Communicable diseases Flashcards
What is pathogen?
A microorganism that causes disease
What pathogen causes tuberculosis?
Bacteria
What pathogen causes ring rot (plants)?
Bacteria
What kingdom does bacteria belong to?
Prokaryote
How quickly can bacteria reproduce?
Every 20 mins
What does bacteria do to cells?
Damages them
How does bacteria damage cells?
It releases toxins
What part of the body does bacteria affect?
The lungs
What does ring rot cause?
leaf wilting
What pathogen causes balck sigatoka (plants)?
Fungus
What pathogen causes athlete’s foot?
Fungus
What is a mass of hyphae called?
fungus
Mycelium
What does reproductive hyphae release?
Spores
How does fungus digest plant tissue?
It releases extracellular enzymes (cellulase)
What pathogen causes HIV/AIDS?
Virus
What pathogen causes Influenza?
Virus
What pathogen causes tobacco mosaic virus (TMV)?
Virus
What is the name of viruses that infect bacteria?
Bacteriophage
How do viruses reproduce?
They take over cells and use them to make more copies of the virus. They then cause the cells to burst
What pathogen causes malaria?
Protoctista
What pathogen causes blight (potato and tomato)?
Protoctista
Why are protoctist referred to as parasites?
They feed on the host cell
Examples of direct transmission
animals
- Direct contact
- Inoculation
- Ingestion
Examples of direct contact
animals
- Bodily fluid contact
- Skin-to-skin
- Microbes from feces on hand
Examples of inoculation
animals
- Animal bite
- Break in skin
- Puncture wound
Examples of ingestion
animals
- Taking contaminated food
- mouth to hand pathogen transfer
Examples of in-direct transmission
animals
- Fomites (inanimate objects)
- Vectors (mosquitoes)
- Droplet infection (inhalation)
Factors that affect the spread of pathogens
animals
- Climate change
- Poor waste disposal
- Overcrowding
- Compromised immune system
Communicable diseases between humans and animals
- bird flu
- brucellosis
- foot-and-mouth
Examples of in-direct transmission
plants
- Soil contamination
- Wind
- Water
- Vectors (humans and animals)
Factors that affect the spread of pathogens
plants
- Climate change
- Overcrowding
- Damp, warm conditions
- Planting crop varieties susceptible to disease
Passive defences of plants
- Cellulose cell wall
- Lignin thickening of cell wall
- Waxy cuticle
- Stomatal closure
- Callose
- Tylose
What does callose do to defend the plant?
It deposits polysaccharides in to sieve tubes to prevent the spread of pathogens
What does tylose do to defend the plant?
It causes ballon like swelling to prevent the spread of pathogens
Chemical defences of plants
- Hydrolytic enzymes
- Insect repellents
- Toxins
- Insecticides
- Alkaloids
What does alkaloids do to defend the plant
It inhibits protein synthesis
Examples of hydrlytic enzymes
- Chitinase (chitin)
- Lysozymes (bacterial cell wall)
- Glucanase (Glucans)
Active defences in plants
- Additional cellulose to cell wall
- Increase in chem. prod.
- Deposition of callose
- Necrosis (cell suicide)
- Canker
Primary defences
How do the eyes defend against pathogens?
They contain antibodies and enzymes in tears
Primary defences
How do the ears defend against pathogens?
Wax in the ear blocks pathogens
Primary defences
Expulsive reflexes in reponse to pathogens
- Coughing
- Sneezing
- Vomiting
- Diarrohoea
Primary defences
Mucous membrane
DEFENCES
Cilliated cells
* moves mucus
Goblet cells
* secrets mucus
Primary defences
Lysozymes are found in:
ANIMAL
they destroy pathogens
- Urine
- Tears
- Stomach acid
Secondary non- specific defences
What are Opsonins?
A protein molecule that attach to antigens on the surface of the pathogen
It enhances the ability of phagocytic cells
Secondary non- specific defences
What are Antigens?
Protein markers on the outer membrane that specific to an organism.
They can also trigger an immune response when seen as foreign
Secondary non- specific defences
Phagocytes
Specialised wbc that engulf and digest pathogens (phagocytosis)
often made in the bone marrow
Secondary non- specific defences
What is the structure of neutrophils?
- Multi-lobed nucleus
- Granulated nucleus
- Large no. of lysosomes
