1. Changes in DNA that affect genetic information
MUTATIONS
Changes in DNA that affect
genetic information

2. DNA Mutations Any change in DNA sequence
Can be caused by errors in replication, transcription, cell division or by external agents
Three types: point, frameshift and chromosome

3. Point Mutations A change in a single point in DNA
This change can alter the entire structure of a protein due to the change in a single amino acid.

4. Point Mutations Three Types Substitution Insertion Deletion
THE FAT CAT ATE THE RAT
THE FAT HAT ATE THE RAT
Insertion
THE FAT CAT XLW ATE THE RAT
Deletion
THE FAT___ ATE THE RAT

5. Frameshift Mutations
A single base change added or deleted from the DNA strand
Shifts the reading of the codons by one base

6. Frameshift Mutations
Shifts the genetic message so that the protein may not be able to perform its function.
Insertion
THE FAT CAT ATE THE RAT
THE FAT HCA TAT ETH ERA T
Deletion
TEF ATC ATA TET GER AT H H

7. Chromosome Mutations
Changes in number and structure of entire chromosomes
Original Chromosome ABC * DEF
Deletion AC * DEF
Duplication ABBC * DEF

8. Significance of Mutations
Most are neutral
Eye color
Birth marks
Some are harmful
Sickle Cell Anemia
Down Syndrome
Some are beneficial
Sickle Cell Anemia to Malaria
Immunity to HIV

9. What Causes Mutations?
There are two ways in which DNA can become mutated:
Mutations can be inherited.
Parent to child
Mutations can be acquired.
Environmental damage
Mistakes when DNA is copied

10. Mutations in Sex Cells
May produce a new trait or may result in a protein that does not work correctly
In some rare cases, it may have a positive effect
Can be passed on to offspring

11. Mutations in Body Cells
If a body cell’s DNA is changed, this mutation would not be passed on to offspring.
It may cause problems for the individual
Damage to a gene may impair the function of the cell.
Can result in the cell growing and dividing rapidly, causing cancer.

12. Causes of Mutations Mutagen – anything that can cause a change in DNA
Include radiation, chemicals and even high temperatures

13. Chromosome Mutations Down Syndrome
Chromosome 21 does not separate correctly.
They have 47 chromosomes in stead of 46.
Children with Down Syndrome develop slower, may have heart and stomach illnesses and vary greatly in their degree of intelligence.

14. Chromosome Mutations Cri-du-chat
Deletion of material on 5th chromosome
Characterized by the cat-like cry made by cri-du-chat babies
Varied levels of metal handicaps

15. Sex Chromosome Abnormalities
Klinefelter’s Syndrome
XXY, XXYY, XXXY
Male
Sterility
Small testicles
Breast enlargement

16. Sex Chromosome Abnormalities
XYY Syndrome
Normal male traits
Often tall and thin
Associated with antisocial and behavioral problems

17. Sex Chromosome Mutations
Turner’s Syndrome X
Female
sex organs don't mature at adolescence
sterility
short stature

18. Sex Chromosome Mutations
XXX
Trisomy X
Female
Little or no visible differences
tall stature
learning disabilities
limited fertility