2.5.1 - Infectious disease

• Health- State of physical, mental and social well being, which includes the absence of disease and infirmity (weakness of body or mind) 
• Disease is a condition that impairs the normal functioning of an organism. Can be caused by infection with pathogens or parasites. 
• Pathogen- An organism that can cause damage to the organism that it infects (the host) 
• Parasite- An organism that lives on or in another organism (the host) and causes damage to that organism. 
• Diseases can also be caused by genetic defects, nutritional deficiencies and environmental factors. Infectious diseases are diseases that can be passed between individuals 

Malaria:

Caused by the parasite Plasmodium. Plasmodium is a eukaryotic, single celled parasite. Its transmitted by mosquitoes. The mosquitoes are vectors- they don't cause the disease themselves, but they spread the infection by transferring the parasite from one host to another. Mosquitoes transfer the Plasmodium…