B5 - Communicable Diseases Flashcards
Communicable (infectious) disease
Disease caused by pathogens that can be passed from one organism to another.
Microorganisms
Organisms that are usually single-celled and can only be seen using a microscope . They include bacteria, fungi, viruses and protists.
Non-communicable diseases
Are not infectious and cannot be passed from one organism to another.
Pathogens
Microorganisms that cause disease.
Sexually transmitted disease (STD)
Transmitted from an infected person to an uninfected person by unprotected sexual contact.
Vaccine
Dead or inactive pathogenic material used in vaccination to develop immunity to a disease in a healthy person.
Virus
Pathogens that are much smaller than bacteria and can only reproduce inside living cells of other organisms.
Agar gel
Widely used solid (gel) culture medium used for growing microorganisms.
Aphids
Insects that penetrate the plant phloem and feed on the dissolved food. They act as plant pathogens and are also vectors that carry pathogenic viruses, bacteria, and fungi into healthy plant tissue.
Binary fission
Reproduction by simple cell division, for example in bacteria.
Chlorosis
The yellowing seen on the leaves of plants when they cannot make chlorophyll due to a lack of magnesium ions.
Culture medium
A liquid or gel used to support the growth of microorganisms or other cultures, often containing specific nutrients.
Inoculate
Introducing microorganisms to a culture medium, or introducing modified microorganisms into an individual to protect them against disease.
Mutation
A change in the genetic material of an organism.
How can a plant communicable disease be caused?
By pathogens - bacteria, viruses, fungi and protists.
