B3-Infection and response

• pathogens are microorganisms that enter the body and cause disease
• pathogen cause communicable disease
• viruses are not cells they are tiny and reproduce rapidly, they burst releasing all the new viruses and this is what makes you feel ill
• protists are eukaryotes
• pathogens can be spread by water, bacterial infection, air and direct contact
• measles is a viral disease and is spread by by droplets in the air. it causes red skin rash, fever
• HIV is a virus spread by sexual contact or bodily fluids like blood. it starts with a flu-like symptoms. the virus attacks the immune cell
• Tobacco mosaic virus it causes a mosaic pattern on the leaves of the plant it then causes discolouring meaning photosynthesis cant take place
• rose black spot is a fungal disease that causes black or purple spots on leaves and then leaves can then turn yellow and drop off. it spreads through water and wind
• malaria is caused by a protist. its spread by mosquitos and causes repeating fevers
• salmonella is caused by food poisoning and causes fever, cramps and vomiting
• gonorrhoea is a STD and is caused by bacteria and symptoms include pain when urinate and yellow and green discharge
• body can defend itself by skin, hairs and mucus and hydrochloric acid in the stomach that kills pathogens
• immune system attacks pathogens with white blood cells engulfing and digesting. its called phagocytosis
• every invading pathogen has a unique molecules called antigens
• when some types of white cells come across a foreign antigen they produce white blood cells and proteins to lock onto invading cells so they can be found and destroyed. the antibodies are specific to that type of antigen they wont lock onto any others
• antibodies are produced rapidly
• if the person is reinfected with the same pathogen again the white blood cells will rapidly produce the antibodies to kill it. the person is naturally immune to that pathogen and wont get ill
• antibodies

  A) antigens

  B) white blood cell

  C) antibodies are produced

  
• producing antitoxins counteract toxins produced by invading bacteria
• vaccinations involve injecting small amounts of dead or inactive pathogens
• vaccination

  A) pathogens

  B) antibodies produced

  C) white blood cells

  
• vaccinations help control communicable disease and large epidemics can be prevented however they don`t always work and can cause side effects
• painkillers relive symptoms not cure the disease
• antibiotics prevent the growth of bacteria and kill bacteria
• antibiotics don`t destroy viruses like flu or cold. viruses reproduce using your body cells which makes it difficult to develop drugs that destroy just the virus without killing the bodies cells
• antibiotics has greatly reduced the number of deaths from communicable diseases caused by bacteria
• bacteria can become resistant to antibiotics
• bacteria can mutate this causes them to be resistant to an antibiotics
• if you have an infection some of the bacteria might be resistant to antibiotics
• when you treat the infection only non resistant strains of bacteria will be killed
• the individual resistant bacteria will survive and reproduce and the population of the resistant will increase
• the resistant strain could cause a serious infection that can`t be treated by antiobiotics
• the most powerful antibiotics is METICILLIN
• many drugs come from plants like aspirin is used as a painkiller to lower fever it was developed from willow, digitalis is used to treat heart conditions it comes from foxgloves
• some drugs came from microorganisms like peniciln
• drug testing

  A) humans

  B) whole or multiple

  C) live animal

  D) efficacy

  E) toxicity

  F) dosage

  G) passes

  H) clinical trial

  I) healthy

  J) optimum dosage

  K) most effective

  L) randomly

  M) placebo effect

  N) double blind