Microbes in Human Welfare Questions and Answers

Mannitol salt agar (MSA) medium is used to select Gram-positive from Gram-negative bacteria.

According to the U.S. Pharmacopeia, what is a Controlled Room Temperature? Any temperature between 46° and 59⁰ F Any temperature between 86° and 104° F A temperature prevailing in a working area A temperature maintained thermostatically between 68° and 77° F with brief deviations between 59° and 86° F

What is the evidence of motility that is visible in SIM medium in the presence of a bacterium with flagella? A Diffuse zone of growth flaring from the line of inoculation B) Growth in the upper half of the medium C) Growth in the lower half of the medium D Growth only on the surface of the medium

Which of the following is true of a bacterial species that produces dark pink colonies when grown on MacConkey agar? A They are glucose fermenters B They are lactose fermenters C They produce urease D They reduce nitrate to nitrite

Enzymes are all around us and absolutely necessary for life. Take a picture of a food, cosmetic, etc. label and circle all the enzymes that you can identify by suffix - ase. Then Google one of the enzymes to find out what it does. Post a picture of the marked up label and the enzyme function.

The small intestine bacteria, while inhabiting areas optimal for growth, have a doubling time of roughly h (h= a your assigned number) hours. A normal small intestine starting population would be approximately 10K bacteria per ml of fluid. a. Write an equation to model this exponential growth, with b(x) representing the number of bacteria per ml and x representing the time in hours. b. How long will it take for there to be 100K bacteria per ml? (Round your answer to two decimal places if necessary) c. Determine the average rate of change between 20 hours and 30 hours.

You should know the details of all these experiments Griffith's experiment Avery McCleod and McCarthy Hershey and Chase Messelsson and Stahl

Bacteria X has an ID50 of 10 and can cause disease in individuals who are otherwise healthy. Bacteria Y has an ID50 of 10,000 and only causes disease in individuals who are already immunocompromised. Match the following statements with the best option. You can use each option more than once. Primary pathogen Opportunistic pathogen More infectious

A virus consists of nucleic acid (DNA or RNA) encased in a protein shell separating its nucleic acid from the rest of the environment. Some viruses carry a couple of enzymes with them in their shell, but they don't usually have anything else (no nucleus, no endoplasmic reticulum, no ribosomes, no RNA polymerase, no mitochondria, NO organelles at all). Which of the following characteristics of life does the virus possess? Can reproduce by itself Uses Tupperware to organize itself Can process energy None of the above

Select the microorganism that is least resistant to chemical and physical control measures. Protozoan cysts Enveloped viruses Gram-negative bacteria Nonenveloped (naked) viruses Gram-positive bacteria

Which control method would not be a suitable choice for killing Mycobacterium in a capped culture tube? Ultraviolet (germicidal) light Gamma rays 121°C at 15 psi for 15 minutes 160°C for 2 hours All of the choices would kill Mycobacterium in a culture tube.

The advantage of using ethylene oxide as a sterilant over moist heat sterilization in an autoclave is that it kills endospores, whereas the autoclave will only kill vegetative cells it is much safer for humans to work with ethylene oxide than to operate an autoclave it can be used to sterilize plastics that would melt in an autoclave All of the choices are reasons to preferentially use ethylene oxide as a sterilant

Ampicillin, amoxicillin, mezlocillin, and penicillin G all ... target the cell wall have resistance to the action of penicillinase are semisynthetic have an expanded spectrum of activity All of the choices are correct.

In general, animal viruses can enter the host cell by: A) injecting their DNA or RNA into the host cell B) endocytosis C) fusion D) B and C are both possible E)none of the above

Penicillinases are enzymes produced by bacterial cells, usually after acquiring a new gene, that _______. hydrolyze the B-lactam ring of penicillins and cephalosporins, rendering them ineffective pump the penicillins out of the cell as soon as they enter prevent the drug from crossing the cell membrane block the target binding site of the drug, rendering it ineffective

The cellular basis for bacterial resistance to antimicrobials include... bacterial chromosomal mutations synthesis of enzymes that alter drug structure prevention of drug entry into the cell alteration of drug receptors on cell targets All of the choices are correct.

The process of using a cleansing technique to mechanically remove and reduce microorganisms and debris to safe levels is disinfection sterilization antisepsis sanitization degermation

Choose the term that describes a bacteriophage infection in which the bacteriophage DNA is inserted into the host cell DNA as a prophage, and the infected bacteria can continue to grow and divide. Lysogenic Hemorrhagic Lytic Oncogenic Transforming

The Mechanism of Phagocytosis Chemotaxis: Chemical signals attract phagocytes to microorganisms Adherence: Attachment of a phagocyte to the surface of the microorganism Ingestion (Opsonization): microorganism is coated with serum proteins (Complement proteins and antibodies), making ingestion easier Digestion: Microorganism is digested inside a phagolysosome Discharge

A bacterial colony... is visible only using a microscope can consist of a mix of 2 or more types of bacteria consist of millions of genetically identical cells, all derived from an original bacterium that reproduced many times is generated by sexual reproduction of a single bacterium

2. Microbes are important in our lives because... O A. they are used to produced food such as cheese, yogurt, bread, etc. OB. they produce important chemical products such as ethanol, acetone, enzymes and vitamins OC. they decompose organic waste and incorporate nitrogen D. they help with the digestion of food O E. All of the above

Which one of the following is the appropriate vector of choice for gene therapy? bacteria protozoa viruses fungi helminthes

Staphylococcus aureus is a non-endospore former used to examine the germicidal effects for UV light True False

The Kirby-Bauer test identifies agents that can be used to fight specific bacteria. True False

The process of determining proteins expressed in a cell is a. reverse genetics b. metagenomics c. proteomics d. bioinformatics e. forensic microbiology