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OCR AS Biology Module 4

Terms in this set (67)

Classification
The systematic grouping of living things based on characteristics, hierarchical, or phylogenetic relationships
Phylogeny
The evolutionary development of a species
Taxonomy
The classification of organisms in a hierarchical system based on shared characteristics or on phylogenetic relationships inferred from the fossil record or established by genetic analysis.
Variation
Variation refers to an individual that possesses characteristics different from the others of the same kind. Variation can be measured at the individual level, i.e. differences between individual people, or at the population level, i.e. differences between populations living in different regions
Speciation
The process in which new genetically distinct species evolve usually as a result of genetic isolation from the main population
Kingdoms
Prokaryotes, Protoctista, Fungi, Plantae, Animalia
Domains
Archaea, Bacteria, Prokaryota
Evolution
This describes the way in which organisms change over many years as a result of natural selection
Homologous structures
A structure that appears different but has the same underlying structure e.g. pentadactly limb
Analogous structures
Features that are adapted to perform the same function but have a different genetic origin, e.g. tail fins of a whale and a fish.
Divergent evolution
This describe how, from a common ancestor, different species have evolved.
Convergent evolution
Organisms evolve similarities because the organisms adapt to similar environments but their underlying structures are different e.g. insect wing and bird wing
Anatomical adaptations
Physical features such as body covering, camouflage, teeth, mimicry
Behavioral adaptations
Survival behaviors, courtship, migration, hibernation
Physiological adaptations
Poison production, water holding, antibiotic production
Natural Selection
Organisms within a population show variation, those best adapted to a selection pressure, survive, reproduce and pass on their genes.
Species
A group of organisms that can breed to produce fertile offspring
Habitat
The natural home or environment of an animal, plant, or other organism
Biodiversity
The degree of variation of life forms within a given species or ecosystem
Habitat Biodiversity
The number of different habitats found in an area
Species Biodiversity
This has 2 components - Species richness (the number of different species in an area) and Species evenness (a comparison of the numbers of individuals of each species.
Genetic Biodiversity
The variety of genes that make up a species
Random sampling
Selecting individuals by chance. In a random sample, each individual in a population has an equal likelihood of selection.
Opportunistic sampling
The weakest form a sampling as it may not be representative of the population. It uses organisms that are conveniently available.
Stratified sampling
Some populations can be divided into a number of strata (sub-groups) based on a particular characteristic.
Systematic sampling
Systematic allows you to investigate how species change as you move inland from the sea. E.g. belt or line transect
Abitoic factors
Non-living components of an ecosystem. E.g. water availability, temperature, light etc.
Reasons for maintaining biodiversity
Economic, aesthetic and Ecological
In situ conservation
Within the natural habitat
Ex situ conservation
Out of the natural habitat
International Union for the conservation of nature
This organisation assist in securing agreements between nations about conservation of threatened species
CITES
Convention on International trade in Endangered species. Regulates trade of wild animal and plant species.
The Rio convention
This requires countries to develop national strategies for sustainable development.
Countryside stewardship scheme
Government payments to farmers and land managers to enhance and conserve the English landscape.
Parasite
An organism that lives in or on another organism (its host) and benefits by deriving nutrients at the host's expense
Pathogen
An organism (usually a microorganism) which can cause disease
Immune response
The reaction of the cells and fluids of the body to the presence of a substance that is not recognized as a constituent of the body itself
Antigen
A toxin or other foreign substance that induces an immune response in the body, especially the production of antibodies
Antibody
A blood protein produced by B cells in response to and counteracting a specific antigen
Histamine
A chemical released from mast cells that causes inflammation
Lymphocytes
Produced in the bone marrow. There are 2 types, B cells (humoral response) and T cells (cell mediated response)
Phagocytosis
Cell engulfs solid particle to form internal compartment known as a phagosome.
Platelets
Formed in bone marrow, bind to fibrinogen at site of wound to form clot
Thromboplastin
Enzyme from blood platelets, converts prothrombin into thrombin
Prothrombin
protein produced in liver in presence of vitamin K and converted into thrombin
Thrombin
an enzyme which converts fibrinogen to fibrin
Fibrinogen
protein converted to fibrin by thrombin in the presence of ionized calcium
Fibrin
insoluble protein formed from fibrinogen by thrombin
Toxin
Most bacteria produce toxins that damage host cells. B cells produce antitoxins to neutralise these.
Ring rot
A bacterial disease of potatoes, tomatoes and Aubergines
Tobacco Mosaic virus (TMV)
A virus that infects tobacco plants and around 150 other species
Potato Blight
A protist which infects potatoes.
Black sigatoka
A banana disease caused by a fungus
Tuberculosis (TB)
A bacterial disease caused by Mycobacterium tuberculosis
HIV/AIDS
A human viral disease which targets T helper cells
Influenza
A viral infection of the ciliated epithelial cells in the gas exchange system
Malaria
A disease caused by the protist Plasmodium
Ring worm
A fungal disease affecting mammals
Athletes foot
A human fungal disease
Direct Transmission
A pathogen is transferred directly from one individual to another by: direct contact, Inoculation, Ingestion
Indirect Transmission
This is where the pathogen travels from one individual to another indirectly by: Formites. Droplet infection or Vectors.
Active Natural Immunity
Caused by a secondary response to an infection
Passive natural immunity
Immunity caused by the transfer of antibodies from mother via placenta or breast milk
Active Artificial Immunity
A type of immunity caused by vaccinations
Passive artificial immunity
Temporary immunity caused by an injection of of antibodies or antitoxins
Pharmacogenetics
A personalised medicine which is a combination of drugs that work with your individual combination of genetics and disease
Antibiotic resistance
Bacteria have a mutation which means they are either less affected by the antibiotic or they are able to break down the antibiotic.
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