Microbiology

Create a 2- to 3-page document in Microsoft Word for providing answers to questions in the following review sheets:Support your responses with examples.Cite any sources in APA format.Exercise 4: Pure bacterial colonies1.   When an agar plate is inoculated, why is the loop sterilized after the initial inoculum is put on?2.   Distinguish between a pure culture and a mixed culture.3.   Define a bacterial colony. List four characteristics by which bacterial colonies may be distinguished.4.Why should a Petri dish not be left open for any extended period?5.   Why does the streaking method you used to inoculate your plates result in isolated colonies?Exercise 5: Pour plate and streaking technique to obtain pure cultures1.   Discuss the relative convenience of pour- and streak-plate techniques in culturing clinical specimens.2.   How do you decide which colonies should be picked from a plate culture of a mixed flora?3.   Why is it necessary to make pure subcultures of organisms grown from clinical specimens?4.   What kinds of clinical specimens may yield a mixed flora in bacterial cultures?5.   When more than one colony type appears in pure culture, what are the most likely sources of extraneous contamination?Exercise 3: Primary media for isolation of microorganisms1. Define a differential medium and discuss its purpose.2. Define a selective medium and describe its uses.3. Why is MacConkey agar selective as well as differential?4. Why is blood agar useful as a primary isolation medium?5. What is the major difference between Modified Thayer-Martin (MTM) and chocolate agar? When would you use MTM rather than chocolate agar?