1. Don’t let this happen to you!!

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

3. 2 Main Types of Mutations
1.) Chromosomal Mutations
2.) Gene Mutations

4. What are chromosomes?
Humans have 23 pairs of chromosomes, with one chromosome from each parent.
The chromosomes are coiled up DNA.
Under normal conditions all of the chromosomes are inherited in tact.
This is a normal karyotype of human chromosomes. A karyotype is a picture of chromosomes lined up to look at and compare.

5. Chromosomal Mutations
Any change in the structure or number of chromosomes
Large scale: Affect many genes

6. 4 Types
Deletion
Duplication
Inversion
Translocation

7. One or more genes are removed
Chromosomal Deletion
One or more genes are removed
Causes:
Wolf-Hirschhorn syndrome (severe mental retardation)
cri du chat syndrome (mewing sounds, mental retardation)

8. Chromosomal Duplication
A segment of genes is copied twice and added to the chromosome
Causes:
Charcot–Marie–Tooth disease
(high arched foot, claw feet, confined to a wheelchair)

9. Chromosomal Inversion
a segment of genes flip end-to-end on the chromosome
Causes:
Four-Ring Syndrome
(cleft pallate, club feet, testes don’t descend)

10. Chromosomal Translocation
Material is swapped with another chromosome
Causes:
Burkitt’s Lymphoma
(cancer of the lymph nodes, in children)

11. Chromosome Mutations
Changes in number and structure of entire chromosomes
Original Chromosome ABC * DEF
Deletion AC * DEF
Duplication ABBC * DEF
Inversion AED * CBF
Translocation ABC * JKL
GHI * DEF

12. Gene Mutations Small scale: one gene is affected
Any change to the DNA sequence of a gene:
Nucleotides/Bases may be added, missing, or changed

13. Gene Mutations Point Mutations – changes in one or a few nucleotides
Substitution
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

14. Point Mutation One base (A, T, C, or G) is substituted for another
Causes: Sickle-cell anemia
3 Possible Consequences:
nonsense mutations: code for a stop, which can translate the protein
missense mutations: code for a different amino acid
silent mutations: code for the same amino acid

15. Gene Mutations
Frameshift Mutations – shifts the reading frame of 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

16. 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

17. 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

18. 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 inteligence.

19. 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

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

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

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

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

25. Some mutations even make it on SNL!