Module 1 Homework

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Module 01 Homework Assignment

Use the information presented in the module folder along with your readings from the textbook to answer the following questions. •Please try to write at least 2-3 COMPLETE sentences for your responses

1.Define and briefly describe the different classes of microorganisms (including the terms Eukaryotes and Prokaryotes):

1.Eukaryotes: Eukaryotes are living organisms whose cells are larger and more complex than prokaryotic cells and contain complex structures enclosed within membranes. Scientists believe that eukaryotes have evolved from prokaryotic symbiotic communities. If we use the rules of nomenclature and look at the binomial “eukaryote”, eu means good or with and karyon means nucleus; therefore, a simplified definition of eukaryotes is “with a nucleus”. a.Algae - Algae are a large and diverse group of simple organisms that can be unicellular or multicellular. These eukaryotic organisms have no roots, stems, or leaves but do have chlorophyll and other pigments for carrying out photosynthesis. Algae are found in aquatic bodies, both salt and freshwater, and in all types of soil. Scientists have yet to find significance for algae in the medical world. b.Fungi - Fungi (singular is fungus) are a very large and diverse group of eukaryotic, spore bearing organisms that include several thousand species. Yeasts, molds and mushrooms are all fungi, but are not microbes. Fungi obtain their energy by absorption of simple organic compounds found in soil and water. Although fungi play an important, major role in the breakdown of dead organic matter in the environments where they grow as well as being a food source, it is vital to remember that some fungi are pathogenic and can cause disease in animals and humans. c.Protozoans – Protozoans are single celled, free-living microorganisms that feed on other organisms for their energy source. Protozoans come in many different shapes and sizes, living in a wide variety of moist habitats including fresh water, marine environments and soils, yet all of them are colorless mobile organisms. Several protozoans are pathogenic to animals and humans.

2.Prokaryotes: Fossils of prokaryotes date back to 3.5 to 4 billion years; therefore, this rich fossil record or prokaryotic life alludes to the idea that prokaryotes were perhaps the first living things on the planet Earth. Prokaryotes are organisms that have a simple cell structure without a membrane bound nucleus or organelles. Scientists aptly named these ancient organisms using the rules of nomenclature as follows: pro, meaning before and karyon, meaning nucleus; therefore, prokaryote simply means, “before a nucleus.” a.Bacteria - Bacteria are a diverse group of prokaryotes that are present in soil and water, in animal digestive tracts and skin, as well as in many other environments and include some that are pathogenic. Different bacteria need different energy sources such as sunlight, organic chemicals, inorganic chemicals, or combinations of the above mentioned sources. b.Archaea - Archaea are a group of unicellular microorganisms that are similar to bacteria because they are also prokaryotes, but they are evolutionarily different. Archaea prefer to live in extreme environments such as glaciers, hot springs or highly salty environments that are also harder to get to; therefore, less information is known about Archaea than bacteria. Archaea are usually not involved in everyday human life. 3.Viruses - Viruses are submicroscopic particles, intracellular parasites that infect cells of other organisms, both prokaryotic and eukaryotic. Although viruses do carry genetic material in the form of either DNA or RNA, they are unable to replicate because they lack the biomechanical machinery necessary for reproduction. For a virus to reproduce it uses the biochemical machinery of its host cell. Viruses are classified as either RNA-containing or DNA-containing but can also be...
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