V. DNA vs. RNA DNA o Deoxyribose sugar o Thymine o Double helix o Housed in the nucleus o Longer (many genes) o 1 type RNA o o o o o o Ribose sugar Uracil Single-stranded Can go in and out of the nucleus Shorter (1 gene length) Different types – mRNA, tRNA Are all mutations bad? I. Gene Mutations: a random change in the nucleotide sequence of DNA that occurs within a gene II. Types: a. Frame shift mutation: gene mutation that shifts the “reading” frame of genetic message by inserting or deleting a nucleotide b. Point mutation: gene mutation that affects a single nucleotide usually by substituting one nucleotide for another. III. Causes: Inherited, environmental, random. IV. Effect of gene mutations: a. Mutations can cause a change in the proteins a cell synthesizes. b. Mutations can be harmful, beneficial, or have no effect at all.