Transmission, Protists, Fungi Flashcards
(42 cards)
How are infectious diseases classified?
By the pathogen that caused them
What are the examples of direct transmission?
-Person to person
-Airborne e.g. aerosols, droplets
-Exchange of bodily fluids
-Direct contact with animals or animal waste
What are the examples of indirect transmission?
-Vehicles e.g. food, water
-Vector e.g. malaria
-Surfaces, objects
What is physical contact?
Direct contact with an infected person e.g. chicken pox, common cold, measles
What is mother to child transmission?
An infection directly from the mother to an embryo, fetus or baby during pregnancy, childbirth or breastfeeding
e.g. HIV, syphilis, hepatitis B
What is zoonoses?
Physical contact with animals, diseases that animals can give to humans
e.g. rabies, lyme disease
What is a vector?
A living thing that carries a disease, it is a causing disease to a host
e.g. fleas, malaria
What is airborne?
Diseases spread through particles suspended in the air
e.g. measles, TB
What is vehicle/formite borne?
Disease spread from contaminated surfaces
e.g. tetanus, influenza, sepsis
What is food and welcome?
Disease spread through contaminated food and water sources or nutritional related
e.g. cholera, mad cow disease
What is bacteriophages?
Viruses that target bacterial cells
What is viral specificity?
Viruses often specific to a certain cell type due to the presence/absence of antigen markers
What is virus entry?
Inject only their DNA inside a host cell or those that inject animal cells can be wholly engulfed or have their lipid envelope fuse with the cell membrane
What is influenza’s mode of transmission?
-Targets ciliated epithelial cells of the respiratory tract
-Viruses inserts its RNA into cell, uses host cell machinery to produce new viral proteins an eventually new virus proteins
How is influenza spread?
-Droplets e.g. coughs, sneezes
-Direct contact with an infected person
-Contact with a contaminated surface or infected animal waste
-Animal to person (zoonotic)
What is the World Health Organisation (WHO)?
Monitors and reports on emerging and infectious diseases
What are the parts of bacteriophage?
-Capsome = repeating protein unit which makes up the protein coat
-Capsid = protein coat
-Nucleic acid = genetic material, double or single stranded
-Receptors/tail = viral proteins often involved in attachment to host cells
-Envelope = lipid derived from host cell membranes, not always present
What are the features of fungus?
-Single celled
-Cell walls made of chitnin and glycans
-Don’t photosynthesise
-Parasites or saprophytes (obtain food by absorbing dissolved organic matter)
What is the mode of infection for fungus?
-Spores are used for reproduction
-Many fungi grow as hyphae which are long thread like fillements emerging from the spore which penetrate the stomata or stem
How does hyphae work?
-Hyphae secret enzymes which digest the plant cells
-Nutrients are absorbed into the fungus
-Hyphae branch to form a mycellium that feeds and grows
-Often hidden in the stem/leaves of the plant
How does fungi affect crops?
-Mycelium grows into vascular tissue absorbing water and nutrients
-Absorbs nutrients from plant which reduces the yield
-Pustules break the plants epidermis making transpiration difficult
-Weakens the stem meaning plants are more likely to fall over
What are the malaria statistics?
-One of the worlds largest killers
-Infects up to 250 million and kills nearly 800,000 every year
-Child dies every 45 seconds due to malaria
-Children are most at risk as they don’t have natural immunity
How is malaria caused?
-5 species of single celled protozoan parasite
-Only females can pass on malaria as they need the additional protein from blood to develop their eggs
What is the life cycle of malaria?
-Extracellular and intracellular forms
-Sexual reproduction in mosquitoes
-Asexual reproduction in the liver cells and red blood cells of humans
