What is the source of oxygen in the epipelagic zone ?

What is the importantence of the carbon and nitretan cycles in the environment

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.

Can a trait be both polygenic and have multiple alleles? explain why or why not.