Communicable diseases

• What is a pathogen?


  A pathogen is a microorganism that causes a disease.
• The 4 types of pathogens are viruses, bacteria, fungi and

  protists
• Communicable diseases can be transmitted by air, water, ​or direct contact with an infected person.
• The tobacco mosaic virus infects tobacco and lots of other closely related species, such as tomatoes and peppers.
• The tobacco mosaic virus (TMV) infects chloroplasts in the leaves of the plants.
• TMV affects the plant’s ability to photosynthesise and grow properly.
• Measles, HIV, AIDS and Tobacco mosaic disease are examples of viral diseases.
• Viruses are not cells, they are very tiny and they can reproduce rapidly in our bodies.
• Rose black spot is an example of fungal disease.
• An example of a protist disease is malaria.
• Example of bacterial disease are Salmonella and Gonorrhea .