Genetic MutationsGenetic Mutations

What Are Mutations?What Are Mutations?

Changes in the nucleotide sequence Changes in the nucleotide sequence of DNAof DNA

May occur in body cells and are not May occur in body cells and are not passed to offspringpassed to offspring

May occur in gametes (eggs & May occur in gametes (eggs & sperm) and be passed to offspringsperm) and be passed to offspring

Are Mutations Helpful or Are Mutations Helpful or Harmful?Harmful?

Mutations happen regularly and Mutations happen regularly and often neutral often neutral

Many mutations are naturally Many mutations are naturally repaired by enzymesrepaired by enzymes

Causes of mutations:Causes of mutations:NaturalNaturalChemicalsChemicalsRadiationRadiationOther environmental factorsOther environmental factors

Are Mutations Helpful or Are Mutations Helpful or Harmful?Harmful?

Some mutations are harmful and Some mutations are harmful and can cause:can cause:CancerCancerBirth defectsBirth defectsPhysical impairmentsPhysical impairmentsOther life altering conditionsOther life altering conditions

Some mutations may improve an Some mutations may improve an organism’s survival organism’s survival This is know as evolutionThis is know as evolution

Types of MutationsTypes of Mutations

Chromosome Mutations and Gene Chromosome Mutations and Gene MutationsMutations

Chromosome Chromosome MutationsMutations

May Involve:May Involve:Changing Changing

the the structurestructure of of a a chromosomechromosome

The The loss or loss or gaingain of part of of part of a a chromosomechromosome

Types of Chromosome Types of Chromosome MutationsMutations

Five types exist:Five types exist:DeletionDeletionInversionInversionTranslocationTranslocationNondisjunctionNondisjunctionDuplicationDuplication

DeletionDeletionDue to Due to

breakage, abreakage, a piecepiece of a chromosome is of a chromosome is

lost lost

InversionInversionChromosome segment Chromosome segment breaks offbreaks offSegment flips around Segment flips around backwardsbackwards

Segment Segment reattachesreattaches

DuplicatioDuplicationn

Occurs Occurs when a gene when a gene sequence is sequence is

repeatedrepeated

TranslocatiTranslocationon

Involves Involves two two chromosomes chromosomes

that not that not homologoushomologous

PartPart of one of one chromosome is chromosome is transferred to transferred to

anotheranother chromosomeschromosomes

NondisjunctionNondisjunction

Caused by a failure of chromosomes to Caused by a failure of chromosomes to separate during meiosisseparate during meiosisAs a result, the gamete will have too As a result, the gamete will have too

many or too few chromosomesmany or too few chromosomes

Gene MutationsGene Mutations

What are What are Gene Gene

Mutations?Mutations?Change in the Change in the

nucleotide sequence nucleotide sequence of of a genea gene

May only involve a May only involve a single nucleotidesingle nucleotide

May be due to May be due to copying copying errorserrors, , chemicalschemicals, ,

virusesviruses, etc., etc.

Types of Gene Types of Gene MutationsMutations

Include:Include:Point MutationsPoint MutationsSubstitutionsSubstitutionsInsertionsInsertionsDeletionsDeletionsFrameshiftFrameshift

Point MutationPoint Mutation

What is it?What is it?

Change of a Change of a singlesingle nucleotide nucleotide

Includes the Includes the deletion, insertion, deletion, insertion, or substitution of or substitution of ONEONE nucleotide in nucleotide in a genea gene

Example:Example:

Sickle Cell Sickle Cell disease disease is the is the result of one result of one nucleotide nucleotide substitutionsubstitution

Occurs in the Occurs in the hemoglobin hemoglobin genegene

Frameshift MutationFrameshift Mutation

Inserting or Inserting or deleting one or deleting one or more nucleotidesmore nucleotides

Changes the Changes the ““reading framereading frame”” like changing a like changing a sentencesentence

Causes proteins to Causes proteins to be built incorrectlybe built incorrectly

Food incFood incClass DiscussionClass Discussion

DiscussionDiscussion

See teacher for detailsSee teacher for details

Modern GeneticsModern Genetics

ObjectivesObjectives

Describe ways of producing organisms with Describe ways of producing organisms with desired traitsdesired traits

State the goal of the human genome projectState the goal of the human genome project

Selective Breeding Selective Breeding

Definition: The process of selecting organisms Definition: The process of selecting organisms with desired traits to be the parents of the with desired traits to be the parents of the next generationnext generation

This process has been used for hundreds of This process has been used for hundreds of yearsyears

Two Types:Two Types: Inbreeding- crossing two individuals that have Inbreeding- crossing two individuals that have

similar characteristicssimilar characteristics Hybridization- crossing two genetically different Hybridization- crossing two genetically different

individuals individuals

CloningCloning

Cloning- Cloning- a technique used to produce a technique used to produce offspring with desired traits (identical to the offspring with desired traits (identical to the traits of another organism) traits of another organism)

Clone- Clone- an organism that has identical gene an organism that has identical gene as the one from which it was producedas the one from which it was produced

WATCHWATCH - BrainPop: Dolly the Sheep - BrainPop: Dolly the Sheep

Genetic EngineeringGenetic Engineering

Genetic engineeringGenetic engineering- genes from one - genes from one organism are transferred into the DNA of organism are transferred into the DNA of anotheranother

Examples ….Examples ….

Gene therapy- Gene therapy- use of genetic engineering to use of genetic engineering to correct genetic disorders. correct genetic disorders.

Concerns…Concerns…

The Human Genome The Human Genome ProjectProject

Genome- Genome- all of the DNA in one cell of an organismall of the DNA in one cell of an organism

Goal of the Human Genome Project:Goal of the Human Genome Project: Identify the sequence of every gene in the human Identify the sequence of every gene in the human

genome genome

Interesting Facts:Interesting Facts: The DNA of humans consists of at least 30,000 genesThe DNA of humans consists of at least 30,000 genes Each gene has about 3,000 bases (A, T, G, C)Each gene has about 3,000 bases (A, T, G, C)

Other Uses:Other Uses: DNA FingerprintingDNA Fingerprinting

Technology used in the Human Genome Project can Technology used in the Human Genome Project can be used to identify people and show whether people be used to identify people and show whether people are relatedare related