RC 5

The past decade has seen a statistically significant uptick in reports of the bacterial strains known as

"super-bugs," so called not because of enhanced virulence, but because of their resistance to many

antimicrobial agents. In particular, researchers have become alarmed about NDM-1 (New Delhi metallo-betalactamase),

which is not a single bacterial species, but a

5

transmittable genetic element encoding multiple resistance genes. A resistance "cocktail" such as NDM-1

could bestow immunity to a bevy of preexisting drugs simultaneously, rendering the bacterium nearly

impregnable.

However, in spite of the well-documented dangers posed by antibiotic-resistant bacteria, many scientists

argue that the human race has more to fear from viruses. Whereas

10

bacteria reproduce asexually through binary fission, viruses lack the necessary structures for reproduction, and

so are known as "intracellular obligate parasites." Virus particles called virions must marshal the host cell's

ribosomes, enzymes, and other cellular machinery in order to propagate. Once various viral components have

been built, they bind together randomly in the cellular cytoplasm. The newly finished copies of the virus break

through the cellular

15

membrane, destroying the cell in the process. Because of this, viral infections cannot be treated ex post facto

in the same way that bacterial infections can, since antivirals designed to kill the virus could do critical damage

to the host cell itself. In fact, viruses can infect bacteria (themselves complete cells), but not the other way

around. For many viruses, such as that responsible for the common cold sore, remission rather than cure is the

goal of currently

20 available treatment.

While the insidious spread of drug-resistant bacteria fueled by overuse of antibiotics in agriculture is

nothing to be sneezed at, bacteria lack the potential for cataclysm that viruses have. The prominent virologist

Nathan Wolfe considers human immunodeficiency virus (HIV), which has resulted in the deaths of more than

thirty million people and infected twice that

25

number, "the biggest near-miss of our lifetime." Despite being the most lethal pandemic in history, HIV could

have caused far worse effects. It is only fortunate happenstance that this virus cannot be transmitted through

respiratory droplets, as can the viruses that cause modern strains of swine flu (H1N1), avian flu (H5N1), and

SARS.

5. The main purpose of the passage can be expressed most accurately by which of the following?

(A) To contrast the manner by which bacteria and viruses infect the human body and cause cellular

damage.

(B) To explain the operations by which viruses use cell machinery to propagate.

(C) To argue for additional resources to combat drug-resistant bacteria and easily transmissible

pathogenic viruses.

(D) To highlight the good fortune experienced by the human race, in that the HIV pandemic has not been

more lethal.

(E) To compare the relative dangers of two biological threats and judge one of them to be far more

important.

6. It can be inferred from the passage that infections by bacteria

(A) result from asexual reproduction through binary fission

(B) can be treated ex post facto by antimicrobial agents

(C) can be rendered vulnerable by a resistance cocktail such as NDM-1

(D) are rarely cured by currently available treatments, but rather only put into remission

(E) mirror those by viruses, in that they can both do critical damage to the host cell

7. According to the passage, intracellular obligate parasites

(A) are unable to propagate themselves on their own

(B) assemble their components randomly out of virions

(C) reproduce themselves through sexual combination with host cells

(D) have become resistant to antibiotics through the overuse of these drugs

(E) construct necessary reproductive structures out of destroyed host cells

Questions 8–10 are based on the following reading passage.

A supernova is a brief stellar explosion so luminous that it can briefly outshine an entire galaxy. While

the explosion itself takes less than fifteen seconds, supernovae take weeks or months to fade from view;

during that time, a supernova can emit an amount of energy equivalent to the amount of energy the sun is

expected to radiate over its entire lifespan.

5 Supernovae generate enough heat to create heavy elements, such as mercury, gold, and silver. Although

supernovae explode frequently, few of them are visible (from Earth) to the naked eye.

In 1604 in Padua, Italy, a supernova became visible, appearing as a star so bright that it was visible in

daylight for more than a year. Galileo, who lectured at the university, gave several lectures widely attended by

the public. The lectures not only sought to explain the origin of

10

the "star" (some posited that perhaps it was merely "vapour near the earth"), but seriously undermined the

views of many philosophers that the heavens were unchangeable. This idea was foundational to a worldview

underpinned by a central and all-important Earth, with celestial bodies merely rotating around it.

8. The primary purpose of the passage is to

(A) give the history of supernovae

(B) describe a shift in thought as a result of a natural event

(C) juxtapose two opposing views about supernovae

(D) corroborate the view that the earth is not central to the universe

(E) explain how science and philosophy interrelate

Consider each of the answer choices separately and indicate all that apply.

9. Which of the following can be inferred by the passage?

Supernovae can take over a year to fade from view.

Prior to 1604, no one had ever seen a supernova.

Galileo convinced philosophers of the incorrectness of their views.

10. The author mentions which of the following as a result of the supernova of 1604?

(A) The supernova created and dispersed the heavy elements out of which the earth and everything on it is

made.

(B) Galileo explained the origin of the supernova.

(C) The public was interested in hearing lectures about the phenomenon.

(D) Galileo's lectures were opposed by philosophers.

(E) Those who thought the supernova was "vapour" were proved wrong.

Question 11 is based on the following reading passage.

A Small Place is Jamaica Kincaid's memoir of growing up in Antigua as well as an indictment of the

Antiguan government and Britain's colonial legacy in Antigua. Kincaid blames colonial rule for many of

Antigua's current problems, including drug dealing and selling off land for tourist properties. Kincaid's critics

question why, if the British are responsible for

5 the Antiguan government's corruption, the British government itself isn't more corrupt. Kincaid has responded

that there must have been some good people among the British, but that they stayed home.

Consider each of the answer choices separately and indicate all that apply.

11. Based on the information in the passage, which of the following would Kincaid most likely agree with?

A government can bring about a degree of corruption abroad that the government itself does not suffer

from at home.

Britain has caused corruption in governments throughout its former colonial empire.

Selling off land for tourism-related purposes is a problem for Antigua.