12.2 Animal and Plant Diseases Flashcards
What type of disease is Ring rot ?
Bacterial
What plants does ring rot affect ?
Potatoes, tomatoes and aubergines
What is ring rot caused by ?
Gram positive bacterium
What is the cure for ring rot ?
No cure discovered yet
What does ring rot damage ?
Leaves , tubers and fruit
What happens to a field once it has been infected by Ring Rot ?
cannot be used to grow potatoes, tomatoes or aubergines for at least two years
What type of pathogen causes ring rot ?
A bacterium
What type of disease is TMV ?
Virus
What does TMV infect ?
Tobacco plants and 150 other species
How is TMV prevented and cured ?
- resistant crop strains can prevent it
- there is no cure
What is the mechanism of TMV ?
- damages leaves, flowers and fruit
- stunting growth and reducing yield
- leads to almost total crop loss
What is potato blight caused by ?
A fungus like protoctistia called oomycete
How is potato blight prevented and cured ?
- no cure
- can be prevented via use of resistant strains
- careful management and chemical treatments
What is the mechanism of potato late blight ?
- hyphae penetrate host cells and destroy leaves, tubers and fruit
- leading to millions of pounds of crop damage per year
What type of pathogen causes black Sigatoka ?
Fungus
What type of plant does black Sigatoka affect ?
Bananas
What part of the plant does black Sigatoka affect ?
The leaves
What is the mechanism of black Sigatoka ?
- hyphae penetrate and digest cells
- turning leaves black
- can cause 50% reduction in yield of infected plants
How is black Sigatoka cured and prevented ?
- no cure
- resistant strains being developed and good husbandry and fungicide treatment can control the spread of the disease
What organisms does tuberculosis affect ?
Humans, cows ,pigs, badgers and deer
What type of pathogen is tuberculosis caused by ?
Bacteria
Perplexed suffering from what other disease are more prone to TB ?
HIV/aids
How is TB cured and prevented ?
- cured with antibiotics
- prevented by vaccination or better living standards
How is TB spread in humans ?
Droplet infection
What is the mechanism of TB ?
- damages and destroys lung tissue and suppresses the immune system
- so that the body is less able to fight off other diseases
How is bacterial meningitis spread ?
By droplet infection
How is bacterial meningitis cured and prevented ?
- curable with antibiotics if administered early
- vaccination can protect against some forms
What are the mechanism and symptoms of bacterial meningitis ?
- infection of meninges ( protective membranes on brain surface ) which can spread to the rest of the body and cause fatal septicaemia
- symptoms include = blotchy red/ purple rash that does not disappear when a glass is pressed against it is a symptom and immediate medical treatment is required
Who are the main groups affected by bacterial meningitis ?
Young children and 15-19 year olds
What type of virus is HIV/AIDS ?
A retrovirus
What is the mechanism of the HIV virus ?
- attacks T helper cells
- which gradually destroys the immune system and leaves sufferers vulnerable to secondary infection
How does a retrovirus ?
- a virus that is composed of RNA not DNA
- retroviruses have an enzyme called reverse transcriptase that gives them the unique property of transcribing their RNA into DNA after entering a cell
- the retroviral DNA can then integrate into the chromosomal DNA of the host cell to be expressed there
What animals does HIV/ aids affect ?
Humans and some other primates
How is HIV spread ?
- passed between people via infected bodily fluids
- unprotected sex
- shared needles
- contaminated blood
- mother to baby through breastfeeding or pregnancy
What is FGM ?
- female genital mutilation*
- traditional practice
- increases the infection rate if the same equipment is used multiple times then this can spread the infection
- women who have undergone FGM are more vulnerable to infection during intercourse
How is HIV cured ?
- no vaccine or cure
- antiretroviral drugs can slow its progress
What animals does influenza affect ?
Mammals and birds
What is the mechanism of influenza ?
- infects ciliated epithelial cells in the gas exchange system
- killing them and leaving the airways vulnerable to secondary infections
- such as bacterial pneumonia
What are the 3 types of influenza and which is most virulent ?
A,B,C with A being most virulent
Why is a vaccine made each year for flu ?
- flu viruses undergo small regular mutations
- their surface antigens are constantly being reshuffled
Is there a cure for flu ?
No
What is zoonosis and give a example of something that it does ?
- where a disease can spread from animals to humans
- eg. Influenza
What age groups can the flu be fatal too ?
- young children
- old periphery with chronic illnesses
What cause Malaria ?
- several species of protoctista from the genus plasmodium
- most common being plasmodium falciparum
- it is spread by the bite of a female anopheles mosquito
What is the mechanism of Malaria ?
- infects red blood cells, liver , brain
- disease recurs making people weak and vulnerable to secondary infection
What is the cure for malaria ?
- no vaccine
- limited cures
What 2 reasons can make malaria difficult to treat ?
- protoctista hides inside red blood cells
- caused by several different species so surface antigens may be different
What are some preventive measures that can be taken ?
- anopheles mosquitoes can be destroyed by insecticides
- mosquitoes reproduce in areas of still water so you can drain these sites
- mosquitoes can be destroyed by insecticides
- mosquito nets
- window and door screens
- long sleeved clothing
What causes ring worm ?
Fungi
What mammals can ringworm affect ?
Cattle, dogs , cats and humans
What are the symptoms of ringworm ?
- grey - white crusty infections circular area of skin
- it is not damaging but looks unsightly and may be itchy
What is a cure for ring worm ?
Anti-fungal creams
What causes athlete foot ?
Human fungal disease caused by tinia Pedia
What is Tinia pedia ?
A form of human ring worm that grows on and digests the warm, moist skin between the toes
What does tinia pedia cause ?
- cracking & scaling
- can become itchy and sore
What is a cure for athletes foot ?
Anti-fungal creams
