mod 4 definitions Flashcards
(130 cards)
1
Q
What is active immunity?
A
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.
2
Q
What are agglutinins?
A
Chemicals that cause pathogens to aggregate together, aiding phagocytosis. Antibodies can act as agglutinins.
3
Q
What is an antibiotic?
A
A chemical or compound produced by a living organism that kills or prevents the growth of bacteria.
4
Q
What are antibiotic-resistant bacteria?
A
Bacteria that mutate to become resistant to an antibiotic, survive and reproduce very rapidly, passing on their antibiotic resistance.
5
Q
What are antibodies?
A
Immunoglobulins produced by B-lymphocytes in response to a specific antigen, triggering an immune response.
6
Q
What is an antigen?
A
A chemical present on the surface of a cell that induces an immune response.
7
Q
What is an antigen-presenting cell?
A
A macrophage that displays foreign antigens.
8
Q
What are anti-toxins?
A
Chemicals produced by white blood cells that neutralise toxins released by pathogens.
9
Q
What is artificial active immunity?
A
The production of antibodies by the immune system following the exposure to a weakened, attenuated or dead pathogen, e.g: by vaccination.
10
Q
What is artificial passive immunity?
A
The immunity acquired from the administration of specific antibodies from another organism, e.g: by vaccination.
11
Q
What is athlete’s foot?
A
A form of ringworm in humans that affects the feet, resulting in cracking and scaling of the skin.
12
Q
What is an autoimmune disease?
A
A condition in which the immune system attacks and destroys healthy body tissue, e.g: arthritis, lupus.
13
Q
What are bacteria?
A
Prokaryotic cells that have cell walls but lack organelles. Some bacteria are pathogenic, producing toxins that damage host cells.
14
Q
What is bacterial meningitis?
A
A severe form of meningitis caused by bacterial infection of the meninges. Complications include septicaemia; a symptom is a rash of purple discolouration that does not fade when a glass is pressed against it.
15
Q
What are B effector cells?
A
A type of B lymphocyte that divides to form plasma cells.
16
Q
What is black sigatoka?
A
A fungal disease in tomatoes caused by Mycosphaerella fijiensis, the hyphae of which penetrate and digest host leaf cells, turning them black.
17
Q
What are B lymphocytes?
A
Lymphocytes that mature in the bone marrow. There are three main types; plasma cells, B effector cells and B memory cells.
18
Q
What are B memory cells?
A
B lymphocytes that provide immunological memory.
19
Q
What is callose?
A
A plant polysaccharide that contains β-1,3 and β-1,6 linkages between glucose molecules. It is deposited between the cell walls and cell membrane in cells adjacent to infected cells, serving as a defence against pathogens.
20
Q
What are chitinases?
A
Enzymes that degrade chitin in fungal cell walls.
21
Q
What is clonal expansion?
A
The mass proliferation of specific antibody-producing cells.
22
Q
What is clonal selection?
A
The identification of an antibody-producing cell with complementary receptors to the shape of a specific antigen.
23
Q
What is Clostridium difficile?
A
A type of bacteria found in the gut of some individuals which is resistant to most antibiotics.
24
Q
What is a communicable disease?
A
A disease that is caused by a pathogen and transmitted directly between organisms.
25
What are cytokines?
Cell-signalling molecules produced by mast cells in damaged tissue. They attract white blood cells to the site of damage.
26
What is 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.
27
What is an epidemic?
A rapid rise in the incidence of a communicable disease at a local or national level.
28
What are expulsive reflexes?
Coughs or sneezes initiated upon irritation of the respiratory tract. They remove microorganism-containing mucus from the gaseous exchange system.
29
What are fungi?
Eukaryotic, often multicellular organisms that may cause disease. They digest and destroy cells, and produce spores that can spread rapidly between organisms.
30
What are glucanases?
Enzymes produced by plants that decompose glucans, polysaccharides found in oomycete cell walls.
31
What is histamine?
A chemical produced by mast cells in damaged tissue. It makes blood vessels dilate and causes their walls to become leakier.
32
What is Human Immunodeficiency Virus (HIV)?
An infectious virus that destroys T helper cells, weakening the immune system of the body. HIV makes an individual more susceptible to opportunistic infections and can lead to AIDS.
33
What is indirect transmission?
The transfer of a pathogen indirectly between organisms via fomites, vectors, droplet infection or soil contamination.
34
What is inflammation?
A localised response of vascular tissue to pathogens, damage or irritants. It is characterised by pain, redness, heat and swelling.
35
What is influenza?
A common viral infection caused by the family of viruses, Orthomyxoviridae, that destroys ciliated epithelial cells in the gaseous exchange system, exposing the airways to secondary infection.
36
What are interleukins?
Cytokines produced by T helper cells that stimulate B cells.
37
What are lymphocytes?
White blood cells that contribute to the specific immune response.
38
What is a lysosome?
A membrane-bound organelle that contains hydrolytic enzymes.
39
What is malaria?
A disease caused by the protoctista Plasmodium that lives within two hosts, mosquitoes and humans. It causes recurrent episodes of fever and can be fatal.
40
What are mast cells?
Specialised cells in connective tissue that are important in the inflammatory response, releasing histamines and cytokines.
41
What is MRSA?
A type of bacteria that is resistant to the antibiotic methicillin.
42
What are mucous membranes?
The membranes lining body cavities that secrete a sticky mucus.
43
What is natural active immunity?
The production of antibodies by the immune system following infection.
44
What is natural passive immunity?
The immunity acquired by an infant mammal when antibodies are transferred through the placenta and the colostrum from the mother.
45
What are non-specific defences?
Defenses that are always present and are the same for all organisms, e.g: skin, blood clotting, inflammation, mucous membranes and expulsive reflexes.
46
What are opsonins?
Chemicals that bind to and tag foreign cells, making them easily recognisable to phagocytes.
47
What is passive immunity?
Resistance in an organism acquired via the transfer of antibodies. It provides short-term immunity as no memory cells are produced.
48
What is a pathogen?
A disease-causing microorganism. Includes bacteria, viruses, fungi and protoctista.
49
What is penicillin?
The first conventional, effective and safe antibiotic derived from the mould Penicillium chrysogenum. It was discovered by Alexander Flemming.
50
What is personalised medicine?
A form of medical care that enables doctors to provide healthcare that is customised to an individual's genotype.
51
What are phagocytes?
Specialised white blood cells that engulf and destroy pathogens. There are two types: neutrophils and macrophages.
52
What is phagocytosis?
The process by which phagocytes engulf and destroy pathogens.
53
What is a phagolysosome?
A vesicle within a phagocyte formed by the fusion of a phagosome and lysosome.
54
What is a phagosome?
The vacuole inside a phagocyte in which a foreign particle is engulfed.
55
What are plasma cells?
B lymphocytes that produce antibodies specific to a particular antigen.
56
What is potato blight?
A disease caused by the fungi-like protoctist Phytophthora infestans whose hyphae penetrate host cells, causing the collapse and decay of the leaves, fruit and tubers.
57
What is the 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.
58
What is protoctista?
A group of eukaryotic, single-celled microorganisms that may cause disease.
59
What is ring rot?
A bacterial disease in tomatoes, potatoes and aubergines that results in damage to the leaves, fruit and tubers. It is caused by the Clavibacter michiganensis bacterium.
60
What is ringworm?
A fungal disease that affects mammals, causing grey-white, circular, crusty lesions on the skin.
61
What is the secondary immune response?
The response of the immune system to a pathogen when it is encountered for a second (third, fourth…etc.) time. Immunological memory gives a rapid production of a large number of antibodies.
62
What is synthetic biology?
The design and construction of new biological entities, as well as the reconstruction of pre-existing natural biological systems.
63
What are T helper cells?
T lymphocytes with CD4 receptors on the cell surface membrane. These bind to antigens on antigen-presenting cells and secrete interleukins.
64
What are T killer cells?
T lymphocytes that produce perforin, destroying pathogens with a specific antigen.
65
What are T lymphocytes?
Lymphocytes that mature in the thymus gland. There are four main types: T helper cells, T killer cells, T memory cells and T regulatory cells.
66
What are T memory cells?
T lymphocytes that provide immunological memory.
67
What is Tobacco mosaic virus (TMV)?
A virus that infects many species of plants, in particular tobacco plants. It damages the leaves, flowers and fruit, and stunts plant growth.
68
What are T regulator cells?
T lymphocytes that regulate the immune response by suppressing other T cells and maintaining tolerance to self-antigens.
69
What is tuberculosis (TB)?
A bacterial disease, caused by Mycobacterium tuberculosis and M. bovis, that damages lung tissue and weakens the immune system.
70
What is vaccination?
The deliberate exposure of an individual to antigens from a pathogen to provide artificial active immunity.
71
What is a vector?
A living or non-living agent that transmits a pathogen between organisms.
72
What are viruses?
Non-living infectious agents that invade host cells and take over cell metabolism, replicating within them.
73
What is adaptation?
A feature of an organism that increases its chance of survival in its environment. An adaptation may be anatomical, physiological or behavioural.
74
What is a belt transect?
A line along a sampled area upon which quadrats are placed at intervals to determine the abundance and distribution of organisms in an ecosystem.
75
What is the binomial system?
The universal system of naming organisms. It is made up of two parts; the first gives the genus and the second, the species e.g. Homo sapiens.
76
What is biodiversity?
The variety of living organisms in an ecosystem.
77
Who is Charles Darwin?
The scientist who developed the theory of evolution by natural selection.
78
What is classification?
The organisation of organisms into groups.
79
What is a community?
All of the populations of different species living together in a habitat.
80
What is conservation?
The maintenance of ecosystems and biodiversity by humans in order to preserve the Earth’s resources.
81
What is continuous variation?
When a characteristic can have any value within a given range e.g. height, mass, heart rate.
82
What is the Convention on Biological Diversity (CBD)?
A treaty that promotes the sustainable use of and maintenance of biodiversity. One of three Rio Conventions.
83
What is the Convention on International Trade in Endangered Species (CITES)?
A treaty that regulates the trade of plants and wild animals across international borders.
84
What is convergent evolution?
The process by which unrelated species evolve similar traits due to exposure to similar environments or selection pressures.
85
What is the Countryside Stewardship Scheme (CSS)?
A scheme in England (1991-2014) that aimed to provide financial incentives to farmers to enhance and conserve the environment.
86
What is discontinuous variation?
When a characteristic can only take certain values e.g. sex, eye colour, blood group.
87
What is a domain?
The highest taxonomic rank. There are three domains; Archaea, Bacteria and Eukaryota.
88
What is evolution?
The gradual change in the allele frequencies within a population over time. Occurs due to natural selection.
89
What is ex situ conservation?
A type of conservation that takes place outside of an organism’s natural habitat e.g. zoos, botanic gardens, seed banks.
90
What is a fossil?
The remains of dead organisms found in rocks which are millions of years old.
91
What is fungi?
A biological kingdom consisting of mushrooms, yeasts and moulds.
92
What is genetic biodiversity?
A measure of the variety of genes that make up a species.
93
What is habitat biodiversity?
A measure of the number of different habitats found within an area.
94
What is in situ conservation?
A type of conservation that takes place within an organism’s natural habitat e.g. wildlife reserves, marine conservation zones.
95
What is interspecific variation?
Differences between members of different species.
96
What is intraspecific variation?
Differences between members of the same species.
97
What is a keystone species?
A species which has an unexpectedly large effect on the environment and is crucial for the maintenance of biodiversity.
98
What is 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.
99
What is a kingdom?
The second highest taxonomic rank. There are five kingdoms: Prokaryotae, Protoctista, Fungi, Plantae and Animalia.
100
What is a 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.
101
What is monoculture?
The growth of one crop in a given area.
102
What is natural selection?
The process by which the frequency of ‘advantageous’ alleles gradually increases in a population’s gene pool over time.
103
What is non-random sampling?
A sampling method in which a sample is not chosen randomly. Three types; opportunistic, stratified and systematic.
104
What is opportunistic sampling?
A type of non-random sampling that involves drawing a sample from part of the population that is conveniently available.
105
What is a phylogenetic tree?
A diagram used to show the evolutionary relationships between organisms.
106
What is phylogeny?
The evolutionary relationships between individuals or groups of organisms.
107
What is a pitfall trap?
A device used to catch small ground surface invertebrates. It consists of a container buried beneath the ground and a roof structure.
108
What are pooters?
A device used in the collection of small insects. It consists of two tubes, one connecting the holding chamber to a mouthpiece (with a filter) and the other to an inlet tube.
109
What are prokaryotae?
A biological kingdom consisting of unicellular prokaryotes (bacteria).
110
What is proportion of polymorphic gene loci?
A measure of genetic biodiversity.
111
What is protoctista?
A biological kingdom consisting of unicellular eukaryotes.
112
What is a quadrat?
A square grid of known area used in sampling to determine the abundance of organisms in a habitat.
113
What is random sampling?
A sampling technique used to avoid bias e.g. creating a square grid and generating random coordinates.
114
What is a seed bank?
A storage of seeds to preserve genetic material.
115
What are selection pressures?
Environmental factors that drive evolution by natural selection and limit population sizes e.g. competition, predation and disease.
116
What is Simpson’s Index of Diversity (D)?
A measurement of diversity that considers both species richness and evenness.
117
What is Spearman’s rank correlation coefficient?
A statistical test used to determine the relationship between two variables.
118
What is species biodiversity?
A measure of species richness and species evenness.
119
What is species evenness?
The number of individuals of each species living together in a community.
120
What is species richness?
The number of different species found within an area.
121
What is stratified sampling?
A type of non-random sampling in which populations are divided into subgroups.
122
What is stratified sampling?
A type of non-random sampling in which populations are divided into strata and a random sample is taken from each, proportional to its size.
123
What is 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.
124
What are sweep nets?
A funnel-shaped net used to catch insects and other small animals.
125
What is systematic sampling?
A type of non-random sampling in which samples are taken from different regions of a habitat.
126
What is a taxon?
Each group within a phylogenetic classification system.
127
What is taxonomic hierarchy?
The arrangement of organisms into successive levels of classification known as taxonomic groups.
128
What is the three-domain system?
A method of classification in which organisms are categorised into three domains and six kingdoms. Developed by Carl Woese.
129
What is a Tullgren funnel?
A device used to extract living organisms from a soil sample.
130
What is variation?
The differences between individuals due to genes, the environment or a combination of both.
