MutationMutationChanging your Changing your genesgenes
Mutation definedMutation defined A A MutationMutation occurs occurs
when when a DNA genea DNA gene is is damageddamaged or or changedchanged in such a in such a way as to way as to alteralter the the genetic messagegenetic message carried by that gene. carried by that gene.
Example to right the enzyme that is Example to right the enzyme that is catalyzing the production of flower catalyzing the production of flower color pigment has been altered in color pigment has been altered in such a way it no longer catalyzes such a way it no longer catalyzes the production of the red pigment. the production of the red pigment.
Types of MutationTypes of Mutation
Gene mutationGene mutation
Chromosome Chromosome mutationmutation
Gene MutationGene Mutation Gene mutation Gene mutation
– most commonmost common– within a genewithin a gene– one or more points changedone or more points changed– Base(s) can beBase(s) can be
SubstitutedSubstituted DeletedDeleted AddedAdded
– ResultResult: : proteinprotein with with 11 or or more errorsmore errors
Gene Mutation an AnalogyGene Mutation an Analogy A sentence with three letter words, A sentence with three letter words,
like the triplet codes in DNA.like the triplet codes in DNA.– ““The fat cat ate the ratThe fat cat ate the rat” makes sense” makes sense
Gene mutation Gene mutation substitutionsubstitution– Substitute an ‘Substitute an ‘aa’ for an ‘’ for an ‘oo’.’.
– ““The fat cThe fat coot ate the ratt ate the rat” nonsense, but ” nonsense, but only one word affectedonly one word affected
– ResultResult: : ProteinProtein maymay still be able to still be able to functionfunction
Gene Mutation an Analogy Gene Mutation an Analogy continuedcontinued
– ““The fat cat ate the ratThe fat cat ate the rat” makes sense” makes sense Gene mutation Gene mutation deletiondeletion
– Remove the first ‘Remove the first ‘aa’.’.– ““The The ftc ata tet her atftc ata tet her at” nonsense, and ” nonsense, and
many words affected.many words affected.– ResultResult: : ProteinProtein mostmost likelylikely will will notnot
functionfunction
How would an How would an addition/insertionaddition/insertion affect the affect the resulting amino acids?resulting amino acids?
Chromosomal MutationsChromosomal Mutations Change in Change in
structurestructure of an of an entire chromosomeentire chromosome
oror
Change in Change in chromosome chromosome numbernumber
Chromosomal MutationsChromosomal Mutations continuedcontinued
Changes in Changes in chromosomal structurechromosomal structure – A chromosome can become tangled A chromosome can become tangled
during cell division thus rearranging the during cell division thus rearranging the segmentssegments
– Five possibilities can happenFive possibilities can happen TranslocationTranslocation InversionInversion DeletionDeletion DuplicationDuplication AdditionAddition
Chromosomal structureChromosomal structure
TranslocationTranslocation– SegmentSegment of one of one
chromosome is chromosome is transferredtransferred to to anotheranother
Chromosomal structureChromosomal structure
InversionInversion– SegmentSegment is is rotatedrotated
so the so the orderorder of the of the genesgenes is is reversedreversed
Chromosomal structureChromosomal structure
DeletionDeletion– A A segmentsegment breaks breaks
offoff so so genesgenes are are lostlost
Chromosomal structureChromosomal structure
DuplicationDuplication– A A batchbatch of of genesgenes
are are duplicatedduplicated so so now have now have doubledouble of of these these genesgenes
Chromosomal structureChromosomal structure
AdditionAddition– RepetitionRepetition of of genesgenes on a on a homologuehomologue
Chromosomal MutationsChromosomal Mutations continuedcontinued
Change in Change in chromosomechromosome numbernumber– Two typesTwo types
PolyploidyPolyploidy NondisjunctionNondisjunction
Chromosome Chromosome numbernumber PolyploidyPolyploidy
– Mostly in plantsMostly in plants– Multiples of ‘n’Multiples of ‘n’
(3n, 4n, 5n)(3n, 4n, 5n)– ImproperImproper
separationseparation during during meiosismeiosis
– Often yields larger Often yields larger fruitfruit
Chromosome Chromosome numbernumber NondisjunctionNondisjunction
– MisplacementMisplacement of a of a whole chromosomewhole chromosome during during meiosismeiosis
– ResultsResults TrisomyTrisomy or or 2n +12n +1
ex: Down’s Syndromeex: Down’s Syndrome
MonosomyMonosomy or or 2n -12n -1ex: Turner’s ex: Turner’s SyndromeSyndrome