Chapter 5: Communicable Diseases

Created by

Eva Skidmore

Cards (54)

What is a communicable disease?
a disease that can be transmitted from one organism to another
What is a pathogen?
a microorganism that causes disease
Name four types of pathogen.
bacteria, fungi, protists, viruses
How can pathogens spread?
air
direct contact
vectors
blood contact
contaminated food & water
How do bacteria make you ill?
produce toxins that damage tissues
How do viruses make you ill?
reproduce rapidly inside cells, damaging or destroying them
Name three examples of viral diseases.
measles, HIV, tobacco mosaic virus
Name two examples of bacterial diseases.
Salmonella, gonorrhoea
Name four methods of controlling the spread of communicable disease.
good hygiene, isolating infected individuals, controlling vectors, vaccination
Describe an example of a protist disease. 
malaria – caused by a protist pathogen that is spread from person to person by mosquito bites, and causes recurrent fevers
Describe an example of a fungal disease in plants.
rose black spot – affects plant growth by reducing a plant’s ability to photosynthesise
How can the cause of a plant disease be identified?
gardening manuals and websites, laboratory testing, monoclonal antibody kits
What are three mechanical defences that protect plants?
thorns and hairs, leaves that droop or curl, mimicry to trick animals
Give three physical defences of plants.
cellulose cell walls, tough waxy cuticles, bark on trees
How can aphids be controlled by gardeners?
introduce ladybirds to eat the aphids
How can plant diseases be detected?
areas of decay, discolouration, growths, malformed stems or leaves, presence of pests, spots on leaves, and stunted growth
How is Rose Black Spot Spread?
Through wind & water droplets
How are measles spread?
Through respiratory droplets.
What are some symptoms of measles?
Fever
Rash
Possible fatal complications
How is HIV spread?
Sexual contact or exchange of bodily fluids (Sharing needles when using drugs)
What are some symptoms of HIV?
Flu-like symptoms
Virus attacks body's immune cells --> AIDS
How is Tobacco Mosaic Virus spread?
Direct contact of plants with infected plant material
Animal & Plant Vectors
Soil
What are some symptoms of Tobacco Mosaic Virus
Mosaic pattern of discolouration on the leaves (chlorophyll destroyed)
Reduces plant's ability to photosynthesise
Stunted growth
How is Salmonella spread?
Bacteria in or on food that is being ingested
What are some symptoms of Salmonella ?
Fever
Abdominal Cramps
Vomitting
Diarrhoea
How do you prevent Salmonella?
Vaccinate poultry against salmonella bacteria
How is Gonorrhoea spread?
Sexual Contact (STD)
What are some symptoms of Gonorrhoea? 
Thick yellow or green discharge from the vagina or penis
Pain when urinating
How do you treat Gonorrhoea? 
Antibiotics
How do you prevent Gonorrhoea? 
Barrier methods of contraception (E.g. condoms)
How do you treat Rose Black Spot?
Fungicides (chemicals)
Remove & Destroy affected leaves
What are some Fungal Diseases?
Athlete's foot, ringworm & rose black spot
How is Athlete's Foot Spread?
Direct Contact
What are some symptoms of Athlete's Foot? 
Sore, red, flaky skin
Itchy white patches
How is Ringworm spread?
Direct Contact
What are some symptoms of ringworm?
Red/Silver Rash
Dry, itchy, swollen skin
What is MKSA? 
A type of bacterium resistant to many antibiotics
How do vaccinations work?
Introduces small quantities of pathogen into the body (dead or inactive pathogen)
Stimulates white blood cells to produce antibodies
White Blood Cells will respond faster if a pathogen enters the body
What are the stages of Phagocytosis?
Macrophage (Type of white blood cell)
Macrophage engulfs bacteria
Digestive enzyme is secreted into the vesticle to digest bacteria
Digested bacteria gets absorbed by the cytoplasm
How do Antibodies work?
Lymphocyte's antibodies will bind to the antigens on the pathogen.
Pathogen is engulfed and digested by the macrophage
Pathogen bursts (dies)