BHCS Exam Questions with Complete Solutions

BHCS Exam Questions with Complete Solutions What are the 3 domains of life? - ANSWER Bacteria, Archaea - Prokaryotes Bacteria with peptidoglycan, Archaea without. Eukarya - Eukaryotes 4 types of cellular living microorganisms - ANSWER Parasites, Protozoa, Fungi, Prokaryotes 2 types of non-living acellular microorganisms - ANSWER Virus, Prions Bacteria definition - ANSWER unicellular cells that reproduce quickly and compete with host cells for space and nutrition Parasite definition - ANSWER organism that grows and feeds on a host to survive Fungi definition - ANSWER unicellular organism that attack the body surfaces Virus definition - ANSWER metabolically inert, reproduction is dependent on host machinery, acellular, morphology determined by electron microscope/genetic makeup Prion definition - ANSWER infectious abnormally folded protein capable of causing disease How do prokaryotes divide? - ANSWER binary fission How do eukaryotes transport between membranes? - ANSWER Endocytosis and exocytosis What does a phylogenetic tree show? - ANSWER evolutionary relationships and common ancestors classification of bacteria can be determined by: - ANSWER morphology (growing in agar or microscopy) structure (the gram stain) purple positive, pink negative, acid fast - 3 types of cell wall layers Gram stain method - ANSWER - the ability of stained gram-positive bacteria to resist 95% ethanol wash 1. violet stain 2. ethanol wash: gram-negative dont retain violet stain 3. Red stain - gram-positive: a. hold violet stain - gram-negative a. washed of blue stain and are counterstained red b. thin peptidoglycan cell walls inside an outer lipid layer c. alchohol dissolves the lipid and removes the dye from the walls of these bacteria Gram-positive bacteria cell wall made of (3) - ANSWER peptidoglycan - purple contains telchoic acid Gram-negative bacteria cell wall (5) - ANSWER only contains 10%peptidoglycan NO telchoic acid LPS-endotoxin stains pink High lipid content Features of binary fission (3) - ANSWER Asexual Cell doubles in mass DNA replication Only bacteria that form spores.. - ANSWER gram- positive spores covered in calcium so cannot be killed with heat/cooking/bleach Autotrophs vs. Heterotrophs - ANSWER Autotrophs - "self feeders" that produce organic compounds from light energy (key example - glucose) Heterotrophs - organisms who must obtain their energy source by ingesting or absorbing nutrients (C) from other living things 3 ways to grow microbes - ANSWER 1. Nutrient source (carbs, proteins, vitamins) 2. Broth culture (test tubes) 3. Solid media Factors to think of when growing microbes - ANSWER pH, temperature, O2 present or not, water availability, nutrient source Stages of microbial growth curve in liquid (broth) - ANSWER 1. Lag phase 2. Log phase 3. Stationary phase 4. Death/decline phase