B3 - infection and response

• Pathogens are microorganisms that cause communicable (infectious) diseases
• Bacteria, viruses, fungi protists are all types of pathogens
• Diseases can be spread by air (by breathing and airborne pathogens) by direct contact ( by touching contaminated surfaces) through eating contaminated food through exchanging infected bodily fluids
• Bacteria produces toxins (poisons) that can damage an organisms cells and tissues
• Fungi can grow hyphae ( thread like structures) that can cause disease by penetrating skin and the surface of plants. The hyphae can also produce spurs which can be spread into other animals and plants.
• Rose black spots is caused by a fungus it is spread by water or wind (when infected plants touch each other)
• Two Simpsons of measles is red skin rash and a fever. It’s spread by inhaling droplets (which carry the virus) from an infected person sneeze or cough
• One way that the spread of malaria can be controlled is to prevent mosquitoes (the vectors of malaria) or by using mosquito nest to prevent mosquitoes from biting people
• HIV can be spread by sexual contact and by the sharing of needles between drug users this is because HIV spreads through the exchange of bodily fluids the sharing needles can cause an exchange of blood
• If HIV isn’t successfully controlled with antiretroviral drugs the virus will attack the immune cell and overtime. The immune system will become so damaged that it can no longer cope with other infections or cancer. This is called late stage HIV infection or aids.
• Tobacco mosaic viruses a virus and is spread by touching of affected plants
• Malaria is a protest and spread by mosquitos.
• Gonorrhoea is sexually transmitted disease. STD it spread through sexual contact.
• Bacteria causes salmonella, which is spread by eating undercooked meat (especially chicken)
• Vaccinations prevent people from developing communicable diseases and passing them on to others
• A vaccine contains an antigen from the pathogen. When injected into your body, your immune cells recognise this as foreign and produce antibodies against it. If you are then exposed to the real pathogen, your immune system has already produced antibodies to fight it off. You won't get sick because your immune system knows how to deal with the pathogen.
• Phagocytosis engulf and digest the pathogens which helps defend against them
• White blood cells produce antioxidants, which counteract toxins produced by invading bacterial pathogens
• The stomach produces hydrochloric acid which kills pathogens that reach the stomach
• Specific antibodies are produced by white blood cells to lock onto specific antigens on a pathogen (an antigen is a unique molecule on the surface of a cell) this is so the pathogen can be found and destroyed. The antibodies are rapidly multiplied and transported around the body to find similar pathogens.
• a vaccine is when a person is injected with a small amount of dead or an active pathogens the immune system produces antibodies specific to the antigens in the pathogens in the future if the person is infected by the Liv version of the same pathogen and their white blood cells can rapidly produce antibodies needed to kill it off
• If most of the population has had the vaccination then even the people who have not been vaccinated are unlikely to get some disease because there are fewer people who are able to pass on
• Antibiotics only work on bacteria
• Penicillin was discovered by Alexander Fleming he found that the penicillium mould on a petri dish of bacteria was producing a substance which killed the bacteria
• Bacteria can mutate and sometimes this causes them to become resistant to antibiotics when a person is infected and treated with antibiotics. The non-resistant bacteria will be killed and the resistant bacteria will survive and reproduce increasing the population of the resistance strain
• Pre-clinical testing is drug testing on live laboratory animals whereas clinical testing is carried out on humans
• When a patient has been given a placebo, this means they have been given a substance that looks like the real drive but does not do anything
• The results for clinical drug trial have been collected in analyse they must go through a pair of view which helps prevent false claims before they can be published
• A drug must be tested for toxicity ( how harmful it is) efficiency (whether it works and produces the decide effect) and dosage (the concentration that should be given and how often it should be given) To make sure that the drug is safe and efficient
• A double blind trial is when the patients are randomly split into two groups. One group is given the drugs and the other group is given a placebo in a double blind trial neither the doctors nor the patients know which patient has been given the drug and which have been given the place until after the results have been gathered this is so that no one is influenced by their knowledge. The results from both the groups are compared to learn how well the new drug works.
• Tumour cells can be grown easily because they divide a lot
• The uses of monocultural antibodies include pregnancy testing detecting pathogens measuring levels of hormones and other chemicals in the blood and locating or identifying specific molecules in cells or tissues
• If a plant has a lack of nitrate ions, its growth will be stunted. This is because the nitrates are needed to make proteins for growth.
• Some plants produce antibacterial chemicals to kill bacteria and some plants, but she’s poisoned to de herbivores (organisms that eat plants)
• Common signs of plant disease include stunted growth spots on leaves areas of decay or rot growth and malformed stems or leaves discolouration and the presence of Pests