Topic 5- Glossary Flashcards
Biosphere
The part of the earth and its atmosphere which is inhabited by living organisms
Ecosystem
A relatively self-contained, interacting community of organisms
Abiotic
Physical and chemical aspects of an ecosystem
Biotic
Factors determined by organisms- predation and competition
Habitat
The place where the organisms live; the non-living part of an ecosystem;
Microhabitat
Area of distinct conditions within a habitat- e.g underside of a stone in a pond
Population
A group of individuals of the same species living in a particular habitat
Community
The living part of an ecosystem; all the plants and animals that live in a habitat i.e. all the populations
Species
A group of actually or potentially interbreeding natural populations that produce fertile offspring and that is reproductively isolated from other such groups.
Niche
The functional position of an organism in its environment, comprising its habitat and the resources it obtains there, and the periods of time it is active
Biodiversity
The variability among living organisms from all sources; it includes diversity within species, between species and within and between ecosystems
Competition
Intraspecific competition
Interspecific competition
Use of the same resource by two or more species, when the resource is present in insufficient supply for the combined needs of the species.
May be within members of same species ……………………………..
or between members of different species…………………………..
Edaphic factors
Factors connected with the soil structure, texture, pH, mineral content
Mutualism
Relationships in which both partners benefit
Biotic factors show effects related to the size of a population, and so are said to be __________ ________
Density-dependent
Topography
Physical factors of the environment including altitude, slope, aspect, and drainage.
Anthropogenic factors
Factors arising from human activity- biotic or abiotic
Zonation
A change in species composition through a habitat due to a change in environmental factor(s). The ecosystem will be divided into distinct zones, where each zone experiences similar abiotic/biotic conditions. This is particularly clear on a rocky shore. Here the fine balance between tolerance to desiccation and competitive ability is a major cause of the patterns seen.
Sites of Specific Scientific Interest SSIs
*Areas managed and protected to conserve specific rare or endangered species or habitats
Succession
The way in which the different species of organisms that make up a community change over a period of time. Can be seen clearly in sand dune systems.
Pioneer species
An organism that can survive extreme conditions (e.g. low nutrients, low water availability) or the first organism to colonise a newly formed habitat or a habitat that has been cleared of vegetation. Colonisation by these species will start to change the conditions of the habitat making it more suitable for other organisms to colonise.
Climax community
The stable community that make up the final stage of ecological succession. The nature of the climax community will depend on ecological conditions such as the climate.
Primary succession
Succession from an area which has not previously sustained a community, such as bare rock.
Secondary succession
Succession where an previous community has been cleared, e.g. land cleared for building or cleared by fire
Deflected succession
A stable pre-climax community which is maintained only by human activity, e.g. grazing results in this.
Phytoplankton
Algal plankton. Plankton refers to algae and animals kept in suspension by water turbulence. Phyto is a general botanical prefix.
Autotrophs
Organisms that can make their own organic compounds from inorganic compounds
Photosynthesis
The metabolic process by which light energy is trapped and used to fix carbon dioxide into compounds such as glucose.
Chemosynthetic autotrophs
Organisms that can produce organic compounds using energy released from chemical reactions.
OILRIG
Acronym to remember oxidation is loss of, reduction is gain, in electrons.
Photolysis
Splitting water into hydrogen ions, electrons and oxygen molecules, using light energy
Light dependent reaction
The process by which ATP and reduced NADP are generated in photosynthesis using energy from light and hydrogen from photolysis of water. The waste product of this reaction is oxygen.
Light independent reaction
The reactions where the products of the light dependent reaction are used to reduce carbon dioxide to form carbohydrate
Palisade mesophyll
The tall thin cells found near the upper surface of a leaf. They contain many chloroplasts and are an important site of photosynthesis.
Chloroplast
An organelle, bounded by a double membrane, containing a large surface area of membranes with pigments, enzymes and electron carriers required for photosynthesis
Thylakoid membrane
Interconnected, fluid-filled sacs within chloroplasts. Pigments and electron carriers are embedded in the membrane.
Stroma
Fluid surrounding the thylakoid membranes containing enzymes for the light independent reaction.
Granum (plural grana)
A stack of thylakoid membranes, joined together.
Inner chloroplast membrane
The second membrane of a chloroplast containing membrane-bound transport proteins. Regulates the passage of substances in and out of the chloroplast
Outer chloroplast membrane
Surrounds a chloroplast. Freely permeable to oxygen, water and carbon dioxide
Electron transport chain
A series of closely situated electron carrier molecules embedded in the thylakoid membrane
Photophosphorylation
The part of the light-dependent reaction of photosynthesis in which energy released in the electron transfer chain is used to produce ATP. The electrons being transferred were lost from the chlorophyll molecule, when chlorophyll absorbs light energy. Light is the initial energy source for ATP production.
Photosystem I and II
Photosynthetic pigments arranged in clusters in the thylakoid membrane, where several hundred pigment molecules surround a primary chlorophyll molecule. These acts as a sort of light funnel, absorbing light and passing the energy from molecule to molecule until it reaches the primary chlorophyll molecule at the reaction centre.
ATP
The most important energy transfer molecule within cells. Composed of adenine, joined to ribose that is also joined to three phosphate groups. When formed, useful energy is stored; when broken down (third phosphate group lost), energy is released to drive other energy requiring (endergonic) reactions.
Coenzyme
An organic substance which plays an essential part in an enzyme catalysed reaction, but which are only involved temporarily with the enzyme (cf. prosthetic group)
NADP
The coenzyme acting as a hydrogen carrier in photosynthesis.
Calvin cycle
The cyclic part of the light independent reaction of photosynthesis. It consists of a series of reactions in which carbon dioxide is reduced to glyceraldehyde 3-phosphate (GALP), while the carbon dioxide acceptor ribulose bisphosphate is regenerated. For every six molecules of carbon dioxide that enter the cycle, a net gain of two molecules of GALP result.
RuBISCO - ribulose bisphosphate carboxylase
The most common enzyme on the planet. It catalyses the fixation of carbon dioxide in the Calvin cycle
RuBP, Ribulose bisphosphate.
The five carbon compound which combines with carbon dioxide in the Calvin cycle.
Glycerate 3-phosphate (GP)
The first stable 3-carbon molecules produced in the light independent reaction
Glyceraldehyde 3-phosphate (GALP)
3-carbon molecules that combine to form glucose and other carbohydrates in the light independent reaction
Heterotrophs/ consumers
Organisms that take in large organic molecules produced by another species.
Trophic level
Level in a food chain occupied by a particular group of organisms
Omnivore
An organism that feeds on both plants and animals, therefore feeding at more than one trophic level in a food web.
Detritivores
Primary consumers that feed on dead organic matter e.g. wood lice, earthworms. They ingest the material and digest internally.
Decomposers
Species of bacteria and fungi that break down dead organisms and excreted materials. They secrete enzymes and digest externally, before absorbing the small soluble products of digestion.
Absorption spectra
The range of wavelengths of light absorbed by plant pigments
Limiting factors
Factors that cause the rate of a reaction such as photosynthesis to plateau even when other factors are increased.
Gross primary productivity GPP
The rate at which energy from sunlight is incorporated into organic molecules by an ecosystem. It is usually expressed as units of energy per unit area per year. GPP = NPP + respiration.
Net primary productivity NPP
The rate at which energy is transferred into the biomass of plants. Equivalent to the GPP - the energy lost in respiration.
Biomass
The mass of living material in an organism or at a trophic level
Long data sets
Long sequences of data of for example, temperature, rainfall. Old data sets used different equipment and possibly different units of measurement so may also be unreliable
Straight best fit line
A line which goes through or between the points so that the maximum number lie on the line with the others evenly dispersed either side of the line.
Curved line or smoothed line
A line which goes up and down amongst the graph points, picking out overall trends
Peat bogs
Waterlogged areas of poorly decayed organic material, conditions are anaerobic and acidic.
Pollen grains
Microspores of seed plants- particularly well preserved in peat bogs, with a tough outer layer, and distinctive to each plant species that produces it.
14C dating
A method of dating which relies on the decay rate of a carbon isotope
Kite diagrams
A graphical representation of data showing species abundance across a landscape or timescale. The width of the graph shape represents the number of individuals or the % individuals. A single thin line represents species absence (the baseline).
Alder trees
Species of tree which grows in damp soil, often near rivers, lakes and marshes.
Bog beetles
*Insect exoskeletons found in peat bogs. Useful as insects reproduce quickly and any effect of climate change will be readily seen.
Dendrochronology
Dating of past events (climatic changes) through the study of tree rings
Skeleton plots
Graphical representation of tree ring width
Xylem
The woody tissue that conducts water and minerals. Diameter varies according to season of growth- wide in the spring, narrow in the summer, little growth in the autumn and winter.
Tree ring
The contrasting pattern of light and dark areas produced by the seasonal early and late growth of xylem tissue.
Bristle cone pine
*Oldest living trees, approx 4700 years old
Ice cores
Samples taken from glaciers, ratios of different oxygen isotopes or the CO2 concentrations reveal clues about the climate
Industrial revolution
Period in history (from approx 1750) marked by the increase in modernisation and automation of many manufacturing processes, accompanied by an increase in fossil fuel consumption.
Atmosphere
Thin layer of gases, extending 100 km above Earth’s surface, held in place by gravity.
Greenhouse effect
A natural process where infrared radiation is trapped by the atmosphere. It is essential for life on earth, without it the temperature would fluctuate between very hot days and -40C at night.
Global warming
Enhanced greenhouse effect, thought to be caused by an increase in greenhouse gases due to human effects, is leading to this…………………………
Solar radiation
Radiation from the sun
Infra-red
Radiation emitted by the earth after absorbing solar radiation.
Greenhouse gases
Gases in the atmosphere which absorb infra-red radiation therefore warming the troposphere.
Global warming potential
Measure of the greenhouse effect caused by a gas relative to the same amount of carbon dioxide over a given time.
CO2
Greenhouse gas that has the largest effect because of its abundance although it does not have the highest global warming potential (value of 1). Has increased by 42% (as of 2014) since the industrial revolution (1750).
(CFCs) chlorofluorocarbons
Chemicals used in, for example, aerosol propellants and refrigerators.
Dinitrogen oxide or nitrous oxide
Gas released by bacteria during the breakdown of nitrogen compounds in the soil and oceans, and from burning of fossil fuels
Methane
Gas produced by
i) Anaerobic decay of organic material in waterlogged conditions, e.g. bogs and rice fields.
ii) Also produced and emitted from digestive system of cows.
iii) Decay of domestic waste in landfill sites and decomposition of animal waste.
Incomplete combustion of fossil fuels
Fossil fuels
Compounds which are formed over a long period of time from once living organisms, which can be burned to release energy.
Correlation
The relationship between two variables such that a change in one of the variables is reflected by a change in another variable. When two events occur at a similar time they may be linked.
Causal relationship
When a change in one variable is responsible for a change in another variable. It implies a mechanism that can be investigated.
Theory
A well-tested and widely accepted idea or principle supported by a great deal of evidence.
Hypothesis
A proposed explanation for an observation or phenomenon that can be tested.
It should not be confused with the above, as it is used in the initial stages of research, and will have limited evidence to support it.
Controversy
When alternative viewpoints can be validly held.
Kyoto protocol
*International agreement to cut back on greenhouse gas emissions formed in 1997.
Extrapolation
Extending a data set forwards based on existing trends
International Panel on Climate Change (IPCC)
*The group which is cited for much of the work on climate change in his topic.
Community
Group of species found in the same place at the same time
Distribution
If species migrate or change in location we say the ________ of the species has changed.
Dominant
Climate change may cause the balance between species to shift, if conditions favour one species they may become ____________
Heath bedstraw
Distribution of this plant is predicted to be more to the north in the future
Parasite
An organism that relies on another host organism for its survival at the expense of the latter.
Witchweed
A parasitic weed that infects grain crops causing damage and reduced crop yields; requires air temperature of 28C
Some of the non-migratory European Butterflies.
Insects whose distribution has already changed, showing a shift northwards
Alien species
Invading species to an area
Enzymes
Proteins which act as biological catalysts, which work best at optimal temperature and pH conditions
Limiting factor
A factor whose supply/concentration most strongly influences the rate of a reaction for example photosynthesis.
Isoenzyme
*Different forms of the same enzyme
Optical temperature
The temperature at which the rate of reactions is highest
Denatured
If the three dimensional shape of an enzyme is disrupted (due to changes in temp, or pH etc) and the substrate no longer fits into the active site, the enzyme is said to be ________
Q10 or temperature coefficient
A ratio that allows use to us to mathematically describe what happens to the rate of reaction as temperature increases by 10C.
= Rate of reaction at temperature T + 10C
Rate of reaction at temperature T
Above the optimal temperature this relationship no longer applies.
Coral Bleaching
*Death of the alga which lives symbiotically with coral, therefore causing a loss of colour (due to the algae) of the reef.
Environmental cue
An environmental trigger for development or behaviour.
Temperature dependent sex determination
Temperature affects the sex of the young
E.g. leatherback turtles- higher nest temperatures produce females.
Phenology
Study of seasonal events in the lives of animals and plants e.g. timing of flowering, leaf emergence, summer bird arrival etc. Useful biological indicators of climate change.
Photoperiod
The duration of a period of light- i.e. day length.
Mismatch
Organisms have evolved so that life cycles are synchronised with periods of maximum food availability. If that synchronisation was achieved through temperature in one organism and photoperiod in another then a ____________ will occur.
Natural selection
Term given to the mechanism by which better adapted organisms live to produce more viable offspring and so pass on their genes. This has the effect of increasing their proportion in the population so that they become more common.
Allele frequency
This term is defined as the relative frequency of a particular allele in a population
Evolution is a change in ________ _________ in a population of organisms over time.
Peer review
The process by which scientific experts anonymously check a scientists work to see that it is valid, before it is published
Genomics
The study of DNA of a species
Proteomics
The study of the proteins.
DNA hybridisation
A method to measure how similar the DNA from two species is. Based on the temperature it takes for the hybrid DNA to denature.
DNA profiling
A method to see similar the DNA from two species is, which relies on the differences fragments of target DNA. It may use STRs in some organism (see topic 6). It can also use differences in restriction enzyme recognition sites, and whether the DNA can be cut or not due to mutations.
DNA and protein sequencing
The detailed comparison of DNA or proteins by looking at the order of bases in the DNA or amino acids in the proteins.
Molecular clocks
DNA accumulates mutations over time, and the mutations rate can be estimated. Evolutionary relationships and the timings can be measured by measuring the number of mutations. Typically uses mitochondrial DNA which shows maternal inheritance.
Speciation
The creation of a new species from an ancestral population. This requires that the two gene pools became separated in some way. As time progresses and the isolated populations are exposed to different selection pressures, accumulate different mutations, and the two groups become genetically different.
Reproductive isolation
A key step in speciation is that two populations are unable to breed and produce fertile offspring. There is no gene flow between the populations.
Allopatric speciation
This type of speciation occurs where populations are geographically isolated from one another, preventing the groups from mating with each other, and so the population becomes more reproductively isolated.
Sympatric speciation
This type of speciation occurs where two populations become reproductively isolated in the same environment without any geographical barrier, due to other isolating mechanisms. E.g. behaviourally, physically, temporally (reproduce at different times) or as a result of hybrid in viability (hybrids die before they can reproduce) or hybrid sterility.
Carbon cycle
Worldwide circulation of carbon between the atmosphere, and living organisms (but also takes account of fossil fuels).
Positive feedback
When something ‘feeds back’ to increase the action/result: e.g. increase in water vapour as a result of increased temperatures serves to act as a greenhouse gas which further increases temperatures
Compounds such as coal ‘lock in’ carbon and act as _______ ________
Carbon sinks
Deforestation
Cutting down of trees on a large scale
Ecotrons
Artificial chambers containing control plots of land; used to study movement of carbon through an ecosystem
Biofuels
Solid biomass which can be used as fuels, e. wood, straw, ethanol
Methane produced from domestic waste and animal slurry is also called ________
Biogas
Sustainable resources
Resources that are renewable, e.g. plant material that can be regrown.
Carbon dioxide neutral
Where the release of CO2 upon combustion is counterbalanced by the amount of CO2 that was absorbed by photosynthesis. Thus there is no net increase in CO2 into the atmosphere.
Reforestation
Replanting of trees and management of new forests by e.g. coppicing.
