This is the most focused topic in the list, and in general a narrow focus yields the strongest papers. Topic 5 takes a whole secretory response as its subject. This can be of more interest than the narrower topics, but requires considerable skill to carry it off. I m confident you will have better ones. Ideally you should have some deep curiosity about the topic you pick.
Shorter papers are usually better .
Use figures as necessary. Use section headings liberally, and keep paragraphs short. Scientific writing is dense, and needs leavening. Use any reference style you like, but please include full titles to all referenced articles. You are encouraged to use PubMed and an automatic reference database and bibliography maker such as EndNote .