4.1 Communicable diseases Flashcards
Name the 4 types of pathogens-
Bacteria, viruses, fungi and protoctista
What is a communicable disease?
A disease that is caused by a pathogen and transmitted directly between organisms
Bacteria definition-
Prokaryotic cells that have cell walls but lack organelles. Some bacteria are
pathogenic, producing toxins that damage host cells
2 ways bacteria can be classified-
By their basic shapes, by their cell walls
Virus definition-
Non-living infectious agents that invade host cells and take over cell metabolism,
replicating within them
Protoctista definition-
A group of eukaryotic, single-celled microorganisms that may cause disease.
They digest cells and use the cell contents to reproduce
Fungi definition-
Eukaryotic, often multicellular organisms that may cause disease. They digest and
destroy cells, and produce spores that can spread rapidly between organisms
Name the 4 plant diseases-
Ring rot, Tobacco mosaic virus, Potato/ tomato late blight, Black sigatoka
What does ring rot infect?
Potatoes, tomatoes, aubergines
What pathogen causes ring rot?
Bacteria (gram positive)
How does ring rot bacteria damage plants?
Bacteria infects the vascular tissue and prevents the transport of water. It spreads into tubers where vascular tissue is arranged in a ring. It also damages fruit and leaves
Is there a cure for ring rot?
There is no cure and once bacterial ring rot infects a field, it cannot be used to grow crops again for at least two years.
What does tobacco mosaic virus infect?
Tobacco plants and around 150 other species e.g. tomatoes, peppers, cucumbers, petunias
What pathogen causes tobacco mosaic virus?
Virus
How does tobacco mosaic virus damage plants?
It damages the leaves, flower and fruit. It causes a distinct yellowing of leaves which produces a mosaic pattern, and stunts growth
Is there a cure for tobacco mosaic virus?
There is no cure but resistant crop strains are available
What does potato blight damage?
Tomatoes and potatoes
What pathogen causes potato blight?
Fungus-like protoctist
How does potato blight damage plants?
Hyphae penetrate host cells and damage leaves, tubers and fruit
Is there a cure for potato blight?
No cure but resistant crop strains are available
What does black sigatoka infect?
Banana plants
What pathogen causes black sigatoka?
Fungus
How does black sigatoka damage plants?
Hyphae penetrate and digest cells turning the leaves black
Is there a cure for black sigatoka?
No cure but resistant crop strains are being developed
How is ring rot transmitted?
Direct contact of seed potato tubers, sharing equiptment, soil contamination
How is ring rot treated/ prevented?
Spacing harvest, good field hygiene, not using field for 2 years after infection
How is tobacco mosaic virsus transmitted?
Direct contact between leaves, contaminated tools/ workers hands
How is tobacco mosaic virus treated/ prevented?
Remove diseased plants, good field hygiene, crop rotation
How is potato blight transmitted?
Spores carried by wind/ water
How is potato blight treated/ prevented?
Chemical treatment, careful management, spacing harvest
How is black sigatoka transmitted?
Spores carried by wind/ water
How is black sigatoka treated/ prevented?
Use of fungicide, remove infected leaves
What does tuberculosis infect?
Humans, badgers, cows, pigs, deer
What pathogen causes tuberculosis?
Bacteria
What damage does tuberculosis cause?
Damages lung tissue and suppresses immune system so more susceptible to other diseases. Causes chronic cough and bloody mucus
Is there a cure for tuberculosis?
Curable using antibiotics
What does bacterial meningitis infect?
Humans, usually very young children and teenagers
What pathogen causes bacterial meningitis?
Bacteria
What damage does bacterial meningitis cause?
Damages meninges of the brain which can spread to the body to cause septicaemia
Is there a cure for bacterial meningitis?
Curable using antibiotics
What does influenza infect?
Humans, birds, pigs
What pathogen causes influenza?
Virus
What damage does influenza cause?
Kills ciliated epithilial cells in respiratory system, leaving airways open to secondary infection
Is there a cure for influenza?
No cure although vulnerable groups are given flu vaccine in attempt to protect against new strains
What does ring worm infect?
Mammals including humans, cattle, cats, dogs
What pathogen causes ring worm?
Fungus
What damage does ring worm cause?
Not overly damaging but may be itchy. Causes grey- white, crusty, infectious areas of skin
Is there a cure for ring worm?
Antifungal creams
What does athletes foot infect?
Humans
What pathogen causes athletes foot?
Fungus
What damage does athletes foot cause?
Grows on and digests warm, moist skin between the toes
Is there a cure for athletes foot?
Antifungal creams
What does HIV infect?
Humans
What pathogen causes HIV?
Virus
What damage does HIV cause?
Targets T helper cells in immune system and gradually destroys immune system so affected people are open to other infections
Is there a cure for HIV?
No cure but antiretrovial drugs slow the progress of the disease
What does malaria infect?
Humans
What pathogen causes malaria?
Protoctist
What damage does malaria cause?
Destroys red blood cells in the liver and brain. Causes fever, fatigue, chills
Is there a cure for malaria?
No vaccine and limited cures
How is tuberculosis transmitted?
Droplets (coughs and sneezes)
How is tuberculosis treated/ prevented?
Improving living standards, vaccines
How is bacterial meningitis transmitted?
Droplets (coughs and sneezes), very close contact e.g. kissing
How is bacterial meningitis treated/ prevented?
Vaccines
How is influenza transmitted?
Droplets (coughs and sneezes), hands touching infected surface and then touching face
How is influenza treated/ prevented?
Vaccines, wash hands
How is ring worm transmitted?
Direct contact with infected person or contaminated surfaces
How is ring worm treated/ prevented?
Avoid contact with infected people
How is athletes foot transmitted?
Direct contact with infected person or contaminated surfaces
How is athletes foot treated/ prevented?
Keep feet clean and dry, wear shoes in areas where infected feet have been
How is HIV transmitted?
Exchange of bodily fluids
How is HIV treated/ prevented?
Condoms, don’t share needles
How is malaria transmitted?
Bites of infected mosquitos, sexually in mosquitos
How is malaria treated/ prevented?
Control vector e.g. insecticides, remove standing water where they breed, mosquito nets, window+door screen, long sleeved clothing
