BIOD171 Portage Learning Microbiology Lab Exam 3 – 12 Questions and Answers on Gram Staining, Wet Mounts and Bacterial Identification

This document contains 12 exam-style microbiology laboratory questions with verified answers designed for students preparing for BIOD171 Microbiology Lab Exam 3 in the Portage Learning program offered through Geneva College. The material focuses on key laboratory techniques used in introductory microbiology courses, particularly those related to bacterial staining, microscope slide preparation, and microbial identification procedures. The study guide reviews important lab concepts such as the steps used to prepare a dry mount slide, the purpose of cleaning microscope slides before specimen application, and the wet mount technique used to observe bacterial motility. It also explains the Gram staining procedure, including why Gram-positive bacteria retain crystal violet dye due to their thick peptidoglycan cell wall structure. Additional questions examine bacterial morphology and classification, requiring students to identify organisms based on Gram status and shape, such as Gram-negative bacillus and Gram-positive cocci chains like Streptococcus. Further topics covered in the document include the negative staining technique using nigrosin dye, why bacterial cell membranes repel negatively charged dyes, and the laboratory limitations of heat fixing samples, such as the loss of motility and enzymatic observations. The document also includes questions on proper microbiology laboratory safety procedures, including disposal of contaminated materials using biohazard bags and sterilization in an autoclave. These concepts align with core microbiology laboratory training presented in introductory microbiology textbooks such as “Microbiology: An Introduction” by Gerard J. Tortora, Berdell R. Funke, and Christine L. Case, which is commonly used alongside Portage Learning microbiology coursework. This document may be useful for students enrolled in courses such as: BIOD171 Microbiology – Portage Learning Microbiology Laboratory Introductory Microbiology Lab Microbiology for Nursing Microbiology for Allied Health General Microbiology Laboratory It is particularly relevant for: Nursing students completing microbiology prerequisites Pre-medical, pre-pharmacy, and health science students Biology or microbiology majors studying laboratory methods Allied health students in programs such as medical laboratory science, physician assistant studies, or public health Online students completing the Portage Learning microbiology lab component through Geneva College Because the questions are structured as concise exam prompts followed by clear answers, this resource is ideal for quick laboratory exam review, concept reinforcement, and preparation for microbiology practical assessments. Keywords portage microbiology lab exam 3 questions, BIOD171 microbiology lab exam 3, microbiology lab exam questions answers, gram stain procedure microbiology, gram positive vs gram negative bacteria, crystal violet gram stain, peptidoglycan cell wall bacteria, wet mount technique microbiology, dry mount slide preparation steps, negative stain nigrosin microbiology, bacterial motility microscopy, bacillus rod shaped bacteria identification, cocci chain streptococcus identification, bacterial morphology identification, microbiology slide preparation lab, heat fixing bacteria microscopy, microbiology lab safety autoclave disposal