Communicable disease

• What are pathogens?


  Microorganisms that cause diseases which spread between organisms
• What are the key components of infectious diseases?


  • Disease
  • Pathogen
  • How it's spread
  • Symptoms
  • Prevention / treatment
• What is the pathogen that causes Rose black spot?


  • Pathogen: Fungus
  • Spread by: Water and wind
  • Symptoms: Purple/black spots on leaves, can turn yellow and drop off
  • Prevention/Treatment: Removing and destroying infected leaves, fungicides, reduced growth
• What is the pathogen that causes Malaria?


  • Pathogen: Protist
  • Spread by: Mosquito vectors
  • Symptoms: Fever, can be fatal
  • Prevention/Treatment: Mosquito nets, stop mosquitoes from breeding
• What is the pathogen that causes Salmonella food poisoning?


  • Pathogen: Bacterium
  • Spread by: Eating contaminated food
  • Symptoms: Fever, stomach cramps, vomiting, diarrhoea
  • Prevention/Treatment: Vaccination of poultry, hygienic food preparation
• What is the pathogen that causes Gonorrhoea?


  • Pathogen: Bacterium
  • Spread by: Sexual contact
  • Symptoms: Pain when urinating, yellow/green discharge from vagina or penis
  • Prevention/Treatment: Condoms, antibiotics
• What is the pathogen that causes Measles?


  • Pathogen: Virus
  • Spread by: Airborne droplets (coughs and sneezes)
  • Symptoms: Fever, red skin rash, can be fatal
  • Prevention/Treatment: Vaccination of children
• What is the pathogen that causes HIV?


  • Pathogen: Virus
  • Spread by: Sexual contact, exchanging bodily fluids (e.g. blood)
  • Symptoms: Flu-like (initially), a damaged immune system (late stage infection/AIDS)
  • Prevention/Treatment: Condoms, avoid sharing needles, antiretrovirals
• What is the pathogen that causes Tobacco mosaic virus (TMV)?


  • Pathogen: Virus
  • Spread by: Direct contact between plants (not required to learn)
  • Symptoms: Mosaic pattern on leaves, which reduces photosynthesis and growth
  • Prevention/Treatment: Not required to know
• Why is it important to remove and destroy infected leaves in the case of Rose black spot?


  To prevent the spread of the fungus and reduce growth
• How do the symptoms of Malaria differ from those of Salmonella food poisoning?


  Malaria causes fever, while Salmonella causes fever, stomach cramps, vomiting, and diarrhoea
• What preventive measure can be taken to avoid the spread of Gonorrhoea?


  Using condoms during sexual contact
• What is the significance of vaccination in preventing diseases like Measles and Salmonella?


  Vaccination helps to prevent the spread of these diseases by building immunity
• What are the symptoms of HIV in its late stage?


  A damaged immune system (late stage infection/AIDS)
• How does the transmission of HIV differ from that of Measles?


  HIV is transmitted through sexual contact and bodily fluids, while Measles is airborne
• Why is it not necessary to learn how TMV is prevented?


  Because the prevention methods are not specified in the study material
• What are pathogens?


  Microorganisms that enter your body and cause disease
• How can pathogens affect different organisms?


  They can infect many different parts of the body and spread diseases
• Can both plants and animals be infected by pathogens?


  Yes, both can be infected by pathogens
• How small are bacteria compared to body cells?


  Bacteria are about 1/1000th the size of body cells
• How do bacteria make you feel ill?


  By producing toxins that damage your cells and tissues
• What are viruses not classified as?


  Viruses are not cells
• How do viruses compare in size to bacteria?


  Viruses are about 1/100th the size of a bacterium
• How do viruses replicate inside the body?


  They use the cells' machinery to produce many copies of themselves
• What happens to the cell after a virus replicates inside it?


  The cell usually bursts, releasing new viruses
• What causes you to feel ill when infected by a virus?


  The damage caused to the cells by the virus
• What type of organisms are protists?


  Single-celled eukaryotes
• How do some protists cause damage to other organisms?


  As parasites that live on or inside other organisms
• How are protists often transferred to other organisms?


  By a vector that does not get the disease itself
• What are fungi made up of?


  Some are single-celled, while others have a body made of hyphae
• How can hyphae affect the human body and plants?


  They can invade the body and cause diseases
• What can hyphae produce that spreads to other organisms?


  Spores that can be spread to other plants and animals
• What are the main ways pathogens can be spread?


  • Water: Contaminated drinking water (e.g., cholera)
  • Air: Airborne pathogens from coughs or sneezes (e.g., influenza)
  • Direct Contact: Touching contaminated surfaces (e.g., ringworm)
• How can bacterial infections be spread through water?


  By drinking water contaminated with the diarrhoea of other sufferers
• How are airborne pathogens transmitted?


  They are carried in droplets produced when you cough or sneeze
• How can pathogens be picked up through direct contact?


  By touching contaminated surfaces, including skin
• What is ringworm?


  A fungus that makes skin itch and flake off
• What is the significance of vectors in the transmission of protists?


  Vectors transfer protists to organisms without getting the disease themselves
• What are the three types of diseases mentioned that are caused by viruses, fungi, and protists?

  Measles, HIV, and malaria
• What is the question asked in Q1 regarding viruses?


  Describe how viruses cause cell damage