Exam 1 Microbiology 2060 | Salt Lake Community College, Latest 2025/2026 Graded A

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Microbiology Exam 1 Microbiology 2060 | Salt Lake Community College • Which of the following are FALSE concerning microbes? Microbes produce vitamins in the intestines. Microbes play a role in ... breaking down waste and decomposing dead organisms. The primary role of microbes on the planet involves causing disease in animals and humans. Microbes generate oxygen through photosynthesis. • Correct format for the scientific name? Staphylococcus aureus STAPHYLOCOCCUS AUREUS Staphylococcus Aureus Staphylococcus aureus • Consider organisms that are eukaryotic, are found in both unicellular and multicellular forms, may resemble plants but are not photosynthetic, have chitin in their cell walls, and absorb organic nutrients from decomposing material in the environment. These organisms would be classified as which of the following types of organisms? bacteria protozoa fungi archaea • Which of the following matches the organisms described with the correct domain? eukarya--single-celled and multicellular organisms, with a defined nucleus and a variety of nutritional sources bacteria--unicellular, eukaryotic organisms that always lack cell walls bacteria--unicellular, eukaryotic organisms with cell walls that do not contain peptidoglycan archaea--multicellular, eukaryotic organisms that do not have cell walls • How was disproving spontaneous generation associated with developing principles important to microbiology? Pasteur's experiments with swan-necked flasks supported the concept that microbes in the air were responsible for contaminating nonliving matter. Spallanzani disproved spontaneous generation through his experiment, in which flasks of meat broth were boiled and then melted shut, preventing the passage of air altogether. Needham disproved spontaneous generation through his experiments, in which boiled flasks of broth, when covered, became cloudy, teeming with microorganisms after a few days. Proving spontaneous generation confirmed the existence of microbes. • The observations of Hooke and van Leeuwenhoek documenting the existence of microscopic cells formed the basis of what important theory? the theory of chemotherapy, or use of antimicrobials to destroy pathogenic organisms the germ theory of disease and causative agents the cell theory, stating that all living things are composed of cells the theory of spontaneous generation, which held that life forms could arise spontaneously • A disease breaks out among sheep in California. A scientist takes blood from the sheep and grows a previously unknown organism. That organism is then injected into a healthy sheep. The healthy sheep becomes sick with the same symptoms as the original sheep and dies. That sheep's blood is then cultured, and the original organism is isolated. This applies the principles of __________. vaccination Koch's postulates spontaneous generation epidemiology • Which of the following is true about antibiotics? In some cases, antibiotics are able to kill pathogenic microbes without harming human cells. Antibiotics are effective against viruses. Although some antibiotic resistance has been reported, it is not considered a real problem in medicine today. Antibiotics are unaffected by enzymes. • Disproving the theory of spontaneous generation- Ch 1 Q 9 Which of the following is true of microbes? Microbes create pollutants and toxins that harm the environment. 99% of all microbes are pathogenic. Gene expression in bacteria is very similar to gene expression in humans, which facilitates the use of bacteria in recombinant biotechnology and gene therapy. All bacterial enzymes are harmful to humans and the environment. • All of the following factors contribute to the threat of emerging infectious diseases (EIDs) EXCEPT __________. spread of known diseases to new geographic regions or populations by modern transportation vaccinations that control epidemiologic spread evolutionary changes to existing organisms through genetic changes increased human exposure to new, unusual infectious agents in areas that are undergoing ecological changes, such as deforestation and construction • Microorganisms are involved in each of the following processes EXCEPT decomposition of organic material. O2 production. food production. smog production. infection. • Each of the following organisms would be considered a microbe EXCEPT protozoan. bacterium. virus. mushroom. yeast. • The term used to describe a disease-causing microorganism is pathogen. virus. microbe. bacterium. infection. • Microbes are associated with life-sustaining benefits as well as life-threatening diseases. True False • In the name Staphylococcus aureus, aureus is the domain name. kingdom. species. genus. family name. • A prokaryotic cell may possess each of the following cellular components EXCEPT flagella. a nucleus. a cell membrane. a cell wall. ribosomes. • Which of the following is NOT associated with viruses? nucleic acid protein coat organelles envelope chemical reactions • Viruses are not considered living organisms because they are structurally very simple. cannot reproduce by themselves. are ubiquitous in nature. are typically associated with disease. can only be visualized using an electron microscope. • The infectious agent that causes AIDS is a mold. protozoan. bacterium. yeast. virus. • Which of the following is NOT a domain in the three-domain system? bacteria archaea animalia eukarya • A student has obtained a sample of pond water for study. Using the high-power lens, he observes several cells with nuclei. He can conclude that the cells are NOT bacteria. True False • All cells possess a cell wall. True False • The first step for directly linking a microbe to a specific disease according to Koch's postulates is to compare the blood of a sick animal to blood obtained from a healthy animal. culture the blood or other body fluid from a diseased animal using nutrient medium. inject a sample of blood or other body fluid from a diseased animal into a healthy animal. isolate microbes from the blood of healthy animals. obtain a sample of blood or other body fluid from a diseased animal. • In which of the following situations would Koch's postulates be utilized? formulation of a vaccine against a new pathogen in a genetic engineering lab development of a new antibiotic in a pharmaceutical lab determination of the cause of cancer in a patient whenever the scientific method is used to investigate a microbiological problem determination of the cause of a new emerging disease by scientists studying disease transmission • Which disease has been eliminated through the use of vaccines? measles smallpox influenza rubella tuberculosis • Spontaneous generation refers to living cells arising only from other living cells. True False • Infectious disease is almost totally eradicated in our world. True False • All pathogens known to infect humans have been identified at this point in time. True False • As yet, no members of Domain __ have been shown to cause disease in humans. Archaea Protista Eukarya Monera Bacteria • Some members of Domain __ fix nitrogen. Archaea Protista Eukarya Monera Bacteria • Cryptosporidium is a member of Domain __. Archaea Protista Eukarya Monera Bacteria • What is the type of weak bond between the hydrogen of one molecule and the nitrogen of anothermolecule, where the two don't actively share an electron? covalent bond disulfide bond hydrophobic bond ionic bond hydrogen bond • What is the type of strong chemical bond between carbon, hydrogen, and oxygen atoms in a single organic molecule? covalent bond ionic bond hydrogen bond • The equation below is what type of reaction? Molecule AB → Molecule A + Molecule B exchange reaction synthesis reaction reversion reaction decomposition reaction • The formation of ADP from ATP can be defined as a hydrolytic reaction. True False • Identify the following reaction: Glucose + Fructose → Sucrose + Water dehydration synthesis reaction hydrolysis reaction exchange reaction reversible reaction ionic reaction • Identify the following reaction: Lactose + H2O → Glucose + Galactose dehydration synthesis reaction hydrolysis reaction exchange reaction reversible reaction ionic reaction • Which type of molecule contains -NH2 (amino) groups? protein carbohydrate nucleic acid triglycerides • Which of the following statements regarding protein structure is FALSE? Quaternary structures involved multiple polypeptides. The primary structure is formed by covalent bonding between amino acid subunits. Tertiary structures are formed only from covalent bonds. Secondary structures are formed only from hydrogen bonds. • Structurally, ATP is most like which type of molecule? carbohydrate lipid protein nucleic acid • What do genes consist of? carbohydrates lipids proteins nucleic acids • Which molecule is composed of a chain of amino acids? carbohydrate lipid protein nucleic acid • Radioisotopes are frequently used to label molecules in a cell. The fate of atoms and molecules in a cell can then be followed. Assume Saccharomyces cerevisiae is grown in a nutrient medium containing the radioisotope 35S. After a 48-hour incubation, the 35S would most likely be found in the S. cerevisiae's water. nucleic acids. proteins. lipids. carbohydrates. • Starch, dextran, glycogen, and cellulose are polymers of nucleic acids. acids. glucose. fatty acids. amino acids. • Protein structure is directly related to the function of the protein. Which of the following is an accurate description of the level of structure in a protein? Primary protein structure refers to the polypeptide chain folds that give a protein a unique shape. Quaternary protein structure is the localized, repetitive twisting or folding of the polypeptide chain. Secondary structure is the unique sequence of amino acids linked together. Tertiary protein structure is the overall three-dimensional shape involving interactions between various amino acids and their side groups. • Which of the following is true of ATP? ATP is a nucleic acid. ATP is the principal energy-storing molecule in the cell. ATP stores energy in phosphate bonds. ATP represents an unlimited energy supply for cells. • Some viruses have a genome consisting of double-stranded RNA. How could you distinguish between the genome of this virus and a virus containing double-stranded DNA? Analysis of the genome sequence would reveal different nitrogenous bases in the RNA virus as compared to the DNA virus. Structural analysis would reveal phosphate linkages between the sugar groups of DNA virus genomes, but not in RNA viruses. The double-stranded DNA genome could not be distinguished from double-stranded RNA due to their extreme similarity. The double-stranded DNA viral genome would be longer. • If an arrow were drawn between "DNA" and "mRNA," which of the following would be the best label? is translated into is transcribed into is bound to is modified into • DNA and RNA share which of the following characteristics? Both contain uracil. Both are made, in part, of nitrogenous bases and sugars. Both have the same type of sugar backbone. Both are double stranded. • Structure of DNA- Ch 2 Q 17 Which of the following places the steps of the Gram stain in the correct order? 1-Alcohol-acetone2-Crystal violet3-Safranin4-Iodine 1-3-2-4 2-4-1-3 1-2-3-4 2-1-4-3 4-3-2-1 • The purpose of a mordant in the Gram stain is to prevent the crystal violet from leaving the cells. remove the simple stain. make the bacterial cells larger. make the flagella visible. make gram-negative cells visible. • You are performing a Gram stain on gram-positive bacteria and you stop after the addition of the first dye. What is the appearance of the bacteria at this point? purple red colorless brown • You are performing a Gram stain on gram-negative bacteria and you stop after the addition of the mordant. What is the appearance of the bacteria at this point? purple red colorless brown • You are performing a Gram stain on gram-negative bacteria and you stop after the decolorizer step. What is the appearance of the bacteria at this point? purple red colorless brown • You are performing a Gram stain on gram-positive bacteria and you stop after the addition of the counterstain. What is the appearance of the bacteria at this point? purple red colorless brown • Which step in the Gram stain is the critical step in differentiating gram-positive cells from gram-negative cells? iodine safranin crystal violet alcohol-acetone • What is the role of iodine in the Gram stain process? Iodine is a pink dye that acts as the primary stain in the Gram stain technique. Iodine is a mordant in the Gram stain technique, which functions to intensify the primary stain. Iodine is the decolorizer removing the primary stain after the first step in the Gram stain technique. Iodine is a basic purple dye, which acts as the primary stain in the Gram stain technique. • A student creates a Gram stain on a bacterial sample that has a mix of gram-negative and gram-positive organisms. The student accidentally forgets the decolorizer step. What would the outcome of the Gram stain be? All organisms would appear purple (gram-positive). All organisms would appear colorless. All organisms would appear pink (gram-negative). The Gram stain would show pink (gram-negative bacteria) and purple (gram-positive bacteria). • Consider the following situations, and determine when a simple stain could be used instead of a Gram stain. A microbiologist is trying to determine whether a specimen contains bacteria or fungi. An unknown species of bacteria is being characterized and identified. A specimen is suspected to contain multiple species of bacteria. A wound specimen is being examined. • In a completed Gram stain, gram-negative bacteria are colorless. True False • In a completed Gram stain, gram-positive bacteria are purple. True False • While staining a mixed culture of Gram-positive and Gram-negative bacteria, switching the order of steps 2 and 3 would result in ______________________. all bacteria appearing pink all bacteria appearing purple a change in the Gram reaction; Gram-negative cells would appear purple while Gram-positive cells would appear pink. all bacteria appearing clear • Which structural feature of Gram-positive bacteria enhances their ability to retain the crystal violet dye? a thin peptidoglycan layer an outer membrane a thick peptidoglycan layer All of the above contribute to a Gram-positive cell's ability to retain crystal violet. • What would you anticipate seeing if you accidentally switched crystal violet and safranin while performing a Gram stain? Gram-positive bacteria would appear pink and Gram-negative bacteria would appear purple. Gram-positive bacteria would appear purple and Gram-negative bacteria would appear pink. All bacteria would appear pink. All bacteria would appear purple. • What would you expect to see if you forgot to perform step 2 of the Gram stain procedure? All bacteria would appear pink. Gram-positive cells would appear purple and Gram-negative cells would appear pink. All bacteria would appear purple. Gram-positive cells would appear pink and Gram-negative cells would appear purple. • Which of the following statements is INCORRECT regarding prokaryotic cells? They reproduce by binary fission. They typically have a circular chromosome. They lack membrane-enclosed organelles. They lack a plasma membrane. Their DNA is not enclosed within a membrane. [Show More]

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