There have long been dead zones—water too low in oxygen to sustain most forms of life—in the Gulf of Mexico, which receives the waters of the Mississippi River. Scientists studied sediment cores from areas where the gulf’s most recent dead zone occurred. The scientists dated the sediment and counted species of foraminifera (marine protozoans) in the sediment; these species thrive in low-oxygen waters. As far back as 1823, the foraminifera thrived especially during Mississippi River flood years (during which nutrients levels increase), suggesting that nutrients in floodwaters can trigger low-oxygen water. The foraminifera in the core samples were most abundant after 1950, when farmers began using some fertilizer, which is rich in nutrients. Researchers believe that increased use of fertilizer leads to more-extreme dead zones.
1. Which of the following best describes the function of the highlighted sentence in the context of the passage as a whole?
A. It reconciles two opposing theories that were discussed earlier in the passage.
B. It suggests what the initial impetus was for the studies mentioned earlier in the passage.
C. It undermines a hypothesis that was presented in the preceding sentence.
D. It describes a problem with the methodology of the studies discussed in the passage.
E. It provides evidence supporting the belief mentioned in the final sentence of the passage.
2. It can be inferred from the passage that the “researchers” would agree with which of the following statements about the use of fertilizer? (Consider each of the choices separately and select all that apply.)
A. If farmers near the Mississippi River decreased the amount of fertilizer that they used, the severity of the dead zones could be diminished.
B. If farmers near the Mississippi River continue their dependence upon fertilizers, foraminifera population will eventually decline.
C. If farmers near the Mississippi River stopped using fertilizers altogether, there would no longer be dead zones.
Because different mammalian species are dependent on plants for organic matter. Plants provide organic matter for soil communities through the decomposition of leaf litter, by oozing nutrients from roots, or through other methods of deposition of organic compounds into the soil environment. As a result of these diverse methods by which plants supply resources, unique soil communities form under different plant species and under plant communities that differ in composition. If a nonnative plant species invades an aboveground community of flora and fauna, it can alter links between the native aboveground community and the belowground soil community. For example, an invading nonnative plant could alter the quantity of leaf litter production, which would alter nutrient contributions to the soil.
1. According to the passage, plants supply resources to soil communities by which of the following methods?
A. Some plants supply resources to soil communities by promoting diversity of aboveground flora and fauna.
B. Some plants supply resources to soil communities by oozing nutrients from their roots.
C. Some plants supply resources to soil communities by depositing leaf litter.
2. Which of the following statements about the connection between aboveground plants and belowground soil communities can be inferred from the passage?
A. Because of the nature of the link between above-and belowground communities, many soil communities are deficient in nutrients.
B. The extent to which soil communities are dependent on aboveground plants is extremely variable from one soil community to another.
C. Because different plants supply resources to soil communities in different ways, distinctive soil communities form under different plant communities.
Architectural morphology is the study of how shifting cultural and environmental conditions produce changes in an architectural form. When applied to the mission churches of New Mexico exemplifying seventeenth- and eighteenth-century Spanish colonial architecture in what is now the southwestern United States, architectural morphology reveals much about how Native American culture transformed the traditional European church architecture of the Spanish missionaries who hoped to convert Native Americans to Christianity.
Many studies of these mission churches have carefully documented the history and design of their unique architectural form, most attribute the churches’ radical departure from their sixteenth-century European predecessors to local climate and a less-mechanized building technology. Certainly, the limitations imposed by manual labor and the locally available materials of mud-brick and timber necessitated a divergence from the original European church model. However, the emergence of a church form suited to life in the Southwest was rooted in something more fundamental than material and technique. The new architecture resulted from cultural forces in both the Spanish colonial and indigenous Native American societies, each with competing ideas about form and space and different ways of conveying these ideas symbolically.
For example, the mission churches share certain spatial qualities with the indigenous kiva, around, partly subterranean room used by many Southwest Native American communities for important rituals. Like the kiva it was intended to replace, the typical mission church had thick walls of adobe (sun-dried earth and straw), a beaten-earth floor, and one or two small windows. In deference to European custom, the ceilings of these churches were higher than those of the traditional kiva. However, with the limited lighting afforded by their few small windows, these churches still suggest the kiva's characteristically low, boxlike, earth-hugging interior. Thus, although pragmatic factors of construction may have contributed to the shape of the mission churches, as earlier studies suggest, the provision of a sacred space consistent with indigenous traditions may also have been an important consideration in their design.
The continued viability of the kiva itself in Spanish mission settlements has also been underestimated by historians. Freestanding kivas discovered in the ruins of European-style missionary communities have been explained by some historians as examples of “superposition”. Under this theory, Christian domination over indigenous faiths is dramatized by surrounding the kiva with Christian buildings. However, as James Ivey points out, such superposition was unlikely, since historical records indicate that most Spanish missionaries, arriving in the Southwest with little or no military support, wisely adopted a somewhat conciliatory attitude toward the use of the kiva at least initially. This fact, and the careful, solitary placement of the kiva in the center of the mission-complex courtyards, suggests an intention to highlight the importance of the kiva rather than to diminish it.
Sport fishers introduced the Zander, a type of perch, to Britain’s rivers and canals in the 1970s. Because zander eat large numbers of smaller fish, they have had a devastating effect on native fish populations. To protect the native fish, a government program removed a significant proportion of the zander from Britain’s waterways last year. Surprisingly, this year the loss of native fish to zander has been greater than before.
Which of the following, if true, would most help to explain the greater effect of zander on the native fish population?
A. The climate in Britain is very similar to the climate in regions to which zander are native.
B. Most of the zander removed were fully grown, and fully grown zander eat large numbers of smaller zander.
C. Every year a large number of zander are caught by sport fisher in Britain’s waterway.
D. Previous government program designed to remove nonnative species from Britain’s waterways have failed.
E. Zander are just one of several nonnative fish that prey on the other fish found in Britain’s waterway.