Bio Topic 10 Flashcards
What is a pathogen?
A microorganism that causes disease
What is a transmissible disease?
A disease which can be passed between hosts
Give 5 ways diseases can be spread
Droplet infection (eg. sneeze of one person into another)
Eating contaminated food
Drinking contaminated water
Direct contact
Entry through wounds”
State 2 chemical defences the body uses to prevent infection
“Strong stomach acid kills pathogens
Mucus contains antimicrobial chemicals”
State 2 mechanical defences the body uses to prevent infection
1)Nasal hairs used to trap and waft dirt and
microbes to prevent entry into the airway
2)The skin acts as a barrier to pathogens
Give 2 ways that white blood cells protect the body from infection
“Phagocytosis (engulfing pathogens)
Producing antibodies which attach onto pathogens”
How do antibodies work?
“Specific antibodies bind to antigens on the pathogen
The antibodies can either destroy the pathogen or make the pathogen easier for white blood cells to engulf”
Why can only certain antibodies bind to certain pathogens?
Antibodies have specific shapes and can only bind to specific and complementary antigens on pathogens
What is active immunity?
Active immunity is a type of immunity where white blood cells produce specific antibodies against a pathogen
State 2 ways that active immunity can be obtained
Vaccination, Infection with the pathogen
How do vaccines work?
“Dead, inactive or weakened pathogens are injected
into the body
The body produces antibodies against the pathogen
Memory cells are also created to provide long term immunity”
Give 4 methods of controlling the spread of disease
-Hygienic food preparation (storing food in appropriate conditions, washing equipment)
-Good personal hygiene (using tissues, washing hands and cleaning regularly)
-Waste disposal (not letting rubish build up + throwing away used needles)
-Sewage removal and taking precautions to ensure it does not contaminate drinking water”
What is herd immunity?
Where the vast majority of a population are vaccinated which prevents the disease from spreading as there are fewer unvaccinated individuals for the disease to spread between
What is passive immunity?
Where an individual is provided with short term immunity by receiving antibodies from another individual (typically a mother to an infant)
Why is passive immunity only short term?
No memory cells are produced
