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12-4 Mutations. Are all mutations bad?. Objective: Contrast gene mutations & chromosomal mutations. What is a mutation?. Changes in genetic information. Usually occurs in DNA replication. Kinds of Mutations. Gene Mutations: only changes 1 gene
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12-4 Mutations Are all mutations bad? Objective: Contrast gene mutations & chromosomal mutations
What is a mutation? • Changes in genetic information. • Usually occurs in DNA replication.
Kinds of Mutations • Gene Mutations: only changes 1 gene • Point Mutations occur when 1 or a few nucleotides change. • Ex: Oops! Original Mutation DNA: G A T C T C A G G C T A DNA: G A T C T A A G G C T A mRNA: C U A G A G U C C G A U mRNA: C U A G A U U C C G A U Protien: Leu-Glu-Ser-Asp Protien: Leu-Asp-Ser-Asp
Kinds of Mutations • Chromosomal Mutations: change entire DNA • Frameshift mutations occur when the entire reading frame changes. • Ex: A nucleotide gets added (insertion). A Original Mutation DNA: G A T C T AC A G G C T A DNA: G A T C T C A G G C T A mRNA: C U A G A G U C C G A U mRNA: C U A G A UG U C C G A U Protien: Leu-Glu-Ser-Asp Protien: Leu-Asp-Val-Arg
Kinds of Mutations • Chromosomal Mutations: change entire DNA • Frameshift mutations occur when the entire reading frame changes. • Ex: A nucleotide gets added (insertion). • Ex: A nucleotide gets taken away (deletion). Original Mutation DNA: G A T C T A G G C T A C DNA: G A T C T A G G C T A A mRNA: C U A G A G U C C G A U mRNA: C U A G A U C C G A U U Protien: Leu-Glu-Ser-Asp Protien: Leu-Glu-Ser-Iso
Kinds of Mutations • Chromosomal Mutations: change entire DNA • Change in number of chromosomes. • Ex: Down Syndrome (47 chromosomes)