Discusses the history of cloning, its possible applications, and some of the controversy surrounding it.

Describes different kinds of microorganisms, including bacteria, fungi, and algae, and both their harmful and beneficial effects, as well as efforts to prevent the harm that some germs cause.

Discusses the history of man's knowledge of the heart, early heart surgery, and the results, possible complications, costs, and future of heart transplants.

Discusses the impact of chemotherapy as a treatment for cancer, its history and development, challenges it presents, and future research.