Biology 1.2 : Pathogens + Fighting Diseases

PATHOGENS

PATHOGEN: microorganisms that cause infectious disease

2 MAIN TYPES OF PATHOGEN:

• BACTERIA
• VIRUS

BACTERIA

BACTERIA = very small LIVING CELLS

They make you feel ill by:

• DAMAGING YOUR CELLS
• PRODUCING TOXINS (poisons)

Diseases caused by bacteria include:

• food poisoning
• cholera
• typhoid
• whooping cough

VIRUSES

VIRUSES = NOT CELLS - much smaller

Make you feel ill by:

• INVADE YOUR CELLS
• USE THE HOST CELL MACHINERY TO PRODUCE COPIES OF THEMSELVES
• CELL USUALLY BURSTS RELEASING ALL THE NEW VIRUSES

This CELL DAMAGE makes you feel ill

Diseases caused by viruses include:

• influenza (flu)
• colds
• measles
• mumps
• rubella
• chicken pox
• AIDs

FIGHTING DISEASE

HUMAN BODY DEFENCE SYSTEM

TO PREVENT MICROORGANISMS GETTING IN THE BODY

• SKIN + HAIRS & MUCUS in RESPIRATORY TRACT (breathing pipework)

TO PREVENT MICROORGANISMS GETTING…