Lab 8. Phylum Porifera and Phylum Cnidaria

Question 1

mesohyl

Answer 1

extracellular gelatinous matrix

Question 2

spicules

Answer 2

Skeleton: spicules in a fibrous
network of spongin (collagen)

Question 3

osculum

Answer 3

excurrent opening
(larger)

Question 4

choanocytes (collar cells)

Answer 4

-Flagellated; create current flow
-flagellated “collar cell”
– Flagella beats; pulls water in through ostia
– ‘collar’ of microfibrils traps particles
– choanocytes phagocytize particles & pass them to achaeocytes for digestion
– Digestive system is intracellular

are cells that line the interior of asconoid, syconoid and leuconoid body types of sponges that contain a central flagellum, or cilium, surrounded by a collar of microvilli which are connected by a thin membrane.

Question 5

spongocoel

Answer 5

the large, central cavity of sponges. Water enters the spongocoel through hundreds of tiny pores (ostia) and exits through the larger opening (osculum).

Question 6

spongin

Answer 6

the horny or fibrous substance found in the skeleton of many sponges

Question 7

ostia (pores)

Answer 7

incurrent
opening (small pores)

Question 8

archaeocytes, collencytes

Answer 8

-ameboid cells; phagocytize particles esp. particles for digestion
– Differentiate into other types of cells
* sclerocytes – secrete spicules
* spongocytes secrete spongin
* Collencytes secrete collagen

Question 9

asconoid structure

Answer 9

simplest; choanocytes
line spongocoel

Question 10

syconoid structure

Answer 10

body wall folded;
choanocytes line radial canals

Question 11

leuconoid structure

Answer 11

most complex;
choanocytes line internal chambers

Question 12

pinacocytes, pinacoderm

Answer 12

outer layer (called Pinacoderm)
– Can ingest food particles (phagocytosis)
– Some contractile (myocytes); especially around ostia or oscula
– Not a true tissue (no basal lamina)

Question 13

polyp

Answer 13

sessle (dont move)