P1: Biology- Infection and Response

• What is a pathogen?

  Microorganisms that cause infectious diseases
• What can pathogens infect?

  Plants or animals
• How can pathogens be spread?

  -Direct contact

  -Water or air

  -Vectors
• What is a vector?

  An organism which carry and pass on the pathogen without becoming infected by the disease
• How can the spread of disease be reduced?

  -Hygiene measures

  -Destroying vectors

  -Isolating infected individuals

  -Giving people at risk vaccines
• How do viruses damage cells?

  As they reproduce rapidly within the cells
• What is measles caused by?


  Virus
• Symptoms of measles?

  -Fever

  -Red skin rash
• How is measles spread?

  By breathing in droplets from sneezes and coughs
• Is there a vaccine/cure for measles

  Vaccine
• What does HIV cause?

  AIDS
• How is HIV spread?

  -Sexual contact

  -Exchange of bodily fluids

  -Sharing needles
• Symptoms of HIV:

  -Flu-like symptoms
• What does HIV do to the body?

  Enters the lymph nodes and attacks the body immune system
• What is AIDS?

  Late stage HIV, where the body can no longer fight of infection or cancers
• There a vaccine/cure for HIV

  No, but antiviral drugs can delay the affects
• How do bacterial diseases damage cells?

  Directly, or may produce toxins which damage tissues
• What is salmonella caused by?

  Bacteria
• What gives a person salmonella?

  If the bacteria is ingested in food, which has not been cooked properly or not prepared in hygienic conditions
• Symptoms of salmonella:

  -Fever

  -Abdominal pain

  -Vomiting

  -Diarrhoea
• How is the spread of salmonella controlled?

  By vaccinating chickens against salmonella
• What is gonorrhoea caused by?

  Bacteria
• How is gonorrhoea spread?

  By sexual contact
• Symptoms of gonorrhoea:

  -Thick, yellow or green discharge from the vagina or penis

  -Pain when urinating
• Is there treatment for gonorrhoea?

  Can be treated with penicillin, but many resistant strains have appeared
• How to control the spread of gonorrhoea?

  Barrier methods of contraception eg. condoms
• What is a protist?

  Single celled organisms
• What type of cell is a protist?

  Eukaryotic
• What is malaria caused by?

  A protist
• What does malaria use as a vector?

  Mosquitos
• How is malaria spread?

  When a person is bitten by a mosquito which carries the malaria protist
• Symptoms of malaria?

  Severe fever
• How to control the spread of malaria?

  Stopping people being bitten by mosquitos eg. killing mosquitos or mosquito nets
• What is rose black spot caused by?

  Fungus
• How is rose black spot spread?

  By spores being carried from plant to plant by the wind or water
• Symptoms of rose black spot:

  -Purple or black spots appear on leaves, which may turn yellow and drop early
• How does rose black spot affect the plant?

  -The loss of leaves will cause stunted growth as photosynthesis is reduced
• How can rose black spot be treated?

  Using fungicides and removing and destroying affected leaves
• What is a non-specific defence?

  Defences that work against all pathogens to try stop them from entering the body
• Body defences in the throat :

  Mucus: traps particles and bacteria

  Cilia: sweeps mucus along