The primary function of the proximal convoluted tubule is?
a) secretion of acids and ammonia
b) filtration
c) adjusting urine volume
d) secretion of drugs
e) re-absorption of ions, organic molecules, vitamins, and water

Ras is a g-protein that is activated when a growth factor attaches to egfr. its activation results in the replacement of a gdp molecule with a gtp molecule, thus allowing a signal transduction pathway to be activated. considering the signal pathway illustrated on this page, what is one potential outcome of a mutation in the ras gene that leads to ras protein hyperactivity. be specific.