Module 4.1.1 - Communicable Diseases, Disease Prevention & The Immune System Flashcards
What is a gram positive bacteria?
Looks purple/blue under light microscope
Stained with crystal violet
What is an example of a gram positive bacteria?
MRSA
What is gram negative bacteria?
Looks red under a light microscope
Stained with safranin
What is an example of a gram negative bacteria?
E.coli
What are the 4 different shapes of bacteria?
Cocci (spherical)
Vibrio (curved)
Bacilli (rod-shaped)
Spirilli (spiral)
What are the problems with bacteria reproducing so quickly?
Food spoilage & spread of disease
How do bacteria cause disease?
Release toxins (from antigens on bacteria)
- cause symptoms by cell damage
- damage cell membranes/enzymes or genetic material
What are some examples of bacterial diseases and what bacteria causes them?
Tuberculosis - Mycobacterium Turberculosis
Bacterial meningitis - Streptococcus Pnuemoniae
Ring rot - (gram positive) Clavibacter Michiganesis
What is the structure of a bacteriophage?
Protein coat
Loose genetic material
Tail plate
Injection tube
What are the stages of bacteriophages invading living cells?
1) virus attaches itself to specific host cell
2) the genetic material from the virus is injected into the host cell
3) the viral genes cause the host cell to make new viruses
4) the host cell splits open, releasing the new virus
What are some examples of viral diseases?
HIV/AIDS - Human Immunodeficiency Virus
Influenza - orthomyxoviridae spp.
Tobacco Mosaic virus
What is the structure of a fungi?
Cell wall
Nucleus
Cell membrane
Cytoplasm
Vacuole
Mitochondria
How do fungi reproduce?
Asexually - by budding
What are some examples of fungal diseases?
Cattle ringworm - Trichophyton Verrucosum
Athlete’s foot - Tinia Pedia
Black Sigatoka - Mycosphaerella Fljensis
What is the structure of protoctists?
Unicellular
Nucleus
What are some examples of protozoan diseases?
Blight in potatoes/tomatoes - Protoctist Ommycete
Malaria - Plasmodium
What are the direct ways of transmission between animals?
Direct contact (transmission through bodily fluids)
Inoculation (break in the skin - animal bite/puncture wound/sharing needles)
Ingestion (taking in contaminated food or drink/transferring pathogens from hand to mouth)
What are the indirect ways of transmission between animals
Fomites (inanimate objectes)
Droplet infection (breathing in saliva/mucus from the air that is expelled from someone when sneezing/coughing)
Vectors (e.g. mosquitoes for malaria)
What are the factors that increase the transmission of communicable diseases in animals?
Over population
Poor disposal of waste
Malnutrition
Globalisation
Infrastructure
Climate change
Invasive species
Culture
Access to healthcare
Socioeconomic factors
What are the ways of direct transmission in plants?
Direct contact (Healthy plant touches any part of an infected plant)
What are the ways of indirect transmission in plants?
Soil contamination (infected plants offer pathogens in the soil which can affect the next crop)
Vectors (e.g. wind/water/animals/humans)
What are the factors that increase the transmission of communicable diseases in plants?
Climate change
Overcrowding
Damp & warm conditions
Poor soil/mineral nutrition
Plant varieties susceptible to disease
What are the physical defences of plants against pathogens?
Cellulose cell wall - physical barrier, lignin thickening cell walls (waterproof & ingestible)
Waxy cuticle - prevents water collecting on the surface (pathogens need water)
Guard cells - close stomata
Callose - large polysaccharide deposited into sieve tubes at the end of the growing season (blows flow so pathogens can’t spread)
What are the chemical defences of plants against pathogens?
Terpenoids - antibacterial & antifungal properties (some create a scent)
Alkaloids - nitrogen compounds with a bitter taste (e.g. caffeine/nicotine/cocaine/morphine), stops herbivores feeding on them - less grazing = less exposure
What is active immunity?
Happens when you have a cellular response e.g. T&B cells & antibodies
What is Natural Active immunity?
Happens when a pathogens enters your body - cellular response