Biology 11

Ms. Jamieson

Sponges (Porifera)

Read pages 560-563 and answer the following questions

Questions / Answers
What characteristics do sponges share with all other animals?
In what ways are sponges different from all other animals?
List the four types of cells in a sponge and describe their functions
The diagram at right represents the wall of a sponge with the different types of cells. Label the diagram
What are three functions of water flowing through a sponge?
What makes up a sponge skeleton?
Where does digestion take place in a sponge?
Most sponges are hermaphrodites. What does this word mean? (see the Glossary)
Describe how sponges reproduce sexually
The diagram at right represents fertilization occurring inside the wall of a sponge. Label the diagram
What are two methods of asexual reproduction used by sponges?
At right is a diagram of a gemmule. Label the diagram
Some sponges have a mutualistic relationship with photosynthetic microorganisms. What are the benefits for the sponge and for the microorganism?
How do sponges defend themselves?
How are the defensive compounds of sponges useful to people? / Multicellular
Heterotrophic
No cell walls
Specialized cell types
No mouth or gut
No specialized tissues or organ systems
Epidermal cells – the outside layer of a sponge
Pore cells – line the pores in the walls
Collar cells – flagella create current of water through the sponge
Amebocytes – build spicules

Delivers food and oxygen to the cells
Carries away carbon dioxide and other cellular waste products
Transports gametes or larvae out of sponge body
Spicules of calcium carbonate or silica
Protein called sponging
Inside cells, either collar cells or amebocyte
An individual that has both male and female reproductive organs
Sperm are released into the water and taken up by another sponge. They get caught by a collar cell and passed to amebocytes which carry the sperm to eggs in the body wall, where fertilization occurs. The zygote developes into a larva in the wall of the sponge and is then released through the osculum. It swims away and then settles down and grows into a new sponge.






Gemmules
budding


Microorganisms provide food and oxygen and remove wastes
Sponges provide shelter and carbon dioxide
They produce toxic compounds
Many are antibiotics, antiviral, useful against leukemia and herpes and arthritis