4.1 - Commuicable Diseases Flashcards
Def of a pathogen
A microorganism that causes diseases
Different types of microorganism
Bacteria
Fungi
Virus
Protoctista
What do pathogens infect and why?
They live in the host
Host body creates a good habitat in which microorganisms can live
How do pathogens survive in the host?
They take nutrition form their host
But also cause damage in the process
Features of bacteria
Are prokaryotic cells
Can reproduce rapidly once in the host
Their presence can cause disease by damaging cells or by releasing waste products and/or toxins that are toxic to the host
In plants bacteria often live in vascular tissue and cause blackening and death of tissues
Fungi in animals
They live in the skin of an animal
It’s hyphae forms a mycelium underneaths the skin surface
Can send out specialised reproductive hyphae
These grow to surface of skin to release spores
This can cause redness and irritation
Fungi in plants
Often lives in vascular tissue of plants where it can gain nutrients
Hyphae release extracellular enzymes to digest surrounding tissue - causes decay
Leaves often become mottled in colour, curl up and shrivel, before dying.
Fruit and storage organs, like tubers in potatoes will turn black and decay
Features and effects of viruses
They invade cells and take over the genetic machinery and other organelles of the cell
They cause the cell to manufacture more copies of the virus
Host cell eventually burst, releasing many new viruses which infect healthy cells
Features and effects of protoctista
Enter host cell and feed on contents as they grow.
Malarial parasite “Plasmodium” has immature forms that feed on haemoglobin inside RBCs
Info about TB
Tuberculosis
Bacteria
Affects and kills may cells and tissues in the body, most often lungs
Info about bacterial meningitis
Bacteria
Infection of the meninges - membranes surrounding nerves and spinal cord
Causes damage to these areas
Info for ring rot
Bacteria
Affects plants
Causes ring of decay in vascular tissue of potato tuber or tomato, accompanied by leaf wilting
Info about HIV/AIDS
Virus
Attacks cells in the immune system and compromises the immune response
Info about influenza
Virus
Attacks respiratory systems and causes muscle pains and headaches
Tobacco mosaic virus info
Virus
Affects plants
Causes mottling and discolouration of leaves
Blight info(tomatoes and potatoes)
Protoctista
Affects plants
Affects both leaves and potato tubers
Ringworm(cattle)
Fungus
Growth of fungus in skin with spore cases erupting through skin to cause a rash
Athlete’s foot(humans)
Fungus
Growth under skin of feet - particularly between toes
Malaria info
Protoctistan
Parasite in blood that causes headaches and fever and may progress to coma and death
Def of direct transmission
Passing a pathogen form host to new host, with no intermediary
Def of indirect transmission
Passing a pathogen from host to new host, via a vector
Def of transmission
Passing a pathogen from an infected individual to an uninfected individual
Def of vector
An organism that carries a pathogen from one host to another
Short life cycle of a pathogen
Transmission from one host to another
Entering the host’s tissues
Reproducing
Leaving the host’s tissues