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Larvae of many marine invertebrate species delay their metamorphosis into juveniles when cues signaling an appropriate juvenile environment are absent, thereby increasing their likelihood of thriving as juveniles and of ultimately reaching adulthood. Nevertheless, delayed metamorphosis has potential costs for juveniles, including reduced growth and increased mortality. Nearly all evidence of such costs involves species whose larvae do not feed but rather subsist on stored nutrients, indicating that insufficient energy reserves may be an underlying cause of these costs. Supporting this hypothesis are laboratory studies showing that in a certain bryozoan, the prolonged larval swimming that results from delayed metamorphosis is associated with size reductions in the juvenile feeding organ(the lophophore) and that one factor influencing the size of juveniles of certain barnacle species is how long larvae delay metamorphosis. However, other studies show that while significantly fewer juvenile Capitella worms survived to adulthood when metamorphosis had been delayed, prolonged larval swimming had no significant effect on juvenile size, suggesting, perhaps, that in some species, factors other than insufficient energy reserves account for the negative effects of the larval stresses that result from delayed metamorphosis.
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The passage is primarily concerned with
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According to the passage, larvae of many marine invertebrate species delay their metamorphosis into juveniles when the larvae
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The "hypothesis" implies that compared to marine invertebrate larvae that subsist on stored nutrients, marine invertebrate larvae that feed are less likely to
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The phonograph never merely recorded music: it changed both how people listened and how they played. Early recordings of violinists suggest that vibrato--the trembling action of hand or fingerboard that gives notes a warbling sweetness-was once used more sparingly than it is today. By the 1930s, many leading violinists had adopted continuous vibrato, which became the approved style taught in conservatories. Musicologist Mark Katz proposes that technology prompted the change. When vibratos wobble was added to violin tone, the phonograph could pick it up more easily; acoustically, it's a "wider" sound. Also, vibrato's fuzzier focus enabled players to cover up inaccuracies of intonation, and phonographs made players self-conscious about intonation. What worked in recording studios spread to concert stages.
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The passage implies that after phonograph technology became widespread, which of the following occurred?
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Until the early 1900s, there was little discussion by art critics of still-life painting in the United States. While portraiture and landscape painting were discussed in terms not only of their leading practitioners but of their implications and relative merits, still life, when mentioned at all, was usually denigrated as a theme unworthy of serious consideration by either critic or artist. Among the objections raised against still life were that it represented "low subjects, " inanimate objects such as fruits and flowers, and that artists choosing the genre aspired only to exactness of imitation.
Since 1900, however, new value has been placed on personal expression and artistic execution, regardless of subject matter, and critics have come to recognize the individuality that an artist brings to a rendering of the various subjects of the still life. Today critics see that still life may evoke a mood or reflect cultural or economic conditions.
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Information in the passage suggests that critics before 1900 were less interested than are present-day critics in which of the following?
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The passage mentions which of the following as an objection to still-life painting raised by critics before 1900?
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It can be inferred from the passage that before 1900 critics' discussions of still-life painting would have been LEAST likely to include which of the following?
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According to data collected in England in the early nineteenth century, children working in coal mines were much shorter than other children of the same ages. Since the coal mines had many tight spaces, a frequent explanation has been that mine managers would have avoided employing tall children. Some scholars have rejected this explanation, pointing out that since exposure to sunlight is necessary for the body`s production of a growth hormone, deprivation of sunlight probably caused child miners growth to be stunted. But, clearly, the true explanation is that both of these factors were at work. For one thing, they can in fact operate independently. More importantly, the differences in children's heights were so extreme that neither explanation alone would account for them satisfactorily.
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In the argument given. the two highlighted portions play which of the following roles?
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W.E. B. Du Bois's exhibit of African American history and culture at the 1900 Paris Exposition Universelle attracted the attention of a world of sociological scholarship whose values his work challenged. Du Bois believed that Spencerian sociologists failed in their attempts to gain greater understanding of human deeds because their work examined not deeds but theories and because they gathered data not to effect social progress but merely to theorize. In his exhibit, Du Bois sought to present cultural artifacts that would shift the focus of sociology from the construction of vast generalizations to the observation of particular living individual elements of society and the working contributions of individual people to a vast functioning social structure.
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The passage implies that Du Bois attributed which of the following beliefs to Spencerian sociologists?
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The passage implies that Du Bois believed which of the following statements about sociology?
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Among the scientific anachronisms in the United States Endangered Species Act is the absence of specific reference to interactions among species, which can greatly affect ecological and species diversity. It is now understood that the disappearance of a strongly interactive species can cause profound changes in ecosystem composition and structure. For instance, decimation of great whales by industrial whaling affected other species that, like the whales, consume krill(small, shrimplike crustaceans), and the dynamics of coastal marine ecosystems worldwide have been greatly altered by overfishing of certain species. Decreased numbers and reduced geographic range may render a species functionally extinct in terms of its interactions well before the species itself has completely disappeared. Nevertheless, most conservation laws emphasize short-term, single-species demographic viability in only a few circumscribed areas.
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It can be inferred that the author of the passage would agree with which of the following statements about the United States Endangered Species Act?
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The author alludes to functional extinction primarily in order to imply that
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In 1644 Descartes described Earth as consisting of a central nucleus of hot primordial fluid surrounded by a solid opaque layer and then succeeding layers of rock, metal, water, and air. Geophysicists still subscribe to the notion of a layered Earth. In the current view, however, Earth possesses a solid inner core and a molten outer core, both consisting of iron-rich alloys at enormous temperatures and pressures, followed, at about 2,900 kilometers below the surface, by a mantle of solid, less dense magnesium-iron silicates; the boundary between the upper and lower mantle lies 670 kilometers below the surface. At 30-50 kilometers below the continental surface (less than 10 kilometers below the seafloor), the Mohorovicic discontinuity marks an additional boundary--that between the mantle and the less dense crust above it.
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According to the current view, a feature that distinguishes Earth's mantle from its core is that the mantle
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