Communicable Diseases

• Define 'Communicable Disease'


  A disease that can be passed from one person to another person

  Caused by pathogens
• Define 'Micro-organism'


  Single celled organisms that can only be views using a microscope
• Define 'Pathogen'


  A micro-organism that causes a disease
• Define 'Health'


  A state of physical and mental well-being and an absence of a disease
• How can your diet affect your health


  If you do not eat enough

  Incorrect nutrients

  It can lead to problems such as obesity, some cancers and type 2 diabetes
• What life situations effect your health?


  The area of the world you live

  Your gender

  Your financial status

  The levels of free health-care provided
• Examples of bacteria related diseases


  Tuberculosis, cholera, food poisoning, impetigo
• Examples of virus related diseases


  Measles, chickenpox, AIDS, common cold, covid-19
• Examples of fungi related diseases

  Athletes foot
• Example of a protoctista related disease

  malaria
• Example of useful bacteria


  Used to make yogurt and cheese

  Treats sewage

  For genetic engineering
• Example of useful fungi


  Used to make bread/alcohol

  Penecillin
• Key features of a bacteria


  Unicellular, microscopic, no nucleus, plasmatic membrane
• How do bacteria cause disease

  They give off chemicals calls toxins which can damage tissue and make you sick
• Key features of a fungi


  Eukaryotic, non-vascular, non-motile, heterotropic organisms
• How do fungi cause disease


  When fungi accidentally penetrate host barriers, or when immunologic conditions exist that favour fungi entry and growth
• Key features of a virus


  Small, have DNA or LNA genomes, obligate intracellular parasites
• How do viruses cause disease?

  By killing important cells or disrupting cell function
• Key features of a protist


  Eukaryotic, have mitochondria, they can be parasites, aquatic, unicellular
• How do protists cause disease?

  Feed off another organism causing harm
• How can diseases be transmitted in animals?


  Air (including droplet infections), direct contact, water, contaminated food, insect vectors, cuts/blood, sexual intercourse
• Symptoms/Transmission/Treatment of measles


  -Fever and skin rash

  -The virus is spread by inhalation of droplets from coughing and sneezing

  -Isolation
• Symptoms/Transmission/Treatment of HIV


  -Mild flu like illness to begin with, then remains hidden in the immune system

  -Spread by direct sexual contact and exchange of bodily fluids

  -vaccination
• Symptoms/Transmission/Treatment of Tobacco Mosaic Virus


  -Causes a distinctive 'mosaic' pattern of discolouration on the leaves. This leads to lack of growth

  -By contact between plant material which is diseased and healthy plants

  -There is no treatment
• Symptoms/Transmission/Treatment of Salmonella


  -Fever, abdominal cramps and vomiting

  -Bacteria that lives in the guts of animals, found in raw meat

  -Vaccination
• Symptoms/Transmission/Treatment of Gonorrhoea


  -In the early stages, yellow or green discharge, pain during urination

  -Unprotected sex

  -Antibiotics
• Symptoms/Transmission/Treatment of Rose Black Spot


  -Purple or black spots develop on the leaves. They often turn yellow or drop early

  -Spores of fungus spread in the environment carried by wind

  -Removing and burning affected leaves
• Symptoms/Transmission/Treatment of Malaria


  -Affects the liver and red blood cells. Recurrent episodes of shaking. Can be fatal

  -Female mosquito, who bites one human and then another

  -Drugs
• Define 'Immune System'


  A complex network of organs cells and proteins that defends the body against infection
• Define 'Antibody'


  A blood protein produced in response to and counteracting a specific antigen
• Define 'Antitoxin'


  An antibody that counteracts a toxin
• Define 'Phagocytosis' 


  The ingestion of bacteria or other material by phagocytes and amoeboid protozoans
• What is the functioning order of the immune system?


  Pathogens enter the blood-steam > Lymphocytes produces antibodies/antitoxins > Antibodies bind to antigens on pathogens > Phagocytes of pathogens or toxins
• What happens if blood doesn't clot properly?


  Scabs wont form as quickly, easier for pathogens to get in through the cut
• Explain the function of antibodies and antitoxins


  They bind to pathogens and clump them together to stop them getting into cells
• Explain the function of memory cells


  Left in your bloodstream after a vaccination or infection. They cause a quicker immune response and produce lots of antibodies.
• What is the primary immune response

  The first time the immune system encounters a pathogen
• What is the secondary immune response?


  The second time the immune system encounters a pathogen
• Why will antibodies be produced quicker if the same bacteria infect the body again?

  Because of memory cells recognising the pathogen
• What is a vaccination


  An injection of dead or weakened pathogens or antigens of the pathogens