Question

17 mark for review the epidermal growth factor receptor egfr is a cell surface receptor. when a growth factor binds to egfr, the receptor is activated. the activated egfr triggers a signal transduction pathway, which leads to increased frequency of cell division. which of the following best predicts the effect of a mutation that causes egfr to be active in the absence of a growth factor? a increased apoptosis will lead to abnormal growth of the tissue. b increased cell division will lead to the formation of a tumor. c cells will exit the cell cycle, entering a non - dividing ( g_0 ) phase d fewer cells will be in any of the stages of mitosis.

Explanation:

EGFR activation normally triggers increased cell division when a growth factor binds. A mutation making EGFR active without growth factors will continuously stimulate cell division. Uncontrolled, excessive cell division leads to tumor formation. Option A is incorrect because apoptosis (cell death) would not cause abnormal growth here. Options C and D are wrong as they describe reduced cell division, which is the opposite of the effect of constant EGFR activation.

Answer:

B. Increased cell division will lead to the formation of a tumor.