biodiversity, evolution and disease Flashcards
active immunity
resistance in an organism that has developed through the production of specific antibodies in response to a pathogen
it provides long-lasting immunity as memory cells are produced
agglutinins
chemicals that cause pathogens to aggregate together, aiding phagocytosis
antibodies can act as agglutinins
antibiotic
a chemical or compound produced by a living organism that kills or prevents the growth of bacteria
antibiotic-resistant bacteria
bacteria that mutate to become resistant to an antibiotic, survive and reproduce very rapidly, passing on their antibiotic resistance
antibodies
immunoglobulins produced by B-lymphocytes in response to a specific antigen, triggering an immune response
antigen
a chemical present on the surface of a cell that induces an immune response
antigen-presenting cell
a macrophage that displays forgein antigens
anti-toxins
chemicals produced by white blood cells that neutralise toxins released by pathogens
artificial active immunity
the production of antibodies by the immune system following the expose to a weakened, attenuated or dead pathogen
artificial immunity example
vaccination
artificial passive immunity
the immunity acquired from the administration of specific antibodies from another organism
athlete’s foot
a form of ringworm in humans that effects the feet, resulting in cracking and scaling of the skin
autoimmune disease
a condition in which the immune system attacks and destroys healthy body tissue
bacteria
prokaryotic cells that have cell walls but lack organelles
some are pathogenic (produce toxins that damage host cells)
bacterial meningitis
a severe form of meningitis caused by bacterial infection of the meninges
complications of bacterial meningitis include septicaemia (a symptom of this is a rash of purple discolouration that does not fade when a glass is pressed against it)
b effector cells
a type of b lymphocyte that divides to form plasma cells
black sigatoka
a fungal disease in tomatoes cause by mycosphaerella fijiensis
the hyphae of which penetrate and digest host leaf cells - turning them black
b lymphocytes
lymphocytes that mature in the bone marrow
three main types: plasma cells, b effector cells and b memory cells
b memory cells
b lymphocytes that provide immunological memory
callose
a plant polysaccharide
contains b-1,3 and b-1,6 linkages between glucose molecules
deposited between the cell walls and cell membrane in cells adjacent to infected cells, serving as a defence agaisnt pathogens
also found in the cells walla of infected cells and the plasmodesmata between infected cells
chitinases
enzymes that degrade chitin in fungal cells walls
clonal expansion
the mass proliferation of specific antibody-producing cells
clonal selection
the identification of an antibody-producing cell with complementary receptors to the shape of a specific antigen
clostridium difficile
a type of bacteria found in the gut of some people
its resistant to most antibiotics
communicable disease
a disease that is caused by a pathogen and transmitted directly between organisms
cytokines
cell signalling molecules produced by mast cells in damaged tissue
they attract white blood cells to the site of damage
direct transmission
the transfer of a pathogen directly from one organism to another
this can occur via direct contact, ingestion or the sharing of contaminated needles
epidemic
a rapid rise in the incidence of a communicable disease at a local or national level
expulsive reflexes
coughs or sneezes intiated upon irritation of the respiratory tract
they remove microorganism-containing mucus from the gaseous exchange system
fungi
eukaryotic, often multicellular organisms that may cause disease
they digest and destroy cells, and produce spores that can spread rapidly between organisms
glucanases
enzymes produced by plants that decompose glucans, polysaccharides found in oomycete cell walls
histamine
a chemical produced by mass cells in damaged tissue
makes blood vessels dilate and causes their walls to become leakier
human immunodeficiency virus (HIV)
infectious virus that destroys T helper cells, weaking the immune system of the body
makes sufferers more susceptible to infections and can lead to AIDS
indirect transmission
the transfer of a pathogen indirectly between organisms via fomites, vectors, droplet infection or soil contamination
inflammation
a localised response of vascular tissue to pathogens, damage or irritants
its characterised by pain, redness, heat and swelling
influenza
a common viral infection caused by the family of viruses orthomyxoviridae
destroys ciliated epithelial cells in the gaseous exchange system, exposing the airways to secondary infection
interleukins
cytokines produced by T helper cells that stimulate B cells
lymphocytes
white blood cells that contribute to the specific immune response
lysosome
a membrane bound organelle that contains hydrolytic enzymes
malaria
a disease caused by the protocista plasmodium that lives within two hosts (mosquitoes and humans)
causes recurrent episodes of fever and can be fatal
mast cells
specialised cells in connective tissue that are important in the inflammatory response, releasing histamines and cytokines
MRSA
a type of bacteria that is resistant to the antibiotic methicillin
mucous membranes
the membranes lining body cavities that secrete a sticky mucus
natural active immunity
the production of antibodies by the immune system following infection
natural passive immunity
the immunity acquired by an infant mammal when antibodies are transferred through the placenta and the colostrum from the mother
non-specific defences
defenses that are always present and are the same for all organisms
opsonins
chemicals that bind to and tag forgein cells, making them easily recognisable to phagocytes
passive immunity
resistance in an organism acquired via the transfer of antibodies
it provides short term immunity as no memory cells are produced
pathogen
a disease-causing microorganism
includes bacteria, viruses, fungi and protocista
penicillin
discovered by alexander flemming
the first conventional, effective and safe antibiotic derived from the mould penicillium chrysogenum
personal medicine
form of medical care that enables doctors to provide healthcare that is customised to an individual’s genotype
phagocytes
specialised white blood cells that engulf and destroy pathogens
two types: neutrophils and macrophages
phagocytosis
the process by which phagocytes engulf and destroy pathogens
phagolysosome
a vesicle within a phagocyte formed by the fusion of a phagosome and lysosome
phagosome
the vacuole inside a phagoctye in which a forgien particle is engulfed
plasma cells
b lymphoctyes that produce antibodies specific to a particular antigen
potato blight
a disease caused by the fungi-like protocist phytophtora infestans whose hypae penetrate host cells, causing the collapse and decay of the leaves, fruit and tubers
(also known as tomato blight or late blight)
primary immune response
the response of the immune system to a pathogen when it is first encountered
a small number of antibodies are produced slowly
protocista
a group of eukaryotic, single celled microoragnisms that may cause disease
they digest cells and use the cell contents to reproduce
ring rot
a bacterial disease in tomatoes, potatoes and aubergines that results in damage to the leaves, fruit and tubers
caused by the bacterium clavibacter michiganensis
ringworm
a fungal disease that affects mammals, causing grey/white, circular, crusty lesions on the skin
secondary immune response
the response of the immune system to a pathogen when it is encountered for a second (or more) time
immunological memory gives a rapid production of a large number of antibodies
synthetic biology
the design and construction of new biological entities, as well as the reconstruction of pre-exsisting natural biological systems
t helper cells
t lymphocytes with CD4 receptors on the cell surface membrane
these bind to antigens on antigen-presenting cells and secrete interleukins
t killer cells
t lymphocytes that produce perforin, destroying pathogens with specific antigen
t lymphocytes
lymphocytes that mature in the thymus gland
four main types: t helper cells, t killer cells, t memory cells and t regulatory cells
t memory cells
t lymphoctyes that provide immunological memory
tobacco mosaic virus (TMV)
a virus that infects many species of plant - in particular tobacco plants
it damages the leaves, flowers and fruit and stunts plant growth
t regulator cells
t lymphocytes that regulate the immune response by suppressing other t cells and maintaining tolerance to self-antigens
tuberculosis (TB)
a bacterial disease, caused by mycobacterium tuberculosis and M. bovis, that damages lung tissue and weakens the immune system
vaccination
the deliberate exposure of an individual to antigens from a pathogen to provide artificail active ummunity
vector
a living or non-living agent that transmits a pathogen between organisms
viruses
non-living infectious agents that invade host cells and take over cell metabolism, replicating within them
adaptation
a feature of an organism that increases its chance of survival in its environment
an adaptation may be anatomical, physiological or behavioural
belt transect
a line along a sampled area upon which quadrants are placed at intervals to determine the abundance and distribution of organisms in an ecosystem
binomial system
the universal system of naming organisms
made up of two parts; the first as the genus and the second the species
biodiversity
the variety of living organisms in an ecosystem
charles darwin
the scientist who developed the theory of evolution by natural selection
classification
the organisation of organisms into groups
community
all of the populations of different species living together in a habitat
conservation
the maintenance of ecosystems and biodiversity by humans in order to preserve the earth’s resources
continuous variation
when a characteristic can have any value within a given range
convention on biological diversity (CBD)
a treaty that promotes the sustainable use of and maintenance of biodiversity
one of thee rio conventions
convention on international trade in endangered species (CITES)
a treaty that regulates the trade of plants and wild animals across international borders
convergent evolution
the process by which unrelated species evolve similar traits due to exposure to similar environments or selection pressures
countryside stewardship scheme (CSS)
a scheme in England that aimed to provide financial incentives to farmers to enhance and conserve the environment
discontinuous variation
when a characteristic can only take certain values (eg sex, eye colour, blood group)
domain
the highest taxonomic rank
three domains: archeae, bacteria and eukaryota
evolution
the gradual change in the allele frequencies within a population over time
occurs due to natural selection
ex situ conservation
a type of conservation that takes place outside of an organism’s natural habitat
fossil
the remains of dead organisms found which are millions of years old
fungi
a biological kingdom consisting of mushrooms, yeasts and moulds
genetic biodiversity
a measure of the variety of genes that make up species
habitat biodiversity
a measure of the number of different habitats found within an area
in situ conservation
a type of conservation that takes place within an organisms natural habitat
interspecific variation
differences between members of different species
intraspecific variation
differences between members of the same species
keystone species
a species which has an unexpectedly large effect on the environment and is crucial for the maintenance of biodiversity
kick sampling
a method used to sample organisms living on the bed of a river
it involves disturbing an area of river bed before placing a net downstream to capture released organisms
kingdom
the second highest taxonomic rank
five kingdoms: prokaryotae, protocista, fungi, plantae and animalia
line transect
a line along a sampled area
the species touching the transect at regular intervals are recorded to determine the abundance and distribution of organisms in an ecosystem
monoculture
the growth of one crop in a given area
natural selection
the process by which the frequency of ‘advantageous’ alleles gradually increases in a population’s gene pool over time
non-random sampling
a sampling method in which a sample is not chosen randomly
three types: opportunistic, stratified and systematic
opportunistic sampling
a type of non-sampling that involves drawing a sample from part of the population that is conveniently available
phylogenetic tree
a diagram used to show the evolutionary relationships between organisms
pitfall trap
a device used to catch small ground surface invertebrates
it consists of a container buried beneath the ground and a roof structure
pooters
a device use to catch small ground surface invertebrates
consists of two tubes one connecting the holding chamber to a mouthpiece (with a filter) and the other to an inlet tube
prokaryotae
a biological kingdom consisting of unicellular prokaryotes (bacteria)
proportion of polymorphic gene loci
a measure of genetic biodiversity
proportion of polymorphic gene loci calculation
number of polymorphic gene loci / total number of loci
protoctista
a biological kingdom consisting of unicellular eukaryotes
quadrat
a square grid of known area used in sampling to determine the abundance of organisms in a habitat
two types: point quadrats and frame quadrats
random sampling
a sampling technique used to avoid bias
seed bank
a storage of seeds to preserve genetic material
selection pressures
environmental factors that drive evolution by natural selection and limit population sizes
simpson’s index of diversity (D)
a measurement of diversity that considers both species richness and eveness
simpson’s index of diversity calculation
D = 1 - £(n/N)2
spearman’s rank correlation coefficient
a statistical test used to determine the relationship between two variables
species biodiversity
a measure of species richness and species evenness
species evenness
the number of individuals of each species living together in a community
species richness
the number of different species found within an area
stratified sampling
a type non-random sampling in which populations are divided into strata and a random sample is taken from each, proportional to its size
student’s t-test
a statistical test used to analyse whether there is a significant difference between the means of data values of two populations
sweep nets
a funnel shaped net used to catch insects and other small animals
systematic sampling
a type of non-random sampling in which samples are taken from different regions of a habitat
taxon
each group within a phylogenetic classification system
taxonomic hierarchy
the arrangement of organisms into successive levels of classification known as taxonomic groups
three-domain system
a method of classification in which organisms are categorised into three domains and six kingdoms
developed by Carl Woese
tullgren funnel
a device used to extract living organisms from a soil sample
variation
the differences between individuals due to genes, the environment or a combination of both
