Final answer:
Cancer cells differ from normal cells by their ability to divide uncontrollably due to a lack of regulation in their cell cycle, leading to the potential development of tumors.
Step-by-step explanation:
Cancer cells differ from normal cells in several key ways, particularly in their ability to divide uncontrollably. Normal cells undergo a regulated cell cycle and typically stop dividing when they come into contact with neighboring cells, a process known as contact inhibition. In contrast, cancer cells bypass these regulatory mechanisms due to DNA damage, often caused by carcinogens such as radiation or chemicals. As a result, they do not undergo apoptosis, the programmed cell death which is a natural defense to prevent the propagation of damaged cells. Instead of stopping growth at confluence, cancer cells continue to grow and divide, leading to the formation of abnormal masses of cells, known as tumors.
Cancer treatment often involves targeting the unregulated division of these cells. It's noteworthy that while some sources may point to fewer mitochondria as a characteristic of cancer cells, a key distinguishing feature of cancer cells is indeed their continuous, unregulated division, which the student's question addresses.