Mutations

Mutations Mutation Germ Cell Mutations Somatic-Cell Mutations Change in the nucleotide base sequence of a gene or DNA Germ Cell Mutations Mutation in an organism’s sex cells or gametes Will not affect that organism…but can affect the offspring Somatic-Cell Mutations Take place in an organism’s body cells Can affect organism (certain types of cancer) Cannot be inherited

Mutations… Lethal Mutations Beneficial Mutations Cause death, often before birth of an organism Beneficial Mutations Organisms will have a better chance of survival, and thus an evolutionary advantage.

Chromosome Mutations Deletion Inversion Translocation Nondisjunction Loss of a piece of a chromosome due to breakage Inversion Piece of chromosome breaks off, but reattaches backwards Translocation Piece of chromosome breaks off and reattaches to a non homologous chromosome Nondisjunction Chromosome fails to separate from its homologous pair during Meiosis 1

Chromosome Map

Chromosome Mutations

Nondisjunction results in Down Syndrome http://www.friendshipcircle.org/blog/2012/05/22/13-chromosomal-disorders-youve-never-heard-of/

Gene Mutations Point Mutation- Switching, adding, or removing a single nucleotide (letter of DNA) Substitution- 1 letter replaces another, 1 amino acid is affected Missense- 1 Amino Acid Switched Nonsense- Changes Amino Acid to a “Stop” Silent- Amino Acid is the same…no change Frameshift- Insertion or Deletion of 1 nucleotide affects all Amino Acids down the line…

Gene Mutations

http://highered. mcgraw- hill http://highered.mcgraw- hill.com/sites/0072556781/student_view0/c hapter11/animation_quiz_4.html https://www.youtube.com/watch?v=eDbK0cx KKsk