DNA Mutations Section 11.3

Review DNA controls structure and function of cells because it holds the code to build all proteins. DNA transcription translation mRNA Amino acid sequence

Mutation—mistakes in the DNA Mistakes can occur randomly through errors in replication, transcription, or cell division. External factors can also cause mutations.

Mutations can occur in reproductive cells (sperm or egg) or in body cells. Only adult cells affected Only offspring affected New protein that is better than before New protein hurts organism or doesn’t work at all. Mutation in body cell Mutation in sperm or egg Cell may no longer work properly Cell doesn’t reproduce properly  may lead to cancer

Certain types of mutations are found in the genes or DNA Point mutation is the change in a single base pair. –EX. When you change one letter in a sentence: THE DOG BIT THE CAT. THE DOG BIT THE CAR.

DNA mutations con’t Frameshift mutation is when one base is deleted or inserted and the whole sequence shifts. –EX: If you delete the letter G, from the original sentence: THE DOG BIT THE CAT. THE DOB ITT HEC AT. –EX: If you insert the letter A, into the sequence. THE DOG ABI TTH ECA T.

Chromosomes carry large amounts of genetic material and can also have mutations

Mutation causes are called mutagens. Radiation (nuclear, x-ray, UV, etc), asbestos, formaldehyde all can lead to mutations. Organisms have evolved several enzymes that check and repair DNA, but the more exposure to a substance, the more chances for mistakes.