Objectives

Through investigation, students should be able to
  1. Appreciate biological diversity amongst protists.
  2. Compare and contrast various sub-groups of protists, in terms of cellular structures, locomotory structures, and nutrition.
  3. Understand the life history, ecology, habitats, and protective adaptations of selected protists.
  4. Review the economic importance of the group Protista.

Introduction


Unlike bacteria which are prokaryotic, protists (Kingdom Protista) are eukaryotic, i.e., are characterized by membrane-bounded organelles. It is very complex and diverse in cellular structure, nutrition and many other characteristics. The concept of one kingdom for such a diverse group is being challenged, for a number of taxonomists are arguing in favor of splitting up the group into six or more kingdoms to reflect obvious evolutionary differences. Cell structural variations include unicellular, filamentous, colonial, and multicellular forms. Members include protozoa, algae, and slime molds. Each of these subgroups are further divided. For example, the heterotrophic protozoa are divided into pseudopods, flagellates, and ciliates based on their locomotion. Protozoa are either heterotrophs (through absorption, ingestion, or parasitism) or autotrophs (through phorosynthesis). Reproduction is usually asexual, but sexual reproduction is also common.


Pre-Activity

Answer the following prior to the start of this assignment (for homework):

1.Define the following terms:
  • Autotrophs
  • Photoautotrophs
  • Heterotrophs
  • Phagocytosis
  • Parasitism
  • Alternation of Generations
2. Complete the following chart as to the mode of nutrition of the following groups:
Group
Photoautotrophic (yes or no)
Heterotrophic (yes or no). State ingestion or parasitism if yes.
Example organism
chlorophyta



ciliophora



oomycota



myxomycota



phaeophyta



rhodophyta



3. Define the function of the following including an example:
  • pseudopods
  • cilia
  • flagella




Activity 1

For the following activities, we will view the Amoeba, Euglena, Paramecium, Spirostomum, Stentor, Volvox.


  1. Identify the taxonomic group (Phylum) that each of the above belong to.
  2. Identify 2-3 economic uses of the protista from those listed above. Please explain.
  3. View the protozoa above, using a wet mount slide. Complete the table as shown below. Take a picture with the moticam. Label with the structures discussed in the table (hint: research the protist to identify what you should be seeing.)

Protozoan
Cell shape
Structure/method of locomotion
Other cellular features seen
Unicellular or multicellular?
Interesting observations







Activity 2


Hydra, and Euglena (these organisms are not protists, but are interesting to observe and study)

1. State the phyla of hydra
2. State the phyla and class of euglena
3. View a wet slide(without cover slip-stay on low power) of hydra using a concave slide. Take your probe and gently touch the tentacles and base of the
hydra. Turn the light down on your microscope to check for the release of structures. Note the reaction of the organism. Take a picture using the
moticam. Label at least three structures.
4. View a wet slide of the euglena using the concave slide(stay on low power). Observe body movement internally and externally. Gently probe the
euglena to observe reaction to stimuli. Take a picture using moticam. Label at least three structures.
5. Place the hydra and the euglena on the same concave wet slide. Observe the reaction of both species. Is there a predator-prey relationship? Explain


Phyla/Class
Traits of Phyla/Class
Reaction to Stimuli
Predator/Prey Relationship
Interesting Obsevations
Hydra





Euglena





Amoeba video



Mrs Wolfgang's Student Teams


Mrs.Maine's student teams