BI101J, UNSEEN LIFE ON EARTH—MIDTERM EXAM 3 Antibiotic resistance is * a technique used by microbes for evading antibiotics. an intolerance among the sick to an antibiotic. of little concern. all of the above none of the above Method(s) of becoming resistant to antibiotics include horizontal gene transfer. alter methods of cell wall formation. pump out the antibiotic as fast as it enters the cell. * all of the above none of the above Antibiotics are often discovered within moon rocks. * microbes themselves. fossils. old socks. ostriches. Evaluate this statement: New antibiotics will be sufficient to save us from antibiotic-resistant bugs. * False; microbes will continue to evolve resistance mechanisms whenever they face antibiotics. Additional measures need to be taken to minimize the likelihood of additional antibiotic resistance arising. False; the new antibiotics aren’t as effective as the old. False; just because there is no research ongoing to develop new antibiotics. True; we need new antibiotics urgently. True; new antibiotics will eradicate currently known disease organisms. Bioremediation with methanotrophs may accomplish the removal of methane from the atmosphere. the rapid increase of methane in Earth’s atmosphere. * the degradation of highly toxic recalcitrant molecules. exacerbation of an already troublesome problem. excessive flatulence. Composting the garbage from your town in the landfill * could reduce the amount of contaminated liquids draining out of the dump. could produce a product safe for use on food-producing farms. could increase the population of methanotrophs to dangerous levels. all of the above none of the above Contact bacterial diseases occur by inhalation of the aerosol mist produced by sneezes. * shaking hands, kissing, touching. bites from infected mosquitoes or ticks. weakened immune systems. all of the above Hansen’s disease causes * skin nodules, deformity, loss of sensation. swelling of the glands in the throat. reddened, thickened and peeling skin. a tendency to fall asleep during the day. all of the above Bacteria in the chlamydiae and rickettsiae groups will grow in damaged or dead cells. * living tissue only. fungi, but not animals. other bacteria only. viruses. What is the likely source of an infection that causes these symptoms: fever, abdominal cramps, nausea, vomiting, diarrhea, and dehydration? polio snails * ingested foodborne or waterborne bacteria such as E. coli, Campylobacter, or Shigella mosquitoes rats or mice Viral entry into a cell and multiplication within that cell is likely to result in * death of the infected cell. mutations. destruction of the cell’s mitochondria or chloroplasts. all of the above none of the above One difference between the ailments caused by viruses and bacteria is that virus, but not bacterial infections produce fevers. feed a cold, starve a fever. * viruses invade and kill cells from within, while bacteria often produce a cell-killing toxin. all of the above none of the above Wearing a protective mask over the nose and mouth ________ help prevent infection with rubella * would would not none of the above Yellow fever and dengue fever ________ transmitted to people by mosquitoes * are are not none of the above A denatured protein is a mutant, unnatural protein. * one whose shape has been changed so that it is no longer capable of performing its function. a scrambled mess of DNA. a confused ribosome. a product of mitochondria. Which of the following might be used as antiseptics? * a germicide applied to living tissue chlorine ethylene oxide heat at 121° C all of the above Pickling can preserve fruits or vegetables because the food is heated to sterilize the product. heated to pasteurize the product. * dehydrated by the addition of salt and / or sugar. refrigerated. frozen. Ultraviolet wavelengths of light may cause you to develop tanned skin, but it also * damages your DNA, as well as that of microbes. Such damage may destroy the cell, or may cause mutations. causes increased blood pressure. causes decreased blood pressure. causes bacteria on the skin to rapidly expand their populations. causes a rapid expansion of viruses. Pasteurization raises the temperature of foods ________ than canning. higher * lower there is no difference in the temperature – pressure, however is raised to a higher level by pasteurization Nosocomial infections are most frequently transmitted by * catheterization and surgical equipment. sexual contact. aerosol droplets. insects. contaminated food or water. The use of Agrobacterium tumefaciens to insert genes into a plant cell is an example of * genetic engineering. the infectious nature of some viruses. a pandemic. an epidemic. none of the above Cassava mosaic virus may be transmitted by grafting. white flies. contact of roots. * all of the above none of the above Cassava mosaic virus causes intestinal upset and diarrhea. high fever and encephalitis. * damage to the plant’s photosynthetic parts. destruction of the patient’s immune system. none of the above Genetic engineering resistance to the cassava mosaic virus * could help prevent famine. could help prevent thousands of cases of encephalitis. could prevent the transmission of several mosquito-borne diseases. could prevent the contamination of the water supply. could produce new antibiotics. Resistance to pesticides is similar to strong moral development. old socks. ostrich eggs. * antibiotic resistance. none of the above The use of microbes as agents of warfare is a very old practice. includes the use of smallpox-carrying blankets given to Native Americans. includes the dumping of dead animals into wells. * all of the above none of the above A greater understanding of microbes may help us to remove toxic wastes from the environment. feed more people. create edible vaccines. create new antibiotics. * all of the above Eighty percent of the material (excluding water) inside a cell is composed of * proteins. DNA. RNA. lipids. carbohydrates. Proteins function as structural components that form and support cells and organs. catalysts that speed up chemical reactions. control and manage the rate of chemical reactions. control and manage the functioning of DNA. * all of the above HIV infection may be detected by * a reduction in the number of T-lymphocytes. the onset of fever within a few days of infection. an increase in the production of enzymes in the gut. liver destruction. none of the above Full-blown AIDS results in death most often because of the removal of bone calcium (=osteoporosis). * the immune system is unable to defend against opportunistic infections of fungi, bacteria and protozoans. the immune system overproduces T-lymphocytes. underproduction of red blood cells (acute anemia). none of the above AIDS may also affect the central nervous system, causing * personality changes, dementia, intellectual incapacity. nerve deafness. Parkinson’s disease (hand tremors and difficulty walking/speaking). stroke. none of the above The protozoan organism, Trypanosoma, reproduces in the gut. * cerebrospinal fluid. snails that transmit the disease. kidney. heart. Reproduction of Trypanosoma results in * infection and inflammation of the material surrounding the brain. heart attacks. stroke. Kaposi’s sarcoma. none of the above. The skin is considered * the first line of defense against infection with unfriendly bugs. relatively unimportant as a defense against infection. the source or red blood cells. the source of white blood cells. none of the above The functions of macrophages include production of HIV. production of more red blood cells. production of more skin cells. * recognize, engulf, and digest invader cells. essential for the proper functioning of the mucociliary elevator. Critique this sentence: Lymphocytes recognize specific invaders. * True; molecules on their cell surfaces match and lock on to specific antigens. True; macrophages recognize the unique DNA of the invading bug. False; macrophages are nonspecific. False; macrophages do not have an immune system function. none of the above Vaccines are effective because they provide a supply of educated macrophages. provide a supply of red blood cells. provide a supply of new skin cells for the production of educated lymphocytes. * educate the immune system by providing noninfectious molecules or weakened organisms that stimulate the immune system to make lymphocytes. none of the above Emergent diseases are * ones to which we have had little or no prior exposure. ones that cause some pock marks to appear on the skin. ones that affect people that live in wet areas. ones that are vectored by mosquitoes. ones that are vectored by rodents. The discovery of the disease reservoir of an emerging disease, such as the Ebola virus, would enable us to learn how reservoirs are contaminated. prevent nosocomial infections. end the AIDS pandemic. * learn where the pathogens are maintained between infections. all of the above Toxins increase the pathogenicity of microorganisms by * altering the metabolism of cells, tissues, or organs of the host’s body. educating the host’s immune system. increasing the formation of T-cells and macrophages. increasing the formation of new bacterial cell wall material. increasing the production of bacterial mitochondria. Exotoxins are found in strictly anaerobic bacteria only. * proteins toxic to the host that are produced by gram-negative bacteria. They are produced inside the bacterial cell, then released by normal cell activities. found in strictly aerobic bacteria only. found in extremophiles only. found in the cell walls of animals. Endotoxins are * cell wall components of gram-negative bacteria. They are released when the bacterium dies or is digested by another cell. found in the cell walls of animals. found in the nuclear envelope of bacteria. found in the mitochondria of bacteria. none of the above Critique this sentence: “I think this 2-week old spaghetti will be OK if I just bring it to the boiling point for a few minutes. That’ll kill any bacteria present and it will then be safe to eat.” This is a reasonable approach to the problem of old food. It would be ok, but only if the boiling was done in a pressure cooker so the temperature was raised to 121° centigrade. It would be ok if the food was pasteurized. * Bad idea: bacterial endotoxins or exotoxins will still be present and the food will still make you sick. none of the above Critique this sentence: The human skin is a relatively microbe-free environment. * False; the skin is home to many bacteria and fungi. False; the skin is home to some extremophile bacteria. False; the skin is colonized by anaerobic fungi. True; the skin is colonized by few, if any microorganisms. True; the skin is colonized by microbes, but no microbes. What’s wrong with waiting until morning to put the dinner leftovers away? * Airborne fungi and bacteria will have ample time to land on and colonize the food. Growth will begin in the warm food. Nothing’s wrong with the idea. Come on - lighten up! Most homes are free of airborne microbes, so it’s a fine idea. all of the above none of the above If you were to make your own yogurt, you would be growing mostly anaerobic heterotrophic bacteria. Should you shake up the mixture periodically to mix in oxygen? Yes; these bacteria will grow more quickly with the addition of oxygen. Yes; the oxygen will be used in the process of photosynthesis. Yes; the oxygen will be used in the process of cell respiration. * No; anaerobic bacteria grow in the absence of oxygen. none of the above Various strains of the yeast Saccharomyces cerevisiae are used for brewing beer and wine. The starting material is a sugar-rich extract from grains or fruits. Would you advise the beginning brewer to brew in a container open or closed to the air? Why? * Closed; that will prevent contamination with airborne bacteria and fungi. Closed; that will prevent the introduction of unwanted carbon dioxide. Closed; that will allow the process of photosynthesis to proceed undisturbed. Open; that will allow colonization by helpful microorganisms such as airborne Escherichia coli. Open; that will allow colonization by helpful organisms such as Yersinia and Clostridium. Which of the following might be used to cleanse a brewing container? a germicide dilute bleach (this denatures proteins) something designed to kill bacteria and other microbes a surfactant (this dissolves cell membranes) * all of the above Microbiology is the study and appreciation of * viruses, archaea, bacteria, fungi, protists, and microscopic animals. old socks and spam. spam, coots, ostriches, and spam. swans, spam, ducks, spam, spam, and geese. spam, spam, spam, whales, spam, and dolphins.