BIS 2C: Sponges

Question 1

three lineages

Answer 1

glass sponges, demosponges, calcareous sponges

Question 2

symmetry and gut

Answer 2

asymmetrical gutless animals

Question 3

aquiferous system

Answer 3

branched water canals. water flow propelled by movement of flagella of many choanocytes

Question 4

cell types

Answer 4

differentiated cell types but no true tissues or organs

Question 5

cell arrangement

Answer 5

gelatinous matrix (mesophyll) with collage and usually spicules

Question 6

ostia

Answer 6

incurrent pores

Question 7

oscula

Answer 7

excurrent pores

Question 8

spicules

Answer 8

skeletal elements composed of silica or calcium carbonate

Question 9

siliceous spicules

Answer 9

glass sponges and demosponges

Question 10

calcium carbonate

Answer 10

calcareous sponges

Question 11

spongin

Answer 11

complex network of collagen

Question 12

sponge features

Answer 12

adults sessile, larvae motile

Question 13

what kind of feeders

Answer 13

filter feeders on microscopic particles

Question 14

reproduction

Answer 14

asexual: through “budding” or fragmentation
sexual: most sponges are hermaphrodites (monoecious) but not self fertilizing

Question 15

how do sponge sperm reach the egg?

Answer 15

cross the cellular barrier of choanocytes, enter the mesophyl, locate the egg and fertilize it

Question 16

life stages

Answer 16

fertilized egg (zygotę) to cleavage to blastula like stage

Question 17

Why are they dominant organisms?

Answer 17

• spicules provide physical deterrent
• potent biochemical defenses
• antimicrobial agents
• employ chemical warfare

Question 18

Symbiosis relationships

Answer 18

shrimp that is an obligate inhabitant of a glass sponge