Module 4 Key Words Flashcards
Disease
a departure from good health caused by a malfunction of the mind or body which causes physical, mental or social problems
pathogens
organisms that cause disease
parasites
organisms that live on or in another living thing ( host ) causing it harm.
transmission
the way in which a pathogen or parasite travels from one host to another
vector
an organism which carries a pathogen from one host to another
immune response
the specific response to antigens on the cell surface membrane of a pathogen. it involves lymphocytes and the production of antibodies
primary defences
prevent pathogen from entering the body
secondary defences
attempt to kill a pathogen once it has entered the body
non specific
digests a range of pathogens
antigens
proteins/glycoproteins on the cell surface membrane of cells. foreign antigens stimulate an immune response
antibodies
proteins which identify and neutralise antigens. each is specific to a particular antigen due to the complementary shapes of the antigen and variable region
vaccination
a deliberate exposure to antigenic material which activates the immune system to make an immune response to provide immunity
natural immunity
gained in the normal course of living
artificial immunity
gained by injection which is a deliberate exposure to antibodies or antigens
passive immunity
acquired without the activation of lymphocytes, provided with antibodies not made by the persons own immune system
active immunity
acquired by the activation of the persons own immune system
biodiversity
the range of habitat, the number of different species and the genetic diversity within a species within an area. it takes into account species richness and species evenness.
species richness
the number of different species in the habitat
species evenness
relative numbers of how many individuals of each species
habitat
the place where an organism lives
species
a group of organisms similar in appearance, physiology and genetics whose members are able to interbreed to produce fertile offspring
classification
the process of sorting living things into groups of similar organisms. it reflects how closely related they are and evolutionary relationships
taxonomy
the study of the principles behind classification- the study of the differences between species ( physical and genetic )
phylogeny
the study of the evolutionary relationships between organisms, the study of how closely related they are
variation
differences within a species or between species
adaptation
a feature that enhances survival and long term reproductive success
natural selection
selection by the environment of individuals that show certain favourable variations. these individuals will survive to reproduce and pass on their variations to the next generation
evolution
the gradual change in characteristics of a species over many generations. driven by selective pressures and natural selection
speciation
the formation of a new species from a pre-existing one
selective pressure
an external factor that drives evolution in a particular direction. it might cause competition between individuals or cause some organisms to die whilst others survive
extinct
no members of a species remain. it ceases to exist
critically endangered
likely to become extinct as species numbers have become low due to man made or natural changes in environment
conservation
maintaining biodiversity between species genetic diversity within species and a variety of habitats and ecosystems
conservation in situ
conserving a species in its natural environment
conservation ex situ
conserving an endangered species by activities that take place outside its normal environment
