B5 Flashcards
Bacteria uses
To make food like yoghurt and cheese
To treat sewage
To make medicines
Binary fission
Bacteria dividing rapidly by splitting into two, which may produce toxins(poisons) that affect your body and make you feel ill
How do pathogens spread from one individual to another
By air/droplet infection
Direct contact
By water
How are pathogens carried by air/droplet infection
When you are ill, you expel tiny droplets full of pathogen from of your breathing system which other people breathe in, so they pick up the infection
How are pathogens carried by direct contact
Some diseases are spread by direct contact of an infected organism with a healthy one
e.g. A tiny piece of infected plant material infects a new crop.
In people, doseases including sexually transmitted infections are spread through direct contact of the skin: direct sexual contact, cuts, scratches and needle punctures giving access to the blood
How are pathogens carried by water
Fungal spores carried in splashes of water often spread plant diseases, but for humans, eating raw, undercooked or contaminated food/drinking water containing sewage spread diseases like diarrhoeal diseases, cholera or salmonellosis.
Body defence system
1) The skin acts as a barrier to pathogens.
2) Hairs and mucus in your nose trap particles.
3) The trachea and bronchi secrete mucus to trap pathogens. They also have cilia which move backwards and forwards to transport the mucus towards the throat. This traps any pathogens and the mucus is usually swallowed.
4) The st9mach contains hydrochloric acid to kill any pathogens entering the body via the mouth.
Cons of vaccinations
They don’t always work
Immune system defence
This kills any pathogens entering the body.
White blood cells:
Phagocytosis is when white blood cells engulf pathogens and then digest them.
They produce antitoxins to neutralise the toxins.
They also produce antibodies. Pathogens have antigens on their surface, antibodies produced by the white blood cells lock on to the antigen on the outside of the pathogen. White blood cells can then destroy the pathogens. Antibodies are specific to one antigen and will only work on that pathogen.
Salmonella treatment
Most poultry in the UK will have had a vaccination against salmonella
How to prevent the spread of gonorrhoea
Use of condom
People should be treated with antibiotics
How to prevent the spread of bacterial diseases
Being hygienic - washing hands thoroughly.
Destroying vectors - killing vectors by using insectides or destroying their habitat.
Isolation - isolating an infected person will prevent the spread.
Vaccination - people can’t develop the infection and pass it on
Measles treatment
Vaccination
Measles impacts
Could lead to pneumonia
Measles treatment
Most people are vaccinated against measles when they are very young
