57) An organism is categorized in a domain according to its cell size.
58) Archaea are very similar to bacteria and have rigid cell walls made of peptidoglycan.
59) Thiomargarita namibiensis can not be a eukaryote because it is only 1 mm in width.
60) HIV/AIDS can be categorized as a new or emerging infectious disease. By putting it into this category, we are effectively saying that
A) this infection hasn't been observed in the human population prior to recent (within the last 50 years) outbreaks.
B) this disease has been in susceptible populations for centuries, but has only recently achieved infection levels that became detectable.
C) the infectious agent is still evolving and changing, unlike with older, more established diseases such as plague or polio.
D) the disease has always been in susceptible populations and causing disease, but we lacked the technology to detect it.
E) this infection hasn't been observed in the human population prior to recent (within the last 5 years) outbreaks.
61) An illness outbreak occurs in New York City birds in the late 1990s. After a lengthy scientific investigation, the Centers for Disease Control (CDC) determine that the agent causing the birds to die is the West Nile virus. Outbreaks of this illness have been observed in several other countries in Asia and the Middle East across the last 50 years, but not in the United States. With this information, what would be the best categorization of this infectious agent/disease?
A) This is a reemerging infection. It is been around for a long time, and it is reappearing in a susceptible population again.
B) This is a nosocomial (hospital-acquired) infection. It is transmitted from animals to human beings in urban environments.
C) This is an emerging infection. It hasn't been around that long, and it has made a jump across continents into a new susceptible population.
D) This is an unimportant infection that not a concern to human beings because it occurs in birds, so there is no need to classify it.
E) This is a chronic infection. It has been around for many years, and it has made a jump across continents into a new susceptible population.
62) Why are we concerned at all with monitoring emerging/reemerging diseases?
A) These represent growing threats to human health that will require new scientific research and resources to effectively combat.
B) Because globalization leads to more chances for spread of illnesses into new areas and populations. Monitoring these illnesses will help us to protect people.
C) Because the speed of travel has increased, so it is far more likely that a serious pathogen can spread rapidly across the globe. Monitoring these illnesses will help us protect populations.
D) All of the answer choices are correct.
E) None of the answer choices is correct.
63) A microbiologist obtained two pure isolated biological samples: one of a virus, and one of a viroid. The labels came off during a move from one lab to the next, however. The scientist felt she could distinguish between the two samples by analyzing for the presence of a single type of molecule. What type of molecule would she be looking for to differentiate between the two?
A) DNA
B) Protein
C) Lipids
D) RNA
E) Carbohydrate
64) A scientist has two samples—the first is a prion sample, while the second is a viroid sample. However, the samples are in unlabeled tubes. The scientist wants to run a simple analysis to determine which tube contains the prion sample and which one contains the viroid. What type of molecule would she look for to do this?
A) Lipids
B) DNA
C) Protein
D) Polysaccharides
E) Peptidoglycan
65) A scientist discovers a new species near coral reefs in Australia. He finds that this single-celled species is photosynthetic (using sunlight for energy), has a rigid cell wall structure with no peptidoglycan, uses a flagellum for motion, and contains a variety of internal structures that are membrane-bound. Given this information, this new species is most likely a(n) ________ cell in the ________ domain.
A) bacterial; Eukarya
B) fungal; Prokarya
C) viral; Archaea
D) algal; Eukarya
E) protozoan; Bacteria
66) Scientists recently cloned Louis Pasteur and put him back to work in a modern lab. He promptly developed a topical gel (used externally) that breaks down proteins. Since he hasn't been around for some time, he's unsure what the best application for his invention might be. Help him out. What pathogenic agent would this gel be most effective and safe at eliminating?
A) Viroids on the surface of agricultural plant tissues.
B) Prions inside the central nervous system of cows.