Communicable diseases Flashcards
what is a pathogen?
a microorganism that causes disease
why is a host body good for a pathogen
a host body creates a good environment for the pathogen to live in as it can live of the nutrients caused by the cells
what does the pathogen do to the host body
causes damage to the cells and takes nurients from the host
what kingdom does bacteria belong to
prokaryotae
How does bacteria harm the body
they damage cells and release toxins and waste substances that are harmful to the host
- in plants they live in the vascular tissue
where does fungi live
fungi lives in the skin of an animal where its hyphae, this forms a mycelium which grows under the skins surface
- in plants it lives in the vascular tissue where it gains nutrients
how does fungus cause irritation and redness
it sends out special reproductive hyphae which grows on the surface of the skin to release spores this causes the redness and irritation
in plants what does the hyphae do
it releases extracellular enzymes such as cellulases which digest the surrounding tissue and cause decay
what are the symptoms of fungi in plants
- leaves - mottled in colour, curl up, shrivel and die
- fruit - turn black and decay
what doe viruses do inside the cell
they invade the cell and take over the genetic machinery and other organelles of the cell
cell then manufactures more copies of the virus
host cell then bursts and new viruses invade other cells
what do protoctista do?
they enter host cells and feed on the content as they grow
what are the 4 types of pathogen
fungi, bacteria, protoctista, viruses
tuberculosis
- bacteria
- affects many parts but kills cells and tissues, lungs are most affected
bacterial meningitis
- bacteria
- infection of the meninges, membranes that surround the brain and spinal cord, the membrane swell and cause damage to the brain and nerves
ring rot
- bacteria
- ring of decay in vascular tissue of a potato tuber or tomato accompanied by leaf wilting
HIV/AIDs
- virus
- attacks cells in the immune system and compromises immune response
influenza
- virus
- attacks respiratory system and causes muscle pains and headaches
tobacco mosaic virus
- virus
- causes mottling and discolouration of leaves
black sigatoka (banana)
- fungi
- causes leaf spots in banana a plants reducing yield
blight (tomato and potatoes)
- protoctistan
- affect both the leaves and potato tubers