I. Phylum Porifera (pore bearing)

Question 1

Phylum Porifera (sponges) characteristics

Answer 1

Asymmetrical, some considered radial
No tissues (parazoa) or organs
Specialized cell types
Filter feeding
Sessile
Waste - diffusion of ammonia
Gas exchange - diffusion

Question 2

3 cell types

Answer 2

Pinacocytes - form outer layer of sponge
Amoebocytes - mobile cell, move around in a jellylike matrix (mesohyle) - functions; food storage and transport, skeleton formation, reproduction
Choanocytes - (collar cells) unique to phylum, flagellated cells that filter bacteria, algae, protists (food vacuole)

Question 3

Skeleton

Answer 3

Used for classification

Spicules, spongin, or both form the skeleton of the sponge, strengthening its body

Question 4

Spicules

Answer 4

Needle like spines, can be either calcium carbonate or silica

Question 5

Spongin

Answer 5

Tough protein fiber (collagen)

Question 6

3 body types (forms)

Answer 6

Ascon - most simple body form, spongocoel is lined with choanocytes, has a single osculum (small)
Sycon - folding of the ascon body plan, radial canals that are lined with choanocytes, has 1 spongocoel & osculum
Leucon – most complex, most common, chambers lined with choanocytes, increased filtering = increased size

Question 7

Classes of sponges

Answer 7

Calcarea
Hexactinellida
Demospongiae

Question 8

Class Calcarea

Answer 8

Calcium carbonate spicules
All 3 body types
All marine

Question 9

Class Hexactinellida (glass sponges)

Answer 9

Silica spicules, six spined (hex)

Sycon or leucon body types

Question 10

Class Demospongiae (bath sponges)

Answer 10

Silica spicules, spongin or both
Leucon body types
1 fresh water family