2. Diseases caused by abnormal chromosomes or by defective genes inherited from one or both parents.

3. Segments of DNA located on a chromosome that code for a specific hereditary trait

4. Occur when 1 gene out of 30,000 to 40,000 genes in the body has a harmful mutation.

5. When a gene carries incorrect instructions

6.  Nerve cells use a brain chemical called dopamine to help control muscle movement. Parkinson's disease occurs when the nerve cells in the brain that make dopamine are slowly destroyed. Without dopamine, the nerve cells in that part of the brain cannot properly send messages. This leads to the loss of muscle function.

7. Degeneration of brain cells

8. Blood disease in which the body produces defective hemoglobin.

9. Blood disease in which the body produces little or none of the blood proteins necessary for clotting.

10. Disease of the body’s mucous glands. It primarily affects the respiratory and digestive systems of children and young adults.

11. More than one gene influences the onset of a disease. Lifestyle behaviors can contribute to a person’s chance of developing a complex disease CVD’s such as stroke, high blood pressure, heart attacks, arteriosclerosis, type 2 diabetes and cancer are examples of complex diseases.

12. When a person inherits the wrong number of chromosomes or an incomplete chromosome. Humans normally have 23 chromosomes in each cell. Most common chromosomal disease in the U.S. is Down Syndrome.

13. If the immune system does not function properly it can result in an immune disorder. Examples of immune disorders are allergies, asthma and AIDS.

14. When the immune system attacks the cells of the body that the immune system normally protect.

15. Rheumatoid Arthritis is an autoimmune diseases are in which the immune system attacks the joints. Multiple Sclerosis occurs when the immune system attacks the fatty insulation of nerves in the brain and spinal cord.