B2 - Keeping Healthy Flashcards
Why can bacteria reproduce very quickly inside the human body?
The warm, moist conditions and good supply of nutrients inside the human body are ideal conditions for the bacteria to multiply in.
How do you microorganisms cause of the symptoms of infectious disease?
Microorganisms are the damage cells directly, or produce toxins that can damage or poison them.
Rebecca has a culture of 30 bacteria. She knows that they reproduce once every hour. How many bacteria will she have if she leaves the culture for three hours?
240 bacteria
Dimitar has recently had a disease. Explain what will happen if he is infected again soon?
Dimitar’s immune system has produced memory cells against the disease. When the microorganism re-enters his body, Dimitar’s white blood cells will recognise the antigens, which will cause his memory cells to quickly reproduce and produce loads of antibodies to kill off the microorganism.
How do I do blood cells defend the body against microorganisms?
White blood cells can in golf and destroy microorganisms, or produce antibodies against microorganisms.
How does the immune system recognise invading microorganisms?
Antibodies and white blood cells recognise microorganisms by the antigens they carry on their surface.
What do you need to know to be able to work out the number of microorganisms in a population after a certain period of time?
The number of microorganisms that are present to begin with, how long it takes for the microorganisms to reproduce once and the amount of time the microorganisms are left for.
What do you vaccines contain?
A safe form of a disease-causing microorganism
Explain why vaccinations aren’t always safe.
Genetic differences mean that people react differently to vaccinations. So some people have no negative reaction, but others may experience my not all serious side-effects.
How do vaccinations protect people from diseases?
The safe form of microorganism that is in the vaccine carries antigens. White blood cells produce antibodies in response to these antigens even though the microorganism is harmless. Memory cells are also produced. This means that if the person is re-infected with the same microorganism, the memory cells can quickly reproduce and mass-produce antibodies to destroy the microorganism.
80% of the population into town are vaccinated against measles. How does this reduces the risk of getting measles for those who aren’t vaccinated?
If a large percentage of the population have been vaccinated, fewer people will get measles, this means that there will be less people to pass it on to the people who haven’t had the vaccination.
