Examkin

Question

Difficulty: MediumPrimary Purpose of the Whole Text

Historically, kelp forests have been celebrated primarily for their role in supporting marine biodiversity, serving as crucial habitats for numerous fish and invertebrate species. However, recent marine ecological research has shifted focus toward their capacity for carbon sequestration. Unlike terrestrial forests, which store carbon in biomass that eventually decays and releases carbon dioxide back into the atmosphere, kelp grows rapidly and constantly sheds organic matter. A significant portion of this detritus is transported by deep ocean currents to the sea floor, where it becomes buried in marine sediments. By export-sequestering carbon in the deep ocean, kelp ecosystems act as highly efficient carbon sinks. Thus, kelp forests are increasingly recognized not just as hotspots of biodiversity, but as vital agents in mitigating global climate change.

Which choice best states the primary purpose of the text?

  1. A
    To detail the ocean currents that transport organic detritus to the sea floor.
  2. To explain how kelp forests function as carbon sinks that help mitigate climate change.Answer
  3. C
    To argue that terrestrial forests release more carbon dioxide than they absorb.
  4. D
    To advocate for the protection of all marine biodiversity hotspots from climate change.

Answer

The correct answer explains how kelp forests function as carbon sinks that help mitigate climate change.
The correct answer outlines the primary focus of the passage, which is how kelp forests sequester carbon in deep marine sediments and thereby contribute to climate change mitigation.

Step-by-Step Solution

1
Analyze the structure of the passage
The text begins by acknowledging the traditional view of kelp forests as biodiversity supporters, shifts focus to recent research on carbon sequestration, explains the process of this sequestration, and concludes that kelp forests are vital agents in climate change mitigation.
To understand how the text is organized and what ideas are emphasized.
2
Distinguish between details and the overall primary purpose
The details about kelp growth, detritus transport, and deep ocean currents are used to explain the mechanism of carbon sequestration, which supports the main point about climate change mitigation.
To avoid choosing options that focus on narrow details rather than the text as a whole.
3
Evaluate the choices to find the one that best summarizes the entire text
The explanation of kelp forests as carbon sinks that help mitigate climate change matches the overall focus of the passage, whereas other options are either too broad, factually incorrect based on the text, or focus on minor details.
To select the option that best states the primary purpose.

Key Concept

Identifying the primary purpose of the whole text by distinguishing the main thesis from supporting details and avoiding overgeneralizations.
Estimated Time:1m 30s
Rate this question

Topics

Primary Purpose of the Whole Text

More questions from this topic