Yeah, a fifteen-fret uke will have two octaves. The lowest note is middle C. Then the E string (open) is the E above middle C, the A (also open) is the A above middle C, then fifteen frets down you have the second C above middle C. That's two octaves.
Yes, peanuts and peanut butter can aggravate arthritis. I was a peanut butter eater all my life, I am now 58.
Peanuts actually grow underground, as opposed to nuts like walnuts, almonds, etc. that grow on trees (and are sometimes referred to as tree nuts). Peanuts, along with beans and peas, belong to the single plant family, Leguminosae. Legumes are edible seeds enclosed in pods.