Microorganisms are the most common and the most numerous group of organisms on Earth. The world of Microbiology revolves around the ability to categorize and identify these microorganisms. The identification is especially important in the medical community to determine the cause of disease and effectively treat patients. Biology homework help
To identify unknown bacteria, Microbiologists use a diverse collection of tests including stains, biochemical tests, and selective and differential media. In general, the identification begins with a Gram stain and continues with a scientific identification process, sometimes dependent upon which ID is suspected. For example, if a child goes to the pediatrician with a sore throat, the doctor might look specifically for Streptococci in the child’s throat.
Given the massive number of bacterial species on Earth, you can imagine that all of this information can pile up. For decades, Microbiologists have relied upon collection of books known as Bergey’s Manual. This actually refers to a collection of books that provide detailed information on all recognized species of prokaryotes. Each chapter in Bergey’s Manual is written by an expert, contains tables, biochemical test results, and further systematic information that is useful for ID purposes.
Before completing this lab, take a look at the introduction in Bergey’s Manual.
(Typing in “page 1” in the upper right hand corner of the book will quickly get you to the introduction)
http://www.archive.org/stream/bergeysmanualofd1957amer#page/n21/mode/2up (Links to an external site.)
Write five paragraphs discussing the following five questions. Use in-text citations and references as appropriate. Submit the assignment one week from the date issued. Refer to your lab manual if need be.Biology homework help
1.) The Gram stain is typically the first test performed in a microbiology laboratory in the process of identifying an unknown. Why? Give two examples of instances when a Gram stain would NOT be a useful first step.
2.) What are biochemical tests and why are they performed?
3.) Give two examples of biochemical tests and identify why the tests are used.
4.) Imagine that you are working in a microbiology lab and you are given a sample of bacteria on an agar plate. You are told that it is either Staphylococcus aureus or Streptococcus pyogenes. How would you determine which one the sample contains? Are there any tests you could do to differentiate them?
5.) Why must these steps be followed? Wouldn’t it be easier to just observe the organisms under a microscope and make an identification based on observation?
6.) What is a dichotomous chart? How is it utilized?
7.) Give some reasons for using the following tests/observations: UV light exposure, zone of inhibition, citrate tests, ELISA test, Ames test, MacConkey agar, Nessler’s reagent Biology homework help