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MUTATIONS
Changes in DNA can cause changes in
phenotype.
Changes in the DNA sequence of
nucleotides is called a mutation.

Some mutations
have little or no
effect on an
organism, others
are harmful or
fatal, a few can
even be beneficial.

There are two
types of mutation:

1. Chromosomal involves the entire
chromosome.

2. Gene - involves
individual genes on
a chromosome.
4 types of chrom. mutations:

Deletion - chromosome breaks apart, and a piece is
lost.

Duplication - chromosome breaks apart, and the piece
incorporates into the homologous chromosome.

Translocation - chromosome breaks apart, and the
piece incorporates into a non-homologous
chromosome.

Inversion - chromosome breaks and reattaches in
reverse order.
There are 3 types of gene
mutations:

Frameshift - deletion or insertion of
nucleotides that disrupts codons.

Point or Substitution - change that occurs in
only one nucleotide.
Cancer is uncontrolled,
abnormal cell division

Caused when genes
that control
production of new
cells do not shut
off.

A gene that causes
a cell to become
cancerous is called
an oncogene.
Three ways a gene can become
an oncogene:

Mutation of a growth factor gene

An error in DNA replication

A change in a gene’s location