Porifera

Question 1

Habitat and Lifestyle

Answer 1

Marine and freshwater
Sessile as adults – motile larval stage
Suspension feeders (one exception)

Question 2

Characteristics (3)

Answer 2

An interconnected system of water canals – no gut
Choanocytes – distinctive cell type
No nerve/muscle tissue, protoepithelia and connective tissue

Question 3

Choanocyte Roles (4)

Answer 3

Create water current through the sponge (bring in food, bring in oxygen, expel waste products, disperse gametes)
Food capture (phagocytosis)
Sperm Capture
Differentiate into sperm

Question 4

Archaeocytes Roles (5)

Answer 4

Food digestion
Storage of nutrients 
Differentiate into gametes
Secrete skeletal elements (calcareous spicules, siliceous spicules, spongin)
Totipotent (ability to differentiate)

Question 5

Grades of structural complexity (3)

Answer 5

Asconoid: simple single atrium
Syconoid: Infolding radial canals
Leuconoid: Complex internal flagellated chambers (mult. oscula)

Question 6

Class Calcarea

Answer 6

Calcareous spicules

all 3 structural types

Question 7

Class Demospongiae

Answer 7

Siliceous spicules and/or spongin
Leuconoid structure
Most sponges belong to this class

Question 8

Class Hexactinellida

Answer 8

Siliceous spicules (6 points) may be fused
Syncytial tissue

Question 9

Reproduction and Development (6)

Answer 9

Most are hermaphroditic
Sperm and spawned
Sperm captured by choanocytes and delivered to eggs
Mostly internal fertilization with development in the mesohyl
Free-swimming sponge larva
Gemmules are an overwintering stage of freshwater sponge

Question 10

Basic Body Plan

Answer 10

No true tissues with an exterior pinacoderm middle mesohyl made of archaeocytes and interior choanocyte layer