Final answer:
The signaling pathway involving MAPK and Raf-1, responding to external signals and affecting cell proliferation and differentiation, is known as the Raf-1/MAPK pathway. This pathway is triggered by the Ras protein-mediated activation and can lead to uncontrolled cell proliferation if mutations occur.
Step-by-step explanation:
The correct option is C:
The signaling pathway that includes mitogen-activated protein kinase (MAPK) and Raf-1, playing a vital role in cellular responses to extracellular signals, is the c) Raf-1/MAPK pathway. This pathway is central to many receptor kinase signaling pathways, crucial for cellular processes such as cell proliferation and differentiation. Ras protein-mediated activation, often found in tumor cells, starts a phosphorylation cascade which triggers the MAP kinase signaling that affects gene activity leading to these processes.
When the epidermal growth factor (EGF) binds to its receptor tyrosine kinase, it initiates the MAP-kinase cascade resulting in cellular responses such as cell division. The activated MAPK pathway can also lead to abnormal cell proliferation if left unchecked, contributing to tumorigenesis. Termination of the signaling cascade through degradation and dephosphorylation is crucial for ensuring correct cellular responses.