Biology Ka1 Flashcards
What causes an infectious disease?
A microorganism entering and attacking the body
What are pathogens?
Microorganisms that cause disease and can be: bacteria, viruses, Protists or fungi
How long does it take for a bacteria cell to divide?
20 minutes
What is the equation for magnification?
Image size = actual size x magnification
How does a bacteria make someone ill?
They release toxins into their host
How do viruses reproduce?
In other cells
How does a virus infect someone?
It attaches to a cell, injects DNA into it, replicates using host and new DNA is released
What happens to your body when a pathogen enters?
It reproduces rapidly, bacteria makes harmful toxins, viruses begin to damage cells, symptoms occur
How can diseases be spread?
- air (droplet infection)
- direct contact : wounds, touching , animal bite, vector organism
- sexually transmitted
- water and food
What are some ways to stop the spread of infection?
- clean water supplies
- sewage treatment
- hand washing
- personal hygiene
What conditions do microbes need to grow?
- oxygen
- food
- warmth
- moisture
- correct pH
- correct salt concentration
What are some examples of viral diseases?
AIDs, measles
What are some examples of bacterial diseases?
salmonella, cholera
What are some examples of fungal diseases?
Rose black spot
What are some examples of protist diseases?
Malaria
How does the skin help when fighting an infectious disease?
It acts as a barrier, produces antiseptic oils
How do scabs help fight diseases?
Clots form to seal wounds so bacteria doesn’t get in
How does the breathing system help when fighting diseases?
Mucus traps pathogens and cilia help remove it
How does stomach acid help fight against disease?
Helps to destroy the pathogens
How do enzymes help fight disease?
Special enzymes in urine, tears and saliva kill bacteria
How do white blood cells help in the fight against disease?
They produce antibodies which destroy certain bacteria
What are antitoxins and where do they come from?
White blood cells produce them to neutralise toxins made by bacteria
How does the immune system work to provide immunity?
White blood cells react to a pathogen, they will ingest the pathogen and produce antitoxins. If this works fast enough, the pathogens will be killed, the next time u get the pathogen your white blood cells will already be ready to attack. If not the pathogens overwhelm the body and you will become sick or die.
What are the types of vaccine?
- live altered pathogens
- dead pathogens
- active immunity
- passive immunity
What is active immunity?
White blood cells which produce a specific antibody have been produced to provide a permanent immunity
What is passive immunity?
Antibodies are directly given, they only provide temporary immunity
Why did so many children catch measles in 2001 and not adults?
Because most of the adults were already immune to the disease because of past infection, and they didn’t catch it a second time because there were already enough white blood cells ready to attack the pathogen
What is the difference between antibodies and antitoxins?
Antibodies destroy pathogens, antitoxins neutralise toxins produced by pathogens
How does the flu vaccine work?
It stimulates your body’s immune system to make antibodies to attack the microbes. The antibodies are proteins that recognise and fight the pathogens
What happens if u catch the flu after you’ve had the vaccine?
Your white blood cells recognise the virus and immediately produce antibodies to fight it
What type of immunity is the flu
Active immunity
How is a flu vaccine made?
Antigens are separated from a microbe
