biology

• define the term pathogen?


  microorganism that enters you body causing disease
• what are bacteria?


  small living cells
• what are viruses?


  not cells and are much smaller than bacteria
• what are protists?


  single-celled eukaryotes e.g parasites
• describe how measle virus can be spread?


  droplets of and infected persons cough or sneeze
• where in the human body does HIV attack?

  Immune system
• how is HIV spread from person to person?


  body fluids from sexual contact e.g. blood and sharing needles
• how can fungal disease rose black spot be treated?

  fungicide and destroying infected leaves
• list symptoms of malaria ?


  repeat episodes of fever
• what is salmonella?


  type of bacteria that causes food poisoning
• how can you get salmonella?


  contaminated food or water
• what are symptoms of gonorrhoea?


  pain when urinating, thick green discharge from private area
• whats a problem with using antibiotics to treat gonorrhoea?

  certain strains are Antibiotic resistance
• what is the main way by which your body prevents pathogens getting inside?


  your skin acts like a barrier
• what are three ways that a white blood cell can destroy invading pathogens?

  consuming pathogens, producing antibodies and antitoxins
• what are antibodies?


  proteins made by white blood cells in response to foreign antigens. they are specific
• how do antitoxins work?


  counteract toxins produced by the bacteria
• how do vaccinations work?


  causes your body to make antibodies which will kill of the pathogens
• what are disadvantages of vaccination?


  dont always work and can have bad reactions
• why arent viruses killed by antibiotics?


  viruses reproduce using your own body cells making it difficult to kill them without kill your body cells
• why do resistant bacteria cause a problem during infections?


  arent killed by antibiotics meaning they will survive and reproduce increasing the size of the resistant populations
• what are three reasons new drugs are tested?

  1.toxicity(saftey)

  2.efficacy(do they work

  3.dose(how much do they take)
• why is preclinical testing carried out on live animals?

  to find out about the drug's toxicity and see if it is effective before using human volunteers
• what is a placebo?


  a dummy drug which looks like a real drug but doesnt do anything
• what is a double-blind clinical trial?


  when the patient and the doctor does not know whether it's a placebo or the real drug
• what is a communicable disease?

  caused by pathogens and can spread easily
• what do bacteria produce that make you feel ill?

  produce toxins which damages your cells
• how do viruses make more copies of themselves?

  reproduce inside your body cells. this damages the cells of your body
• what are three main ways pathogens can spread?


  through dirty water, air and direct contact
• what are the symptoms of measle disease?

  red skin rash, fever and extreme cases of pneumonia
• what are the symptoms for HIV?

  flu-like symptoms, after a few years the immune system become badly damaged as they can get infections and cancer
• what are the symptoms of tobacco mosaic virus (TMV)?


  leaves have a mosaic pattern on them meaning they can photosynthesise well
• what causes malaria?

  protist which is carried by mosquitos
• how can the spread of malaria be reduced?

  stopping mosquitos from breeding - using insecticides and mosquito nets
• what are the symptoms of food poisoning?

  fever, vomiting, diarrhoea
• how is the spread of salmonella prevented in the UK?

  most poultry are vaccinated against it
• how can the spread of gonorrhoea be prevented?

  treat the infections with antibiotics and use contraception like condoms
• what are four ways in which the spread of communicable disease can be prevented?

  being hygienic, destroying vectors, isolation and vaccination
• how does mucus stop pathogens getting inside your body?

  produced by the nose, trachea and bronchi. it is sticky so traps pathogens
• what is a antigen?

  unique molecules on the surface of every cell