B3

• What are communicable diseases?

  Communicable diseases are diseases that can be spread from person to person.
• What are some examples of communicable diseases?

  Measles and Malaria are examples of communicable diseases.
• What are pathogens?


  Pathogens are microorganisms that cause infectious diseases.

  
• What are the 4 types of pathogens?

  The 4 types of pathogens are:

  - Viruses

  - Protists

  - Bacteria

  - Fungi

  
• How do bacteria cause illness?

  Bacteria reproduces very rapidly and release toxins which damage tissues and make us feel ill.

  
• What is the difference between viruses and bacteria?

  Viruses cannot reproduce by themselves, they need a host cell to reproduce. Bacteria reproduce by themselves.
• How does a virus cause illness?

  Virus invades the host cell and reproduce rapidly causing cell damage (leading to cell bursting).

  
• How do pathogen spread?

  Pathogens can spread by direct contact, by water or by air.
• What is an example of pathogens spreading by air?


  Influenza

  
• What is an example of pathogens spreading by water?

  Cholera

  
• What is an example of pathogen spreading by direct contact?

  HIV

  
• How do we reduce the spread of pathogens?

  We can reduce the spread of pathogens by:

  - Washing hands before eating

  - Providing people with clean drinking water (UK water has chlorine which kill microbes)

  - Using condoms to reduce the spread of HIV

  - Isolation of patients

  - Vaccination
• Can viruses be killed by antibiotics?

  No, only bacteria can be killed by antibiotics.
• What are symptoms of measles?

  Symptoms of measles include:

  - Fever

  - Red Rash

  
• How is measles spread?

  Measles are spread from droplets when an infected person coughs or sneezes and another person inhales it.
• What can measles cause?

  Damage to the breathing system and brain, in several cases measles can be fatal.
• What is done to young children to prevent measles?

  Young children are vaccinated to prevent measles.

  
• What is a symptom of HIV?


  HIV causes a flu-like illness, where the virus attacks the cells of the patients immune system causing it to damage.
• What happens at late stage HIV?

  At late stage HIV, the immune system becomes badly damaged making it unable to deal with other infections/cancers.
• How can HIV be controlled?

  HIV can be controlled using antiretroviral drugs which stops the virus from multiplying inside so that the virus cannot damage the immune system.

  
• What is a negative of using antiretroviral drugs?

  Antiretroviral drugs does not cure HIV or AIDS, the patient must remember to take the drugs for the rest of their life.
• How can HIV be spread?

  HIV is spread by sexual contact or exchange in body fluids through needles.

  
• What is TMV?


  Tobacco mosaic virus is a widespread plant pathogen which causes discolouration of leaves and affects growth of a plant due to a lack of photosynthesis.

  
• What are two types of bacterial diseases?

  Two types of bacterial diseases include:

  - Gonorrhoea

  - Salmonella
• How can bacteria be treated?

  Bacteria can be treated using antibiotics.
• What causes salmonella?


  Salmonella is caused by bacteria ingested in food and food prepared in unhygienic conditions.

  
• What are some symptoms of salmonella?

  Symptoms of salmonella include:

  - Fever

  - Cramps

  - Vomiting

  - Diarrhoea
• What is done to poultry in the UK to control salmonella spread?

  Poultry (e.g chickens) are vaccinated against salmonella to stop the spread of the disease.
• What is gonorrhoea?


  Gonorrhoea is a sexually transmitted disease (STD) which is spread by sexual contact.
• How can the spread of gonorrhoea be controlled?

  The spread can be controlled by treatment with antibiotics or the use of a barrier method of contraception such as a condom.
• How was gonorrhoea originally treated?

  It is caused by a bacterium and was easily treated with the antibiotic penicillin until many resistant strains appeared.
• What are the symptoms of gonorrhoea?

  -Thick yellow or green discharge

  -Pain when urinating
• What is an example of a fungal disease?

  An example of a fungal disease is rose black spot.
• What is rose black spot?

  A fungal disease where purple or black spots develop on leaves causing them to turn yellow and drop early.

  
• Why is rose black spot bad for the plant?

  Rose black spot affects the growth of the plant as photosynthesis is reduced.
• How is rose black spot spread?

  Rose black spot is spread by water and wind.
• How can rose black spot be treated?

  Rose black spot can be treated using fungicides or removing affected leaves.
• What is an example of a protist disease?


  Malaria is an example of a protist disease.
• What are symptoms of malaria?

  Symptoms of malaria include:

  - Repeated episodes of fever
• What is the cycle of malaria?

  1) A person infected with malaria is bitten by a mosquito.

  2) The mosquito has the malaria pathogen.

  3) The mosquito bites another person and passes the malaria pathogen to them.