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The Food and Drug Administration has recently proposed severe restrictions on the use of antibiotics to promote the health and growth of meat animals. Medications added to feeds kill many microorganisms but also encourage the appearance of bacterial strains that are resistant to anti-infective drugs. Already, for example, penicillin and the tetracvlines are not as effective therapeutically as they once were. The drug resistance is chiefly conferred by tiny circlets of genes, called plasmids, that can be exchanged between different strains and even different species of bacteria. Plasmids are also one of the two kinds of vehicles (the other being viruses) that molecular biologists depend on when performing gene transplant experiments. Even present guidelines forbid the laboratory use of plasmids bearing genes for resistance to antibiotics. Yet, while congressional debate rages over whether or not to toughen these restrictions on scientists in their laboratories,little congressional attention has been focused on an ill-advised agricultural practice that produces known deleterious effects.
In the passage, the author is primarily concerned with
A.discovering methods of eliminating harmful microorganisms without subsequently generating drug-resistant bacterial
B.explaining reasons for congressional inaction on the regulation of gene transplant experiments
C.describing a problematic agricultural practice and its serious genetic consequences
D.verifying the therapeutic ineffectiveness of anti-infective drugs
E.evaluating recently proposed restrictions intended to promote the growth of meat animals
According to the passage, the exchange of plasmids between different bacteria can result in which of the following?
A.Microorganisms resistant to drugs
B.Therapeutically useful circlets of genes
C.Anti-infective drugs like penicillin
D.Viruses for use by molecular biologists
E.Vehicles for performing gene transplant experiments
It can be inferred from the passage that the author believes that those in favor of stiffening the restrictions on gene transplant research should logically also
A.encourage experiments with any plasmids except those bearing genes for antibiotic resistance
B.question the addition of anti-infective drugs to livestock feeds
C.resist the use of penicillin and tetracyc-lines to kill microorganisms
D.agree to the development of meatier live-stock through the use of antibiotics
E.favor congressional debate and discussion of all science and health issues
The author's attitude toward the development of bacterial strains that render antibiotic drugs ineffective can best be described as
A.indifferent
B.perplexed
C.pretentious
D.insincere
E.apprehensive
