Mutations 10 th Grade Biology Mr Coombs Genetic

Mutations 10 th Grade Biology Mr. Coombs

Genetic Changes • A mutation is any change to the DNA sequence. • Chromosomal mutations • Frameshift mutations • Point mutations • Only mutations in sex cells can be transmitted to offspring. • Potentially can produce new species

Chromosomal Mutations • Deletion: Part of a chromosome is left out • Insertion: Part of a chromatid breaks off and attaches to its sister chromatid • Inversion: Part of a chromosome breaks off and reattaches backwards • Translocation: Part of one chromosome breaks off and is added to a different chromosome.

Frameshift Mutations • A mutation in which a single base is added to or deleted from DNA • THE DOG BIT THE CAT • THE DOB ITT HEC AT

Point Mutations • A change in a single base pair in DNA • THE DOG BIT THE CAT • THE DOG BIT THE CAR

Causes of Mutations • Mutagens • any agent which can cause a change in DNA. • • Radiation X-rays UV light Chemicals like asbestos, benzene, formaldehyde

Are mutations bad?

Are mutations bad? • It depends • If the change causes disease • Example: cancer • If the change allows the organism to be faster, stronger, smarter? • EVOLUTION, BABY!

Examples of Mutations in Humans

Progeria • Mutation of a single gene • The gene, known as lamin A (LMNA), makes a protein necessary for holding the nucleus of a cell together. • Extremely rare • Progressive (gets worse as the individual ages) • Causes rapid aging

Sickle Cell Anemia • Caused by a single amino acid mutation (point mutation) in the protein hemoglobin. • Hemoglobin allows red blood cells to carry oxygen from your lungs to all parts of your body. • Red blood cells to become rigid, sticky and mis-shapen. • Benefit: carriers of the sickle cell gene have some resistance to malaria.

CCR 5 -Delta 32 • Beneficial mutation • Causes HIV resistance • A deletion causes a frameshift mutation which changes the order of amino acids

Tetrachromacy • Allows for widened color vision • Thought to be caused by a mutation on the X chromosome • Artist Concetta Antico

Questions 1. Any change in the genetic code is called? 2. A chromosomal mutation in which part of a chromosome is added to a different chromosome. Example: Part of chromosome 1 breaks off and is added to chromosome 14. This mutation is called? 3. A mutation which changes a single nucleotide in a DNA strand is called? 4. A chromosomal mutation in which part of a chromosome breaks off and then rejoins incorrectly is called? 5. When part of the chromosome/DNA is left out is called what type of mutation?