DNA and Mutations DNA Molecule Makeup Human DNA

DNA and Mutations

DNA Molecule Make-up • Human DNA consists of 3 billion base pairs • The bases of A, T, G, and C form the alphabet of the genetic code. • Groups of the three bases codes a specific amino acid.

Examples § CCA code for the amino acid Proline. § AGC code for the amino acid Serine.

Genes and Proteins § The order of the bases determines the order of the amino acids in a protein. § Each gene is a set of instructions for making a protein.

When things go wrong… § A mutation is when there is a change in the order of the bases in an organism’s DNA. § Deletion- when a base is deleted § Insertion- when a base is added § Substitution- When a base is switched

Examples ACTCCTGAAGAAAAA TGAGGACTTCTTTTT ACTCCTGTAGAAAAA TGAGGACATCTTTTT

Mutagens § Anything that can cause a mutation in DNA. § Mostly by physical or chemical agents.

Other examples § § § Asbestos Chemicals in cigarette smoke pollution

So are they always bad? ? § Mutations can hurt, help, or have no effect on organisms. § § § Diseases like sickle cell anemia Evidence of evolution in organisms No change in organism

Mutations Sickle cell anemia

Mutations Sickle Cell Anemia

Mutations Sickle cell anemia

Mutations Good mutations. Genetically engineered food

Bad mutations Antibiotic resistant bacteria (bad for us!!!!)

Neither good not bad Eye color

Or…. Depending on where you live, mutations can be good or bad… Sickle Cell Anemia

Malaria

Sickle Cell Anemia

Inheritance: § Half-shaded – carrier § Fully shaded – has it § Not shaded at all – does not have it