Final answer:
Cancer stem cells are crucial for the development of cancer as they give rise to genetically unstable cell lineages that can undergo further mutations, contributing to the heterogeneity and complexity of the tumor. They are also resistant to chemotherapy, making them a difficult barrier in cancer treatment. Mutations in these cells lead to the loss of normal cell cycle control, which can provoke uncontrolled cell division and metastasis.
Step-by-step explanation:
The role of a cancer stem cell in cancer development is that it gives rise to multiple lineages of genetically unstable cells that can each undergo additional mutation. Cancer stem cells contribute to the complexity and persistence of cancers. These cells are capable of self-renewal and can differentiate into a variety of cell types that constitute the tumor. Additionally, cancer stem cells are notoriously resistant to chemotherapy, making them a key target in developing more effective cancer treatments.
Mutations in these stem cells, whether they occur in somatic or germ cells, can lead to cancerous growth if they result in the loss of normal cell cycle control mechanisms. Unlike mutations in germ cells, which are hereditary, somatic mutations affect only the descendant cells of the mutated cell and can be the direct cause of cancer. The accumulation of such mutations can result in a homeostatic imbalance that leads to uncontrolled cell division and the formation of tumors. Moreover, these tumors have the potential to metastasize, spreading the cancer to other parts of the body.