B3-Infection and Response

• What are pathogens?

  Microorganisms that enter the body and cause disease
• What do bacteria produce?

  Toxins that damage your cells and tissues
• What can bacteria do?

  Reproduce rapidly inside the body
• What can viruses do?

  Reproduce rapidly inside the body and replicate themselves in the cell to produce many copies of themselves

  The cell bursts releasing all the viruses
• What are protists?

  Single celled eukaryotes
• What is a vector?

  Transfers the parasites to other organisms but doesn’t get the disease itself
• How can pathogens be spread ?

  Through water (drinking or bathing in dirty water)

  Through air (droplets produced by cough or sneeze)

  Direct contact by touching contaminated surfaces
• What disease is measles?

  Viral and spread by droplets from sneezing and coughing
• Symptoms of measles?

  Red rash

  Fever
• What type of disease is HIV?

  Virus spread by sexual contact or by sharing needles
• Symptoms of HIV?

  Flu like symptoms
• How can HIV be controlled?

  Antiretroviral drugs
• What does HIV do?

  attacks immune cells so the immune system is damaged and can’t deal with other infections or cancers
• What type of disease is Tobacco mosaic virus?

  Virus in plants
• Symptoms of tobacco mosaic virus?

  Discoloured leaves and mosaic patterns
• What does tobacco mosaic virus do?

  Photosynthesis can’t happen as well so growth is limited
• What type of disease is Rose Black Spot?

  Fungus spread through water or wind
• Symptoms of black rose spot?

  Purple or black spots on leaves

  Leaves can turn yellow and drop off
• How to treat rose black spot?

  Fungicides and destroy affected leaves
• What is malaria caused by?

  Protist
• What is the vector for malaria?

  Mosquito
• What does malaria cause?

  Repeated fevers
• How can people be protected by mosquitos?

  Insecticides and mosquito nets
• What bacteria causes food poisoning?

  Salmonella
• What are symptoms of salmonella?

  Fever

  Stomach cramps

  Vomitting

  Diarrhoea
• How can you get salmonella?

  Eating contaminated food
• How are people protected against salmonella?

  Most poultry is vaccinated against Salmonella to control the spread of the disease
• What bacteria is a sexually transmitted disease?

  Gonorrhoea
• How are STDs passed on?

  Sexual contact
• Symptoms of gonorrhoea?

  Painful urination

  Thick yellow green discharge
• How can gonorrhoea be treated?

  Antibiotics

  Barrier methods of contraception (condoms)
• How can the spread of disease be prevented?

  Being hygienic

  Destroying vectors

  Isolating infected individuals

  Vaccination
• What is a barrier to pathogens?

  Skin
• How is the nose a defence system?

  Hair and mucus in the nose trap particles containing the pathogen
• How does the trachea and bronchi trap pathogens?

  Secretes mucus
• What does the trachea and bronchi have to do this?

  Lined with cilia which waft the mucus up to the throat where it is swallowed
• How does the stomach kill pathogens?

  Produces hydrochloric acid
• What is the first line of attack for white blood cells?

  -Phagocytosis

  White blood cells engulf foreign cells and digest them
• What is the second line of attack for white blood cells?

  -Produce antibodies

  When white blood cells see foreign cells they produce antibodies specific to the antigen to lock onto the invading cells so they can be destroyed by other white blood cells

  Antibodies are produced rapidly to kill other bacteria

  Creates memory cells so becomes naturally immune to the pathogen and won’t get ill again
• What is the third line of attack for white blood cells?

  -Produces antitoxins

  Counteract the toxins produced by invading bacteria