Animal and Plant Diseases

Question 1

Plant diseases

Answer 1

Ring Rot:

• Affects potatoes and tomatoes for example and it is caused by the gram pos. bacteria. It damages leaves, fruits and tubers and there is no cure.
• Once bacterial ring rot infects a field it cannot be used for at least 2 years.

Tobacco Mosaic Virus:
- Affects tobacco plants among 150 other species, damaging leaves, flowers and fruit, stunting growth and yield. There is no cure, but there are resistant crop strains.

Potato Blight - Protoctista:

• The hyphae (branching filaments of mycelium of fungus) penetrate host cells, destroying leaves, tubers and fruit. There is no cure but there are resistant crop strains.
• Careful management and chemical treatments reduces risk.

Black Sigatoka - Fungi:

• Attacks and destroys the leaves.
• Hyphae penetrate and destroy plant cells, causing the leaves to turn black unable to photosynthesis. No cure but fungicides and restraint strains can reduce chance of infection and spread.

Question 2

Animal diseases

Answer 2

Tuberculosis - bacteria:
- Affects humans, cows, pigs, badgers and deer. It damages lung tissue and suppresses the immune system. TB is curable with antibiotics and preventable with vaccination and good living conditions.

Bacterial Meningitis:
- Affects the meninges (protective membranes) of the brain, which can spread to the rest of the body causing septicaemia and death. Antibiotics can cure the disease if delivered early, and vaccinations protect against some strains.

HIV/AIDS:

• Immunodeficiency syndrome caused by human immunodeficiency virus.
• It gradually destroys the immune system.
• There is no cure or vaccination, but anti-retroviral drugs give years more life.

Influenza - virus:

• Kills the ciliated epithelial cells in the ventilation system, leaving the sufferer more susceptible to other diseases.
• It can be fatal to the very young, old, and chronically ill. It affects mammals and birds.
• Due to the frequent mutation of the flu virus, there is no vaccination or cure.

Malaria - Protoctista:
​​- Spread via the vector of Mosquito. The protoctist reproduces inside the mosquito, before being passed to humans when the mosquito bites.
- It invades the red blood cells, liver and brain; the disease then makes people weak to other infections.
- There is no vaccine and limited cures but preventative methods such as controlling the vector through insecticides and mosquito nets can prevent the spread.

Ringworm:
- Different fungi affect different species, causing grey, crusty, infectious areas of skin. It can be treated w/ anti-fungal creams.

Athlete’s Foot:
- Ringworm which grows on and digests the warm moist skin between toes. Causes cracking and scaling becoming itchy and sore. It can be treated w/ antifungal creams.