Final answer:
To signal a shift in focus in a paragraph, Sentence 5 would be the optimal starting point for a new paragraph when transitioning from discussing fireflies' habitats to their life cycle. This method enhances organization and reader comprehension by clearly dividing distinct subtopics.
Step-by-step explanation:
To effectively divide the paragraph to signal a shift from discussing fireflies' habitats to their life cycle, one should start the new paragraph at the beginning of Sentence 5. This sentence likely introduces the topic of the life cycle after discussing habitats in the previous sentences. In academic and expository writing, transitions are critical for guiding the reader through the argument or discussion, which is why the introduction of a new subtopic, such as life cycles after habitats, justifies the start of a new paragraph. The separation helps to organize the paper effectively, using transitional words or phrases to demonstrate the relationship between the ideas. Moreover, this clear division enhances the reader's understanding by compartmentalizing different aspects of the subject matter.
When drafting paragraphs that explain cause-and-effect relationships, starting a paragraph with either the cause or the effect can signal to the reader what to expect in the following sentences. Since life cycles can be viewed as an effect or outcome of the insect's adaptation to its habitat, this indicates a shift in focus and is a fitting point for a new paragraph, ensuring the paper's organization aligns well with the ways transition can guide the reader's comprehension.