Microbes And Defence Against Disease Flashcards
What are the three microbes?
Bacteria
Fungi
Viruses
What are the 3 types of bacteria?
Describe them
Cocci - are spherical in shape
Bacilli - are rod shaped
Spirochetes - are spirals
Some may have a long filament called a flagellum attached - this allows them to move
Why is bacteria dangerous?
Bacteria are responsible for numerous illnesses including MRSA, salmonella and tuberculosis. They also cause food to go off.
How can bacteria be useful?
Some are very useful to hormones - eg. For the production of yoghurt, treating sewage and in genetic engineering.
Describe fungi.
They have a spore case and a network of threads forming a structure called mycelium.
What is fungi dangerous?
They are responsible for athlete’s foot infection as well as ringworm. They also spoil food eg. Bread mould
Why are fungi good?
Yeast is probably the best known fungus. It is used in the baking and brewing industries. Fungi is also used in the cheese industry - smelly blue cheese
Describe viruses.
The structure is a head capsule (that contains DNA) with a long tail with an end plate attached.
What are viruses dangerous?
Viruses cause many diseases including all flu - (influenza virus), chicken pox, mumps and AIDS (the HIV virus). Flu viruses can change into many different forms meaning your u cannot be immune to the flu.
Why can viruses be useful?
Humans can also make use of the viruses In genetic engineering.
Name 3 major shapes bacteria can be
Rod
Spiral
Spherical
As bacteria grow rapidly each individual microbe from your chosen source will divide again and again giving rise to a group of bacteria on the surface of the agar.
These groups are called…
Colonies
Give an example of when aseptic technique may be used
To study bacteria and other microbes effectively .
If you are growing microbes to study them to see where they come from
Give three measures that are taken when working under aseptic conditions
Wash your hands
Wear goggles
Tuck your tie in
Why is it recommended to work close to a Bunsen when making growth plates?
To stop bacteria from the air falling into the jar
Why do you think it is necessary to flame the neck of the bottle of agar?
Kills any microbes to stop them getting in the jar
Why do you incubate your Petri dish upside down?
Stops condensation.
Why would it be dangerous to incubate growth plates at 37°C?
We don’t want to grow things at our body temperature because they can grow in our bodies.
What is an out brake?
When a disease spreads suddenly through a large population.
What type of virus is the flu?
Caused by the influenza virus
What are the symptoms of the flu?
Vomiting Fever Aches and pains Diarrhoea Coughing Sore joints
What had to happen to swine flu to allow it to infect humans?
Mutate to infect humans
Where were the first cases of swine flew reported?
Mexico
How can the swine flu be spread?
Sneeze or cough
