Mutations

Mutations are random, rare changes in genetic material that can occur during DNA replication If a mutation occurs in part of DNA that codes for a gene, there could be a change in the characteristics of that organism Mutations can also occur in whole Chromosomes Mutations

Mutations that occur in somatic cells are NOT passed to offspring Mutations that occur in gametes (sperm and eggs) ARE passed to offspring Spiderman experienced what type of mutation?

Chromosome Mutations 5 Types of Chromosome Mutations Deletion Inversion Translocation Nondisjunction Duplication Chromosome Mutations

Due to breakage A piece of a chromosome is lost Deletion

Inversion Chromosome segment breaks off Segment flips around backwards Segment reattaches Inversion

Occurs when a gene sequence is repeated Duplication

Translocation Involves two chromosomes that are NOT homologous Part of one chromosome is transferred to another chromosome Translocation

Nondisjunction Failure of chromosomes to separate during Meiosis Causes gamete to have too many or too few chromosomes Nondisjunction

Chromosome Mutation Animation

Gene Mutations Change in the nucleotide sequence of a gene May only involve a single nucleotide Point mutation May be due to replication errors, chemicals, viruses, radioactive spiders, etc. Gene Mutations

Point Mutations Change of a single nucleotide Includes the deletion, insertion, or substitution of ONE nucleotide in a gene Sickle Cell Disease is the result of one nucleotide Substitution that changed one amino acid Occurs in the Hemoglobin gene Point Mutations

Types of Gene Mutations Substitution- one base pair is exchanged for another Can cause a change in a codon, which DOES NOT result in a change in the amino acid coded for by that codon This type of mutation is called a Silent Mutation because there is no change in the type of protein that is produced Types of Gene Mutations

Frameshift Mutation Inserting or Deleting one or more nucleotides Changes the “reading frame” of the gene Proteins built incorrectly Original: The fat cat ate the wee rat. Frame Shift (“a” added): The fat caa tet hew eer at. Frameshift Mutation

Types of Gene Mutations Insertion- an extra base pair is inserted into a new place in the DNA Types of Gene Mutations

Deletion- a base pair or section of DNA is lost or deleted 3 Types of Mutations

Amino Acid Sequence Changed

Gene Mutation Animation

A Mutagenic Factor- anything that can cause a change in DNA X-Rays and UV rays (high energy radiation) can cause breaks in DNA that are not easily repaired Chemicals can cause substitutions and changes in DNA that affect the order of amino acids in a polypeptide Substances that cause changes in DNA leading to cancer are called carcinogens Mutagenic Factors