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PASSAGE 22

In two studies publicly presented on Monday at the annual meeting of the American Society for

Biochemistry and Molecular Biology in Orlando, Florida in the United States, scientists have disclosed

new steps toward using natural adhesives made by the dusky Arion slug (Arion subfuscus) in medical

applications such as in closing skin wounds and reducing scarring.

Arion slug secretes an unusual glue, making itself a difficult target for predators. This glue remains

both sticky and flexible and works even when the surface the slug is on is wet. Previous studies have

shown that, unlike many artificial adhesives, Arion slug glue is non-toxic to mammalian tissue.

Scientist Rebecca Falconer, an Ithaca College undergraduate who led one of the two studies, said

"Typical sutures like staples and stitches often lead to scarring and create holes in the skin that could

increase the chance of infection after surgery [...] Understanding the roles of adhesive proteins in the slug

glue would aid in the creation of a medical adhesive that can move and stretch yet still retain its strength

and adhesiveness." In her set of experiments, Falconer observed eleven proteins found only in the Arion

slug glue and used DNA recombination to produce usable amounts of each of these proteins, whereas

Christopher Gallego-Lazo, also an Ithaca undergraduate, evaluated the glue by focusing on the chemical

bonds within it. Gallego-Lazo found that slight changes in these chemical bonds could alter the strength

of the slug glue.

Gallego-Lazo said, "Few studies on biological adhesives have identified the exact nature of the bonds

holding the glue together. This knowledge can guide the development of an organic synthetic adhesive

that would reduce the risk of infection and scarring compared to stitches and staples and could be applied

rapidly and simply."

(Adapted from Wikinews)

Question 1. The word “disclosed” in the passage is closest in meaning to

.

A. discovered

B. approved

C. revealed

D. proved

Question 2. The word “its” in the third paragraph refers to

.

A. slug glue

B. adhesive proteins

C. the creation

D. medical adhesive

Question 3. According to the passage, all of the following characteristics of the slug glue have been

studied by scientists EXCEPT for

.

A. Inner chemical bonds

B. Toxicity

C. Adhesive proteins

D. DNA recombination

Question 4. What is the passage mainly about?

A. New discoveries about artificial adhesives.

B. Ongoing research about a new type of organic glue.

C. The drawbacks of typical sutures.

D. Reducing the risk of infection caused by stiches and staples.

Question 5. The chemical bonds of the slug glue are being studied because

.

A. they can directly alter the strength of the slug glue.

B. they can be used to produce usable amounts of adhesive proteins.

C. they can lead to infection like stiches and staples.

D. they can provide scientists with useful information.