1. Friedrich Miescher first isolated nucleic acid from cell nuclei in 1869, naming it "nuclein" due to its acidic properties. 2. There are two main types of nucleic acid: DNA and RNA. DNA is found in the nucleus and mitochondria/chloroplasts, while RNA is found throughout the cell. 3. DNA provides circumstantial evidence for its role as the genetic material, as its amount is constant in somatic cells and halves in gametes, and its absorption of UV light corresponds to mutagenic effects.