Download Section 11.3

Section 11.3
Genetic Changes
Mutations

Any change in the DNA sequence that also
changes the protein it codes for.
Mutations in reproductive cells:



May produce a new trait
May result in a protein that does not work
correctly
Protein may be nonfunctional causing the
embryo to not survive
Mutations in body cells:

Would not be passed
on to offspring

May impair the
function of the cell

cancer
Point Mutation

The change in a single
base pair in DNA

Can change a single
amino acid in the
chain resulting in a
change in the entire
protein produced.
Frameshift Mutation

A mutation in which a
single base is added
or deleted from DNA

Would cause nearly
every amino acid in
the protein after the
addition or deletion to
be changed.
Chromosomal Mutation

When parts of chromosomes are broken
off or lost during mitosis or meiosis

Chromosomes break and rejoin incorrectly

Usually do not survive. If they do, they
are usually sterile
Types of Chromosomal Mutations:

1. Deletion – when part of
a chromosome is left out

2. Insertions – when a
part of a chromatid breaks
off and attaches to its
sister chromatid. The
result is a duplication of
genes on the same
chromosome.
Types of Chromosomal Mutations

3. Inversions – when
part of a chromosome
breaks off and is
reinserted backwards.

4. Translocations –
when part of one
chromosome breaks
off and is added to a
different chromosome.