6. Which one of the following, if true, would most strengthen an argument of the opponents of rDNA technology?
After thirty years of investigation into cell
genetics, researchers made startling discoveries in
the 1960s and early 1970s which culminated in the
development of processes, collectively known as
(5) recombinant deoxyribonucleic acid (rDNA)
technology, for the active manipulation of a cell’s
genetic code. The technology has created excitement
and controversy because it involves altering
DNA—which contains the building blocks of the
(10) genetic code.
Using rDNA technology, scientists can transfer
a portion of the DNA from one organism to a
single living cell of another. The scientist chemically
“snips” the DNA chain of the host cell at a
(15) predetermined point and attaches another piece of
DNA from a donor cell at that place, creating a
completely new organism.
Proponents of rDNA research and development
claim that it will allow scientists to find cures for
(20) disease and to better understand how genetic
information controls an organism’s development.
They also see many other potentially practical
benefits, especially in the pharmaceutical industry.
Some corporations employing the new technology
(25) even claim that by the end of the century all major
diseases will be treated with drugs derived from
microorganisms created through rDNA technology.
Pharmaceutical products already developed, but
not yet marketed, indicate that these predictions
(30) may be realized.
Proponents also cite nonmedical applications
for this technology. Energy production and waste
disposal may benefit: genetically altered organisms
could convert sewage and other organic material
(35) into methane fuel. Agriculture might also take
advantage of rDNA technology to produce new
varieties of crops that resist foul weather, pests,
and the effects of poor soil.
A major concern of the critics of rDNA research
(40) is that genetically altered microorganisms might
escape from the laboratory. Because these
microorganisms are laboratory creations that, in
all probability, do not occur in nature, their
interaction with the natural world cannot be
(45) predicted with certainty. It is possible that they
could cause previously unknown perhaps incurable,
diseases. The effect of genetically altered
microorganisms on the world’s microbiological
predator-prey relationships is another potentially
(50) serious problem pointed out by the opponents of
rDNA research. Introducing a new species may
disrupt or even destroy the existing ecosystem. The
collapse of interdependent relationships among
species, extrapolated to its extreme, could eventually
(55) result in the destruction of humanity.
Opponents of rDNA technology also cite ethical
problems with it. For example, it gives scientists the
power to instantly cross evolutionary and species
boundaries that nature took millennia to establish.
(60) The implications of such power would become
particularly profound if genetic engineers were to
tinker with human genes, a practice that would
bring us one step closer to Aldous Huxley’s grim
vision in Brave New World of a totalitarian society
(65) that engineers human beings to fulfill specific roles.