Final answer:
Ranibizumab and Bevacizumab target and inhibit the vascular endothelial growth factor (VEGF), which is responsible for promoting the growth of blood vessels. These monoclonal antibodies bind to VEGF, preventing its action and inhibiting the growth of abnormal blood vessels in various medical conditions.
Step-by-step explanation:
The target of action of Ranibizumab and Bevacizumab is the vascular endothelial growth factor (VEGF), which is a protein that promotes the growth of blood vessels. Ranibizumab and Bevacizumab are monoclonal antibodies that specifically bind to VEGF, preventing it from binding to its receptors and inhibiting the growth of abnormal blood vessels in conditions such as age-related macular degeneration and certain types of cancer.