SERIES MICROBIOLOGY LAB PRACTICAL 1 (TAMUCC) COMPLETE QUESTIONS AND CORRECT ANSWERS | GRADED AND THE LATEST SERIES

Ans: Multiply the ocular lens (10x) by the objective lens 10x*10=100x 40x*10=400x 100x*10=1000x OCULAR TIME OBJECTIVE Question: what is the function of immersion oil when using the oil immersion objective? Ans: the immersion oil allows for magnification and increases the contrast of the specimen Question: What is meant by the term parfocal? Ans: Once the lens is focused on a particular area it will remain focused on the particular area regardless of changing the objective Question: why aren't the magnifications of both lenses of binocular microscope used to calculate total magnification? Ans: Because the image only goes through one ocular to reach both eyes SERIES Question: Why is the 10x placed in position when the microscope is stored or carried? Ans: The low-power objective is farther away from the stage than the other objectives so the lens is less likely to get scrapped during handling. Question: What is an aseptic technique? What is its importance? Why do you always have to do it in the microbiology lab? Ans: -Microbiologists use aseptic technique for a variety of procedures such as transferring cultures, inoculating media, isolation of pure cultures, and for performing microbiological tests. -Proper aseptic technique prevents contamination of cultures from foreign bacteria inherent in the environment. Question: what are some aseptic techniques used when transfering cultures from plate to broth tube and agar slant? Ans: 1. Prepare your desktop by swabbing down its surface with a disinfectant. 2. Wash your hands 3. With a marking pen, label a tube of sterile nutrient broth with name, date and specimen 4. Sterilize the inoculating loop by holding it over the flame of a Bunsen burner until it becomes bright red. The entire wire must be heated. Question: what is a culture medium? Ans: An artificial environment that provides water and nutrients for the microorganism Question: Types of culture media used in the lab based on form SERIES Ans: NA (Agar) Slant: solid at 50C or above, if below liquid NB tubes: liquid, cloudy, yellow NA Agar Plate: solid cloudy yellow Question: What is pure culture? Ans: population of cells derived from a single cell Question: What is a mixed culture? Ans: microbial culture consisting of two or more species Question: How do you sterilize an inoculating needle or loop? Ans: by putting it in the flame until the needle turns orange to know that it has been sterilized Question: Explain why petri dishes labeled on the edge of the bottom place and not on the lid