Mutations
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Transcript of Mutations
Mutations
• Hollywood’s images of mutation
Mutations
• Actual Mutations in fruit flies
What is a mutation?
• A mutation is any change in a cell’s DNA• A mutation can occur in an individual gene - results in a single changed protein - cystic fibrosis a mutation in the protein that
makes a type of ion channels in cell membrane - bacterial resistance to antibiotics is an example
of a beneficial gene mutation
What is a mutation continued
• A mutation can occur in a chromosome - a chromosome contains many genes - chromosomal mutations affect many proteins Examples: Down Syndrome Edward’s Syndrome Cri-du-Chat
What Causes Mutations?
• Can be caused by mutagens- a physical or chemical cause of mutation. Examples: UV light, radiation, drugs, and benzene.
• Mutagens are often also carcinogens – anything that causes cancer
• Can be natural, random events. - mutations occur in 1/100,000 DNA replications• Mutations do not have to be bad (evolution)
Point Mutations
• A single nucleotide is altered. Can change one amino acid in a protein
• Example of a point mutation is a substitution• Milk – Mile• GGACAATCA GGACCATCA proline -valine-serine proline-glycine-serine
Frameshift Mutations
• A nucleotide is either inserted or deleted from a gene.
-all of the triplets from the point of mutation onward will be changed
Frameshift Mutations Insertion
• An insertion occurs when a nucleotide is added to a gene
Example: A nucleotide is inserted The fat cat ate the rat
The faa tca tat eth era t -the extra nucleotide shifts all of the triplets
that follow
Frameshift Mutations Deletions
• A deletion occurs when a nucleotide is removed from a gene.
Example: A nucleotide is removedThe fat cat ate the rat
Thf atc ata tet her at
Insertion• GGACAATCA GCGACAATCA proline -valine-serine arginine-cysteine-stop
Deletion• GGACAATCA GGAAATCA proline -valine-serine proline-leucine
Vocabulary
• Mutation• Mutagen• Carcinogen• Point mutation• Frameshift mutation - insertion - deletion
MutationsChromosomal Mutation:
change in the structure or number of chromosomes in a cell; usually caused by problems during meiosis or a mutagenMutagen:
an agent that causes a DNA mutationEx: UV, radiation…
Chromosomal MutationsDeletion: a mutation in which part of the chromosome or a sequence of DNA is missing
Chromosomal Mutations
Duplication: a mutation in which part of the chromosome or a sequence of DNA is repeated
Chromosomal MutationsInversion: a mutation in which part of the chromosome or a sequence of DNA is flipped or rotated
Chromosomal MutationsTranslocation: a mutation in which part of the chromosome or a sequence of DNA is removed from one chromosome and relocated or attached to another chromosome