Phylum Porifera




Дата канвертавання25.04.2016
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Phylum Porifera Name:
This phylum contains one of the oldest organisms, SPONGES, which date back to the Cambrian period. Sponges are in the phylum Porifera because they have pores all over their body. They were once thought to be plants because they are sessile but are now grouped as animals because they are MULTICELLULAR, HETEROTROPHS that contain SPECIALIZED CELLS with NO CELL WALL.
Sponges can reproduce sexually, keeping their eggs inside their body and releasing sperm into surrounding water. An amebocyte of another sponge collects the sperm and takes it to the egg. Once fertilized, the zygote develops into a larva that swims away to settle and grow elsewhere. Asexually, sponges bud or produce gemmules, which are amebocytes surrounded by spicules that grow into new sponges. This happens in unfavourable conditions.
Sponges interact with their environment despite their sessile nature. They have symbiotic relationships with non-animals such as blue-green algae, which provide it with oxygen. They also provide shelter for marine animals, are a food source for snails, starfish and fish, and they recycle old shells on the ocean floor.
Sponges produce chemicals that are toxic to many organisms to protect themselves. Humans now use these chemicals in antibiotics.
Form and Function
Sponges belong to the phylum Porifera and live in fresh or marine environments. They are so different from all other animals that they were once thought to be plants. They barely move, have no specialized tissues or organ systems and have nothing that resembles a mouth or a gut. Because sponges are sessile, they have to find a way to catch food without moving and fend off predators since it is basically a “sitting duck”. Sponges are filter feeders that sift microscopic particles of food from the water. The body of a sponge has pores (holes) all over it. It is designed so that water flows in through the pores to a central cavity and out. This allows for the movement of water to serve as the respiratory, excretory and internal transport system.

Phylum: Porifera



Common Name: Sponges
Habitat: Aquatic, both fresh water and marine
Key Characters:






Body Plan:










    1. Label the parts of the sponge and fill in the functions on the next page:



Sponge Diagram:

























Functions:




  1. The area enclosed by the body wall of the sponge __________________

  2. A special kind of cell that builds spicules __________________

  3. Cells that have flagella and trap food particles _________________

  4. One of thousands of openings in the body wall ________________

  5. The large hole from which water leaves the sponge ________________

  6. One of many structures that form the skeleton of the sponge ___________

  7. Specialized cells through which water enters the sponge ________________

  8. Cells on the outer surface of the sponge _______________





    1. Define sessile


    1. Describe a spicule (function and material). Draw a spicule from the prepared slide.











    1. Sponges ingest food by filter feeding. Explain what this means and how they accomplish it.






























    1. Sponges have no specialized organs for respiration and excretion. How do Sponges manage to respire and excrete wastes. Name the specific processes.









































    1. Briefly describe sexual reproduction in Sponges.
























    1. Define gemmule and explain its role in a Sponge’s life.
















    1. Describe at least 2 ecological roles of Sponges.










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