Final answer:
Hemophilia is the disease that causes defects in platelet adhesion due to a deficiency in clotting factors, resulting in the inability to form proper blood clots and an increased risk of bleeding.
Step-by-step explanation:
The disease that results in defects in platelet adhesion is hemophilia, which is a hereditary disorder that affects the body's ability to control blood clotting. People with hemophilia have a deficiency in clotting factors, which are proteins that play an essential role in blood clotting. Without sufficient levels of these clotting factors, platelets cannot adequately adhere to one another and to the walls of blood vessels, leading to an inability to form proper clots and an increased risk of excessive bleeding, even from minor injuries.