Producer
Autotrophs. Organisms at the start of the food chain that convert inorganic matter into organic matter via photosynthesis.
Systematic sampling
Taking samples from fixed intervals across a habitat. E.g., using line transects and belt transects.
Random sampling
Sampling method where each individial unit has an equal chance of being selected. An area might be split up into grids and a random number generator used. At least 10 quadrat samples should be taken.
Habitat
The place where a community of organisms is found.
Abiotic factors
Non-living factors affecting an ecosystem. Physical and chemical factors (soil type, climate, temperature, pH)
Biotic factors
Factors affecting ecosystems determined by organisms (food availability, predation, competition, disease).
Interspecific competition
Organisms of different species compete with each other for the same resources (leads to available resources being reduced for BOTH populations)
Intraspecific competition
Competition between individuals of the same species. This drives evolution (survival of the fittest / best adapted)
Predation
Where one organism kills and eats another organism.
Structural niche
Location of an organism in its environment
Feeding niche
Types of food eaten by an organism.
Trophic levels
Successive levels of feeding niches. Shows energy flow in ecosystems. Only 10% of energy/biomass is transferred.
Autotrophic nutrition
The synthesis of organic molecules (glucose, amino acids, nucelotides) from simple inorganic molecules (carbon dioxide, water, minerals)
Gross Primary Productivity
The total amount of energy fixed as chemical energy during photosynthesis carried out by producers.
Net Primary Productivity
GPP - respiration. Products which are incorporated into the producer's biomass (proteins, starch, cellulose etc.)
Biomass
The dry mass of all of the living organisms in an area
Productivity
The energy built into the organisms of a trophic level in the food chain. Measured in kilojoules per square metre per year.
Detritivore
Organisms that feed off waste organic matter
Decomposer
Organisms that break down organic waste matter into inorganic matter
Herbivores
Organisms that only eat producers
Consumers
Heterotrophs. Organisms that feed off other organisms.
Omnivores
Organisms that consume both producers and consumers
Biomass transfer efficiency
The proportion of energy transferred between biomass levels - calculated as (biomass at higher level / biomass at lower level) * 100 (%)
Anthropogenic climate change
Changes in the climate that are caused by human activity
Dendrochronology
The use of tree rings to work out data about the tree and its environment which can be useful for analysing changes in climate conditions.
Sustainable
Resources which can be continually renewed and used without being depleted.
Greenhouse effect
The increase of global temperatures caused by the trapping of solar heat by gases in the atmosphere
Allopatric speciation
The development of new species over time following the geographic isolation of populations of a species
Sympatric speciation
The development of a new species over time in the same area as the original species without any geographical isolation. Could be pre-zygotic or post-zygotic isolation.
Gene flow
The movement of genes / alleles between interbreeding populations of a particular species.
Carbon cycle
The processes which cycle carbon through the environment, living organisms and the atmosphere.
Biofuels
Fuels produced using biomass. Carbon neutral, renewable, can be made from waste products. Encourages deforestation, conflicts of space with food sources. Process to make fuels isn't always carbon neutral.
Natural selection
The process by which the frequency of beneficial alleles gradually increases in a population's gene pool over time.
Succession
A directional change / sequence of changes in a community over time.
Climax community
A community that reamins stable and shows little change over time (final stage of succession).
Pioneer species
The first species to occupy a new area
Colonisation
The occupation of a new area by a species
Directional selection
A type of selection that favours one extreme phenotype and selects against all other phenotypes.
Phosphorylation
Addition of a phosphate group (also a condensation reaction).
Photophosphorylation
Addition of a phosphate group (to ADP) using light
Hydrolysis
Splitting a molecule using water
Photolysis
Splitting a molecule using light energy
Thylakoid membrane
Phospholipid bilayer with chlorophyll molecules embedded. Site of the light-dependent reaction and ATP synthesis.
Double membrane
Envelope of the chloroplast permeable to oxygen, carbon dioxide, glucose and some ions with an inter-membrane space.
Granum
A stack of thylakoids. Creates a large surface area to increase light-trapping effieciency.
Stroma
Aqueous fluid matrix, site of the light-independent reactions in the chloroplast. Contains enzymes, sugar, organic acids and oil droplets.
Lamella
Sticks thylakoid stacks together to form grana.
Starch grain
Excess polysaccharides made during photosynthesis are stored temporarily as starch.
ATP
Energy released from glucose is used to make this from ADP & Pi. Consists of adenine (nucleotide base), ribose sugar (5 carbon), and 3 phosphate groups.