Invertebrate Lecture Worksheet
All Materials Cmassengale


1. Approximately what percentage of animals are invertebrates?

 2. What are invertebrates?


3. Name the phyla of invertebrates and members of each phyla.




 4. __________ are in the phylum Porifera.  There are about _____ different species & most of  these are _________ organisms found in oceans & seas.  A few sponges are found in  __________, but these are small and not brightly colored.

 5. Sponges are _____________ that trap __________ from water as it flows through them.

 6. Sponges have no basic body arrangement and are said to be ________________.

 7. Sponges live attached to one spot as adults so they are __________.

 8. The skeleton of sponges is made of a flexible protein called ___________ and hard fibers  called __________ which are composed of calcium carbonate or silicon dioxide. 

9. Sponges are full of holes called __________ through which water flows into their __________  bodies. 

10. Sponges are the simplest animals and lack the __________ level of specialization like all other animals. Sponges do have some specialized _________ in their bodies.

11. Special cells called choanocytes line the pores and have __________ that spin to pull in water.

 12. __________cells at the base of choanocytes capture plankton from the water & start digesting it.

 13. _______________ are special cells that carry this food to all other parts of the sponge.

 14. Wastes and excess water leave a sponge through a large opening at the top called the   __________.

15. Sponges reproduce asexually by internal or external __________ and by _______________ whenever a piece of a sponge breaks off.  This last method helps sponges form   _____________.

16. Sponges reproduce sexually also and are _______________ producing both eggs and sperm.  Sponges __________ sperm with each other and do not fertilize their own eggs.

 17. Internal buds or ____________ form if the freshwater supply evaporates and are release  when the sponge __________ and become ___________ when freshwater returns.


 17. The phylum Cnidaria includes what organisms?


 18. All cnidarians are _______________ organisms except for the __________ which is found in freshwater.

19. Cnidarians all have _______________ symmetry and _____________ or arms that have stinging cells called _______________.  These stinging cells shoot out like a   _______________ and contain a __________ that can kill or paralyze their prey.

 20. Cnidarians have _____ body layers; an inner _______________ and an outer ____________.

 21. Cnidarians have _______ opening into their hollow bodies called the __________ so food enters and wastes leave through this same opening.  This is called a ________________ digestive system.

22. The hollow cavity the mouth opens into is called the ____________________ cavity.

23. Cnidarians have 2 body forms. ___________ forms have the mouth & tentacles located at the  top like Hydra, corals, and sea anemones. _____________forms like the jellyfish have their  tentacles and mouth located at the bottom.

 24. Some cnidarians like the _______________ go through both polyp and medusa forms in their life cycle. 

25. Cnidarians have a simple nerve _________ and can reproduce both _____________ and  _____________.

 26. Corals build _____________ cases that make underwater ___________.


 27. Flatworms are in the phylum _______________ and are flattened ______________ with  __________ symmetry.

28. Flatworms are said to be _________________ because of their solid body.

29. ___________and ____________ are parasitic flatworms having only _______ body opening called the _____________.

 30. Specialized _____________ cells remove wastes.

 31. The ______________ is the most common free living flatworm.  It is found in __________ or _____________ places.

32. Planarians produce both eggs and sperm and are said to be ________________; however, they _____________ sperm with other planarians.  Planarians also reproduce asexually by  _________________.

33. Flukes and tapeworms usually live in their host's ______________ tract resistant to digestive  _______________ allowing the __________ to digest their food.

34. Tapeworms are divided into sections called _________________ with complete  _________________ structures.  The head is called the _______________ and has both  _________________ and ______________ to attach to the host.   

35. Tapeworms are ___________________ and ______________ their own eggs which pass out of the host's body in ripe ____________________ along with feces. 

36. Humans get tapeworms from eating _______________________, while children pick up tapeworm eggs from ________________ boxes.


 37. _______________ are in the phylum Nematoda and are _________________ in shape and  ________________ at both ends.

38. Roundworms are ____________________ because their body cavity or       ________________is not fully lined. The body cavity is filled with fluid giving them a   ____________________ skeleton against which _______________can contract.

 39. Roundworms have a complete gut with both a ______________ and an _____________  giving them a ________________ digestive tract.

 40. Roundworms have no ____________ and no ___________ but can digest food.

 41. Most roundworms are _________________ with ________________ symmetry and no   _____________________.  They are found in _______________________.

 42. A protective __________________covers them and must be _____________.

 43. Roundworms reproduce _________________. 

44. The roundworm called Trichinella causes the disease _______________ and is picked up when someone eats ________________________.  This disease affects the ______________ and _______________.

 45. The roundworm Ascaris parasitizes human _____________________.   __________________  and _________________ are common parasites of humans, and the Filaria worm attacks the _________________ system causing great swelling.


 46. Rotifers are ___________________ worms found in terrestrial & aquatic habitats.

47. Rotifers have a crown of ______________ surrounding their mouth for ________________ and ______________________.  Their bodies are covered with ________________.

 48. Rotifers have separate _____________, but some species reproduce by       _______________________. 

49. Describe parthenogenesis.



50. Name several organisms in the phylum Mollusca.


51.Mollusks have a durable shell made of ________________ and are found      ________________.

 52. List several economic importance's of this group.



 53. Name the 2 largest invertebrates.


54. Mollusks have ________________ symmetry and a ___________________ containing their body organs.  Mollusks also have a muscular ____________ for movement which can be modified into arms or _________________.