B3 Flashcards
What is a pathogen
Microorganisms that cause disease
Name 4 types of pathogens
Viruses
Bacteria
Fungi
Protists
Give example of viruses
HIV potentially leading to AIDS
Tobacco mosaic virus- plant
Example of bacteria
Salmonella
Agrobacterium -plants
Examples of Fungi
Athlete’s foot
Rose black spot - plants
Examples of protists
Malaria
Downy mildew - plants
What is bacteria
Small cells that reproduce very quickly in the body. They produce toxins that make you feel ill, damaging your cells and tissues
What are viruses
Smaller than Bacteria, can reproduce quickly in the body. Viruses live inside your cell where they replicate. They then burst out of the cell, releasing new viruses
What are protists
Are eukaryotes (multicellular). Some are parasites which live on or inside other organisms, often carried by a vector
What are fungi
Sometimes single celled, others have hyphae that grow and penetrate human skin and the surface of plants
How are pathogens spread
Water - by drinking unclean water
Air - carried by air breathed in
Direct contact - touching contaminated surfaces
How does your body act against pathogens
- skin acts as barrier
- stomach has hydrochloric acid to kill
- nose hair and eyelashes
- the immune system
How do white blood cells act against pathogens
Phagocytosis- wbd engulf pathogens + digest them
Produce antitoxins to neutralise toxins
- antibodies- lock on to antigen which is located on the pathogen’s surface and then destroy the pathogen
3 stages of drug testing
1) drugs tested on human cells and tissues
2) testing carried out on living animals
3) tested on healthy humans volunteers in clinical trials
