BIOD 171 (Biod171)

1. What type of bacteria does MacConkey agar select for? Gram-negative bacteria 2. Sorbitol MacConkey (SMAC) agar is: A. Selective media B. Differential media C. Selective and differential media D. None of the above C 3. What pathogen is best identified using a SMAC agar? E coli O157:H7. SMAC agar specifically differentiates between non-pathogenic E coli and the pathogenic E coli strain O157:H7. 4. What is the purpose of doing a 4-phase dilution streak? The purpose of a ...

Creating a hydrophobic barrier (the circle) helps to keep the water within the circle so it does not spill off of the slide. 4. What dye do Gram-positive bacteria primarily retain? Crystal violet 1. Why are Gram-positive bacteria able to retain the crystal violet dye? They contain a thick peptidoglycan layer in their cell wall that readily retains the dye. 2. Identify the Gram status (positive or negative) and shape of the bacteria pictured below. Gram-Negative; Bacillus (rod) ...

Exam (elaborations) BIOD 171

The heat fixing procedure kills the specimen. This also prevents any observations on motility and enzymatic properties. 2. What is the proper way to dispose of all materials used during the lab? All materials must be place in a biohazardous waste bag and placed into an autoclave for sterilization. 3. What are the Gram status, shape and identification of organism #2 from the Gram stain procedure? Gram-negative; Bacillus (rod); E. Coli 4. What are the Gram status, shape and identifi...

LAB 1 Answer the following questions 1. What three elements are used in an autoclave to sterilize equipment? heat, pressure, and steam 2. What is the minimum temperature an autoclave must be set at to achieve sterile condition? 125°C 3. If you are working in a lab in which an autoclave is not available, and you are pressed for time, which would you chose to best sterilize your equipment? Hot steam or hot air? Explain why you chose your answer. Hot steam is the best choice a...

QUESTIONS AND ANSWERS: Biod171 Esssential microbiology learning module 2 exam

BIOD 171 M2: Module 2 Review