2 Mutations Occur 1 of 2 ways 1. DNA damage from environmental agents such as UV light (sunshine)2. Mistakes when copying DNA
3 DNA Damage from Environmental agents EXAMPLESSkin Cells with sun exposureLung cells with cigarette smokeRadiationCells have the ability to repair damages, but as an organism ages, DNA repair does not work as effectively; thus changes occur in the DNA
6 Mutation: modifying nucleotide base When DNA strands are separated and copied, the altered base will pair with an incorrect base and cause a MUTATION!Environmental factors
7 G now pairs with T, instead of forming a normal pair with ___.
8 Mutation: breaking phosphate backbone TRANSLOCATION Breaking the phosphate backbone of DNA within a gene creates a mutated form of the gene.Caused by environmental agents such as nuclear radiation which can break the bonds between oxygens and phosphate groupsAnswer: It is possible that the mutated gene will produce a protein that functions differently
9 What might happen if the phosphate backbone is broken?
10 Mistakes created during DNA duplication: Mutations occur when DNA polymerase makes a mistake.ODDS1 in 100,000,000 basesDNA repair proteins fix many of these mistakes
11 What kind of mutations are there? Point mutationFrame-shift mutationDeletionInsertionInversionDNA expression mutation
12 Point Mutations A simple change in one base of the gene sequence. Original: The fat cat ate the wee rat.Point mutation: The fat hat ate the wee rat.Changed the ‘c’ in cat to a ‘h’
13 Frame Shift MutationOne or more bases are inserted or deleted but keeps the original spacing.Original: The fat cat ate the wee rat.Frame Shift: The fat caa tet hew eer at.The ‘t’ from cat was removed, but kept the original letter spacing.
14 Deletion Mutations that occur when DNA is missing. Original: The fat cat ate the wee rat.Deletion: The fat ate the wee rat.Deletion of the word ‘cat’
15 InsertionMutations that occur when extra DNA is added to the strand, insertions can also cause frame shift mutations.Original: The fat cat ate the wee rat.Insertion: The fat cat cat ate the wee rat.Extra ‘cat’ added to the sequence
16 Inversion An entire section of DNA is reversed. Original: The fat cat ate the wee rat.Inversion: The fat tar eew eht eta tac.cat ate the wee rat is invertedtar eew eht eta tac
17 American botanist Barbara McClintock won the Nobel Prize for discovering that corn genes were moving from one location to another in the chromosome.Jumping genes
18 Studies of prematurely old mice hint that DNA mutations underlie aging