Protein SynthesisTypes of Mutations Graphic Organizer

Point vs. Gene Mutations

Point Mutations only affect a SINGLE nitrogen base.

May not cause any noticeable mutation if the amino acid is not changed.

May also occur in the buffer or junk zones of DNA

Chromosomal Mutations affect entire or sections of a chromosome

Multiple Genes are affected

Always causes some type of change.

Substitution

One Nitrogen base is replaced with another nitrogen base.

Total number of bases in the sequence does not change.

MISSENSE – amino acid does change

NONSENSE – amino acid is changed to a STOP

SILENT – amino acid does not change

Insertion

• An extra base is inserted into the sequence.

• The number of bases will increase

• This is also called a FRAMESHIFT

Deletion

• A base is removed or deleted from the sequence.

• The number of bases will decrease.

• This is also called a FRAMESHIFT

Deletion

• A section of the chromosome is removed or deleted.

• The chromosome becomes shorter.

• Smith Magenis Syndrome is an example

Duplication

• Sections of the chromosome are repeated or copied.

• They have extra genetic material

• Oncogenes (genes linked to cancers such as Breast, Ovarian, Colon Cancers) are the result of duplication mutations

Inversion

• A portion of the chromosome has broken off, turned upside down and reattached.

• The order of the genes and bases has been changed.

• An inversion of Chromosome 9 is known to lead to an increase in miscarriages or infertility.

• Most common inversion in humans.

Translocation

• A portion of one chromosome is transferred to another chromosome

• Some cancers, infertility issues and Down Syndrome (Trisomy 21) have been linked to Translocation mutations.