12-4 mutations objective: contrast gene mutations & chromosomal mutations are all mutations bad?
TRANSCRIPT
12-4 Mutations
Objective:Contrast gene mutations & chromosomal mutations
Are all mutations
bad?
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:
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
Protien: Leu-Glu-Ser-Asp
Original
DNA: G A T C T A A G G C T A
mRNA: C U A G A U U C C G A U
Protien: Leu-Asp-Ser-Asp
Mutation
Oops!
Kinds of Mutations
• Chromosomal Mutations: change entire DNA– Frameshift mutations occur when the entire
reading frame changes.– Ex: A nucleotide gets added (insertion).
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
Protien: Leu-Glu-Ser-Asp
Original
DNA: G A T C T A C A G G C T A
mRNA: C U A G A U G U C C G A U
Protien: Leu-Asp-Val-Arg
MutationA
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).
DNA: G A T C T A G G C T A
mRNA: C U A G A G U C C G A U
Protien: Leu-Glu-Ser-Asp
Original
DNA: G A T C T A G G C T A A
mRNA: C U A G A U C C G A U U
Protien: Leu-Glu-Ser-Iso
Mutation
C
Kinds of Mutations
• Chromosomal Mutations: change entire DNA– Change in number of chromosomes.– Ex: Down Syndrome (47 chromosomes)