The MCAT®

Question 3

What is the ratio of cation to enzyme in the spectroelectrochemical experiments described in the passage?

A. 1:2

B. 2:1

C. 20:1

D. 200:1

As accustomed as we have become to the idea that scientists “construct” theories and “produce” explanations, and regardless of the controversies among scientists, the fact remains that they only disclose to us a world that came into being without the sciences or other human contributions. Galileo may have conceptualized and formalized the phases of Venus, but the phases themselves had manifestly always existed. Galileo’s fabricated hypothesis simply became the acknowledged fact. By contrast, in conceptualizing technological projects, engineers produce fictions. The technology concerned does not, and by definition could not, exist, since it is in the project phase.

This tautology frees the analysis of technological proposals from the burden of confirmation necessary in the analysis of scientific hypotheses. One might argue, of course, that Diesel did not create the principles he applied in his engine any more than Galileo created the astronomical principles he observed, and some would even contend that the engine was therefore as much beyond the control of Diesel as Venus was beyond the control of Galileo. Even so, few would seriously defend the proposition that the diesel engine had always existed and needed only to be discovered. In reference to technology, Platonism is considered an extreme philosophical stance.

The rejection of Platonism means greater freedom for those who study machinery than for those who study nature. The big issues of reality and plausibility do not bother the former. Engineers may freely create fictions, since the projection of a technological possibility from the present, or from five or fifty years in the future, to a time tₓ is a part of their job. They invent a nonexistent means of transportation, with paper passengers, opportunities yet to be created, hypothetical places to be served (often to be themselves designed from scratch), new component industries, an assumed technological revolution. They are novelists, with one difference: Their project, although initially indistinguishable from a novel, will either remain a possibility in a file or be transformed into an object.

At first, projects and the objects to which they pertain are indistinguishable. The two concepts circulate from office to office in the form of plans, memos, discussions, scale models, and occasional synopses. In this stage of signs, language, and text, people influence the object. But once the project is realized and the object real, it is people, outside their offices, who are influenced by it—a Copernican revolution. The gulf between the world of symbols and the world of things is then apparent. The R-312 is no longer a fiction that carries me away in transports of delight; it is a bus that transports me along the Boulevard Saint-Michel.

Still, the creators of technology do not rigidly differentiate symbol from thing, project from object, the novel that excites speculation from the reality inscribed in the nature of things. For as the R-312 passes progressively from fiction to fact, its engineers repeatedly pass between the speculative and the practical realms. The capacity to be liberated from an exclusive concern from reality and to soar into unrealized potential is the quality that gives technological fiction a beauty that the literary novel, a form inherited from the naturalistic nineteenth century, has difficulty in approaching. Only a fiction that is capable of gaining or losing reality can do justice to engineers, those great unhonored figures of culture and history. A fiction with a variable structure—it is this flexibility to which we must aspire in tracking a technological project.

Question 4

According to social psychologists, people tend to respond to words and symbols as if they were the things to which they refer. What would the passage author be most likely to say about this tendency?

A. It must be repeatedly overcome by engineers as a project progresses towards its physical realization.

B. It accords with the distinction between the hypotheses of scientists and the proposals of engineers.

C. It explains the failure to honor great engineers who have turned projects into objects.

D. It implies an overemphasis on plans and working models in technological projects.

Question 4

Based on the passage, the microbiome of CD-affected individuals will result in which physiological change?

A. Increased polypeptide digestion

B. Slower dietary fiber absorption

C. Increased amount of propionate

D. Decreased immune tolerance

Using both structural and ecological perspectives, researchers examined childbearing among African American adolescents in metropolitan areas of the U.S.

The structural perspective focuses on how living in low socioeconomic status (SES) neighborhoods can affect the risk of adolescent childbearing. This perspective is divided into two explanations. Structural explanation 1 posits that the shift of industrial production away from urban centers led to an outmigration of middle-class African American families and a subsequent concentration of poverty in some African American neighborhoods. Structural explanation 2 posits that residential segregation in urban areas concentrates poverty and contributes to neighborhood decline.

The ecological perspective suggests that a neighborhood’s impact on childbearing is mediated by characteristics and changes in families. The ecological perspective includes a potentiator model, which refers to correspondence between risks from the environment and those from the family, as well as a protective model, which describes how more affluent families tend to protect their adolescents from risks in the environment.

Data were obtained from the Panel Study of Income Dynamics and were based on a sample of 940 African American females born between 1953 and 1968. By age 20, 37.7% of these females experienced a premarital birth (6.6% by age 16 and 22.8% by age 18). SES was derived from Census data and measured at age 14.

Results indicated that living in a highly segregated neighborhood was associated with an elevated rate of premarital births, regardless of neighborhood SES. In addition, adolescents who lived in low-SES households, lived with one parent, had multiple siblings, or moved frequently experienced higher rates of a premarital first birth before age 20 as compared to those who did not experience these same conditions.

Question 4

Due to the assertion that the local environment influences adolescents'' norms and values, the ecological perspective is most similar to which sociological theory?

A. Social strain theory

B. Disengagement theory

C. Differential association theory

D. Labeling theory