Final answer:
A 'vicious cycle' in biology typically refers to cascading problems that amplify initial imbalances, such as increased prey leading to more predators, which then decrease prey numbers, and so on. In medicine, it can refer to the uncontrollable division of cells in cancer if regulatory mechanisms of the cell cycle fail. Such cycles must be interrupted to prevent ongoing negative consequences.
Step-by-step explanation:
When discussing a 'vicious cycle' in a biological context, it often refers to a situation where imbalance in one part of an ecosystem or biological process leads to further imbalances and exacerbates the original problem if not interrupted. For example, in predator-prey dynamics, if prey increase in numbers, this can cause a subsequent increase in the predator population. However, as predators thrive, they may reduce the prey population to a point where it causes a downturn in predator numbers due to the lack of food. This could then allow prey populations to increase again, starting the cycle anew. Circular flow diagrams in economics can demonstrate similar phenomena, where one part of an economy slows down and negatively impacts other parts, creating a stalled growth scenario.
In medicine, when discussing the cell cycle out of control, such as in cancer, the failure to regulate cell division can cause malignant cells to multiply unchecked, leading to tissue damage and potential death. Essential mechanisms usually regulate the cell cycle, but environmental factors or genetic abnormalities can activate oncogenes or deactivate tumor-suppressor genes, leading to cancer. If these negative feedback systems fail to interrupt the cycle, it may result in a continuous division of abnormal cells and the progression of cancer.