Final answer:
The author of The Immortal Life of Henrietta Lacks, Rebecca Skloot, effectively uses elements of informational text to establish her purpose.
Step-by-step explanation:
The author of The Immortal Life of Henrietta Lacks, Rebecca Skloot, uses elements of informational text, such as a thesis, evidence, examples, and a conclusion, to help the reader understand the purpose of the book. Skloot establishes her purpose through a clear thesis statement, which is the main idea or argument of the book. She supports her purpose by providing extensive evidence and examples from her decade of research. Finally, Skloot concludes the passage with a summary of the purpose, helping to reinforce the main message of the book.