B5 Communicable diseases

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

communicable (infectious) disease

disease caused by pathogens that can be passed from one organism to another

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

Microorganisms

organisms that are usually single-celled and can only be seen using a microscope . They include bacteria, fungi, viruses and protists

Mutation

a change in the genetic material of an organism

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