Protozoans, Fungi, and Animal Parasites

Objectives

• Identify microscopic characteristics of organisms belonging to the kingdom protozoa.
• Identify macroscopic and microscopic characteristics of organisms belonging to the kingdom fungi.
• Identify macroscopic and microscopic characteristics of organisms belonging to the kingdom animalia, particularly helminths and arthropods.
• Compare and contrast methods for controlling health risks and treating each of these types of infections.
• Describe the important role of biomagnification and evaluate its impact on disease.

In an attempt to understand the diversity of life, biologists have placed organisms into groups. This is similar to the way that chemists have created the periodic table, where each column represents elements that behave in a similar manner. However, the number of organisms is unimaginable. We are still discovering new species every year. In fact, approximately 3 to 5 new bird species and many new mammal species are found every year. We have also found that some organisms that look very similar externally do not have similar ancestors, and are physiologically very different. Scientists feel that the closest relations between organisms are represented by the ability of the organism to mate with another. We refer to organisms related this closely as the same species.

The purpose of this lab is to compare and contrast characteristics of organisms in the domain eucarya, which will include protozoans, fungi, and some arthropods and helminths in the animal kingdom. An important thing to observe is the size of the individual cells and their relationships to one another. Much of the classification of these organisms is based upon their nutritional style and easily observable characteristics. The largest and most encompassing grouping of organisms is called a kingdom. These groups have broad similarities, although there are debates as to how many kingdoms there should be, we will use the most widely accepted classification—a 5-kingdom classification, including:

• Monera—Bacteria, surviving either as photosynthetic, chemosynthetic, or decomposing organisms. Relatively simple, single-celled prokaryotic organisms.
• Protista—Very diverse eukaryotic organisms, usually single-celled. Includes photosynthetic organisms, heterotrophs, and parasites. Classified by pigment or movement.
• Fungi—Multicellular eukaryotes. Heterotrophic, representing mainly decomposers— some pathogens and parasites. Classified by reproductive methods.
• Plantae—Diverse multicellular eukaryotes. Photoautotrophs. Classified by tissue structure and reproductive methods.
• Animalia—Animals. Diverse eukaryotic organisms. Heterotrophic, including predators and parasites.