Genital pores on the aboral surface
Larva swims in the water column and feeds
Uses nutrients to grow juvenile inside the larval stage
Catastrophic metamorphosis