1. Mutation CAUSES: Definition:
change in organism resulting from change in gene structure
CAUSES:
1. Errors in DNA replication:
nucleotides lost, rearranged, paired wrong
2. Mutagen:
internal or external factor causing mutation
Chemical mutagens:
dioxins, benzene, asbestos, DDT, cigarette smoke
Radioactive Mutagens:
UV rays, X-rays
3. Transposons:
DNA sequence capable of randomly moving from one site to another in another in the genome

2. Gene Mutations Frameshift Mutations (English Sentence Analogy):
Original:
BIG DOG BIT TED
Addition:
BIG DOG BBI TTE D
Deletion:
IGD OGB ITT ED
Substitution:
BIG JOG BIT TED
Point Mutations:
Silent:
DNA=ACA→ACG, mRNA=UGU→UGC, AA=Cys →Cys
Missense:
DNA=ACA→ACC, mRNA=UGU→UGG, AA= Cys→ Trp
Nonsense:
DNA=ACA→ACT, mRNA=UGU→UGA, AA=Cys→STOP

3. Genetic Mutations
Original Strand:
Addition:
Substitution:

4. Genetic Disorders Sickle Cell Anemia: Phenylketonuria (PKU): Albinism:
- valine replaces glutamate in amino acid chain of hemoglobin
- normal blood cells replaced by sickle shaped cells
- abnormal cells block blood vessels, normal cells cannot get
through, tissue starved of oxygen, nutrients
Phenylketonuria (PKU):
- tyrosine converted to phenylpyruvic acid
- acid build up causes nervous system damage,
mental retardation
Albinism:
- enzyme that converts tyrosine to melanin defective
- subjects will have no skin/hair pigment, appear almost
pure white

5. Chromosomal Mutations
Inversion
Translocation
Duplication
Deletion

6. Chromosomal Disorders
Down's Syndrome:
- extra chromosome #21
- facial features change
(mongolism), mental processing
slowed
Turner's Syndrome:
- absence of second X or Y chromosome
- person is single X – short infertile female
Kleinfelter's Syndrome:
- 3 sex chromosomes – XXY
- person is a male that grows tall with long limbs, generally have
IQ’s significantly below siblings
- sperm count may be reduced or person may be infertile