what is a mutation???. genetic mutations mistakes in dna
TRANSCRIPT
What is a mutation???
GENETIC MUTATIONS
MISTAKES IN DNA
A MISTAKE CAN BE:
1. A point mutation – substitution, addition, or removal of a single DNA base.
2. A frameshift mutation – a point mutation due to an addition or deletion of a DNA base that causes a major change in the genetic code.
Sickle cell anemia is caused by a point mutation - substitution
Val-his-leu-thr-pro-glu-glu
Val-his-leu-thr-pro-val-glu-
Muscular Dystrophy is caused by a frameshift mutation
THE CAT SAW THE DOG
CHANGE THE W TO A T:
THE CAT SAT THE DOG
CHANGE THE D TO AN H
THE CAT SAW THE HOG
MAJOR MISSENSE: REMOVE THE “C”
THE ATS AWT HED OGThis type of mutation causes a protein to be non-functional. It is a severe problem and can be lethal.
MAJOR MISSENCE: INSERT AN “M” after the first “The”.
THE MCA TSA WTH EDO G
The body cannot make sense out of the incorrect protein, just as the sentence no longer makes sense to you.
Nonsense• When a point mutation codes for a STOP in
the middle of a sequence. Could be due to any of the point mutations.
Nonfunctional dystrophin, the protein that helps attach your skeletal muscle to its surroundings.
Some mutations involve whole chromosomes:
1. Deletion: A piece of a chromosome is lost because of breakage during cell division
Cri du chat
Inversion: A piece of a chromosome breaks off and reattaches backwards.
The effect can be lethal.
Duplication: A portion of the chromosome is copied and placed
in the same chromosome.
Translocation: a piece of a chromosomes breaks off and
reattaches to a non-homologous chromosome
Non-disjunction: A chromosome fails to separate from its
homologue during meiosis
Turner’s Syndrome:
Klinefelter’s Syndrome:
Mutations in nature:
