Vitamin D is unique in that it can be obtained by the diet but also is synthesized inside the body when a cholesterol-like substance is activated by sunlight and converted to the prohormone vitamin D. What are the organs participate in vitamin D synthesis as a result of sunlight exposure

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.