1) In a well constructed paragraph explain & describe the biases in this Case-Control study?

Case-Control study: A researcher plans to investigate the efficacy of a new pancreatic cancer screening tool, using a Case-Control study design. She selects patients from 10 physicians' offices, and places them into two groups. The Control group has no family history of pancreatic cancer. They receive one screening per year using the typical method. The Case group has a family history of pancreatic cancer. They receive two screenings per year, using the new technique.