1. Mutations
Curly winged fruit flies Drosophila, short leg bassett hounds and seedless grapes are all examples of mutations

2. Mutations- definition
Mutation is a change or a mistake in DNA replication. Mutations can arise in from changes in individual genes or changes in the arrangement of genes on a chromosome

3. Types of mutations There are two types of genetic mutations
Gene mutation
point mutation
chain termination mutation
frameshift mutation
chromosomal mutation

4. Point Mutation
A point mutation is a single base pair change by physical or chemical means, where a nucleotide is replaced by a different type.
A nucleotide can have a BASIC SUBSTITUTION of a base pair.
Ex. Guanine changed to Adenine

5. Basic substitutions
There can be three outcomes for a basic substitution
1) silent mutation- NO EFFECT
ex. UCU, UCC, UCA, UCG are all the mRNA code for Serine amino acid. These changes would have no effect.
Also there are many genes which do not have an effect on the body, a change in these genes would not cause a change

6. Basic substitutions Cont.
2) Neutral effect- A mutation that would change the structure of the protein but have little effect on its function
3) Drastic effect- a small change in one AA would seriously effect the structure and function of the protein
ex. Sickle cell Anemia- a change in one AA changes the shape of the hemoglobin of the RBC

7. Deletion
A deletion is when nucleotide is left out of a sequence of AA. Leaving out a nucleotide will cause a shift in the DNA and result in a synthesis of a polypeptide with an altered AA sequence.

8. Point mutations

9. Insertion
Similar to deletion, a nucleotide inserted in a sequence can cause a mutation in the protein beyond the point of the extra nucleotide.
In both deletion and insertion the polypeptide formed by the mutated gene, if one can be formed at all, is usually not functional.

10. Chain Termination Codon mutation
There are three codons ( Three base pairs) that tell the AA to stop adding to the proteins - UAA, UAG, UGA. When tRNA sees this code it stops making the protein. If there is a change in one of these codons it will have a lethal effect since the protein will stop growing or continue to grow.

11. Chromosomal mutations
Changes can occur in the chromosome as well as in the genes. Chromosomal mutations can happen in different ways.
Ex. a piece of the chromosome may break off or lost during mitosis.
Some of the chromosomal mutations can be repaired, others repair themselves in correctly.

12. Chromosomal mutations

13. Cancer
We now know that normal cells can be transformed into malignant cancerous cells. Gene mutations are ultimately to blame. Mutant forms of genes, ONCOGENES, result in abnormal proteins that disrupt the normal reproduction of cells and cause cancer. Oncogenes can be caused by a number of ways- by carcinogens (cancer causing substance (smoking, chemicals ); UV or X-rays

14. Cancer pictures

15. Mental retardation
A gene mutation responsible for a form of mental retardation affecting one in 600 males has been located on the X chromosome.

16. Mutation Disease- Sickle cell anemia
One in 500 people of African decent has sickle cell anemia, which is a disease that changes the shape of the hemoglobin protein. There is just one nucleotide difference in the sequencing of this protein. These blood cells can block capillaries in the body and cause pain, fever or even strokes and paralysis. Most people don't live past 40 years of age.

19. Benefits of mutations
Although most people think of mutations as harmful to or individual they can be helpful to an organism. Mutations of genes is cause of natural variation and one of the ways that organisms evolve. Gene mutations can have helpful results, allowing us to adapt to changes in the environment and survive as a species.

20. Examples of genetic diseases -Inherited or mutation
Acute intermittent porphyria
adult polycyctic kidney disease
albinism
alkaptonuria
BRCA breast cancer
cystic fibrosis
down syndrome
Duchenne muscular dystrophy
fragile x syndrome
hemophilia
Huntington disease
Neurofibromatosis
Phenylketonuria
Polyposis of the colon
Sickle cell Anemia
Tay-Sacs disease
Thalassemia