Final answer:
Oncogenes are mutated versions of proto-oncogenes that improperly enhance the expression of genes that promote cell proliferation or inhibit apoptosis. Proto-oncogenes are normal genes that help cells divide. When a proto-oncogene mutates to become an oncogene, it becomes continuously active, leading to uncontrolled cell division and potentially causing cancer.
Step-by-step explanation:
Oncogenes are mutated versions of proto-oncogenes that improperly enhance the expression of genes that promote cell proliferation or inhibit apoptosis. Proto-oncogenes are normal genes that code for positive cell-cycle regulators and help cells divide. When a proto-oncogene mutates to become an oncogene, it becomes continuously active, leading to uncontrolled cell division and potentially causing cancer.