Final answer:
The central idea of a paragraph is expressed in the topic sentence, which is supported by details and evidence throughout the paragraph. Each topic sentence should be aligned with the essay's thesis. Effective paragraph development, including a strong topic sentence, is imperative for supporting the essay's main ideas and for cohesive writing.
Step-by-step explanation:
The central idea of a paragraph is primarily conveyed through its topic sentence, which is usually positioned at or near the beginning of the paragraph. This sentence sets the stage for the details, examples, quotations, paraphrases, and summaries that follow, serving to support and develop the point made in the topic sentence. Each topic sentence should relate to the overall thesis of the essay, helping to create a cohesive argument that progresses logically from one point to the next.
In providing feedback, peer review often emphasizes the need for a strong topic sentence and the importance of development in the paragraph. An underdeveloped paragraph containing only one sentence, for instance, lacks the necessary depth and fails to effectively support the main ideas of the essay. The effective use of topic sentences and development of ideas with evidence is also crucial in ensuring the paragraph contributes to the overall purpose of the paper.