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Report Thread starter 9 years ago
Hi, I was looking for a list of Biological terms, that are needed for Edexcel Biology AS or/and A2, with their definition next to them. I have been having trouble finding something like this. Can anyone give me a link to where I can find this or something similar.

I'd really appreciate it if anyone could help. :please:
Badges: 0
Report 9 years ago
(Original post by Freyma)
Hi, I was looking for a list of Biological terms, that are needed for Edexcel Biology AS or/and A2, with their definition next to them. I have been having trouble finding something like this. Can anyone give me a link to where I can find this or something similar.

I'd really appreciate it if anyone could help. :please:
Hi Hope this helps! It helped me with my revision!

Autotrophic – organisms which can make their own food
Photosynthesis – the process by which plants make food from carbon dioxide and water using
energy from the sun trapped using chlorophyll contained in the chloroplast.
Heterotrophic – Organisms which eat other organisms to get their food
ATP – Molecules that releases energy when the terminal phosphate bond is broken to form ADP
Redox – Linked oxidation/reduction reactions
Hydrogen acceptor – molecules that accept hydrogen in cellular reactions
Electron transport chain – Series of carriers along which an electron is passed in a series of redox
reactions resulting in the production of ATP
Grana – Stacks of thylakoid within a chloroplast
Thylakoid – membrane disc which is a unit of granum in a chloroplast
Stroma – matrix which surrounds the membrane stacks in a chloroplast
Photosystem I – Chlorophyll complex involved in cyclic and noncyclic photophosphorylation
Photosystem II – Chlorophyll complex involved in noncyclic photophosphorylation
Photochemical reaction- Reaction which depends on light
Photophosphorylation – Process by which ATP is made in plants whereby an excited electron from
PS I is passed along an electron transport chain to produce ATP and returned to PS I
Photolysis – The splitting of a water molecule by light
Calvin cycle – Series of reactions which make up the light independent stage of photosynthesis
resulting in the synthesis of carbohydrates from carbon dioxide
RuBP – 5 carbon compound found in the calvin cycle
RUBISCO – Enzyme involved in the removal of a molecule of CO2 from RuBP
GP – Phosphorylated 3 carbon compound in the Krebs cycle
GALP – Reduced form of GP also part of the Krebs cycle
Ecosystem – Environment including all the living organisms interacting, the cycling of nutrients and
the physical and chemical environment in which the organisms are living
Habitat – Place where an organism lives
Population – Group of organisms of the same species living and breeding together in a particular
niche in a habitat
Community – All of the population of living organisms which live in a habitat at any one time
Ecological niche - The role of an organism within an ecological community
Habitat niche – The role of an organism in relation to a specific habitat
Abiotic factors - nonliving elements of the ecosystem
Biotic factors – The living elements of a habitat the affect an organisms ability to survive there.
Biosphere – all areas of the earth’s surface where living organisms survive
Biomes – Major ecosystems of the world
Succession – Process by which communities of organisms colonising an area change over time
Opportunist/ Pioneer Species – Organisms which are the first to colonise bare rock or sand
Humus – organic component of soil
Climax community – A self sustaining community with relatively constant biodiversity and species
range. The most productive group of organisms that a given environment can support long term
Plagioclimax – a climax community brought about by human intervention
Microclimate – small areas with a distinct climate which is different to the surrounding areas
Leaching - Loss of minerals from soil as water passes through rapidly
Loam – ideal soil with a wide range of particle sizes and plenty of humus
Intraspecific competition – Competition between members of the same species for the same
resources within a community
Interspecific competition – Competition between members of different species for the same
resources within a community
Endemic – found in a particular region or country
Biomass – Mass of biological material in a given organism or habitat
GPP – percentage of the energy from the sun which is transferred into plant material
NPP – percentage of the sun’s energy converted into plant biomass
Food Chain – Simple feeding interactions between organisms in a community
Trophic level - Feeding positions in a food chain or web
Food web – more complex food interaction between organisms in a community
Decomposers – An organism which breaks down dead plant and animal matter
Secondary production – Energy used to make new animal biomass
Carbon sinks - reservoirs where carbon is removed from the atmosphere and locked up in organic
material or inorganic compounds
Greenhouse effect – The way in which greenhouse gases reduce the amount of heat lost from the
surface of the earth
Temperature proxies – Indirect or inferred measurements of the temperature of the earth
Error lines – Indications of the range of error in a given measurement or inference
Mean values – The value obtained by dividing the sum of a set of values by the number of values in
the set
Interglacial – periods between ice ages
Wiggle matching – A process used to calibrate inferred, indirect, or imprecise way of measuring.
Calibration – checking adjusting or standardising a piece of measuring equipment
Correlation – A factor that appears to be linked to a change or event.
Causal relationship – one factor directly causes an effect in another
Extrapolate – Use available data on which to base estimations of value which fall outside the known
Optimum temperature – Temperature at which enzymes work best
Denature – When the tertiary and quaternary structure of the protein is destroyed
Biofuels – Fuels produced from biomass
Genome – All the DNA of an individual
Proteome – All the proteins produced from the DNA of an individual
Allele frequency – The relative frequency of a particular allele in a population
Gene families – A group of closely related genes
Sickle cell disease – A genetic disease affecting the formation of haemoglobin, which in turn affects
the shape of the red blood cells
DNA profiling - using a sample of DNA to identify an individual.
Rigor mortis – the stiffening of the muscles which takes place within a few hours of death as the cells
run out of ATP
Forensic Entomology - The study of insect life in relation to crime
Ribosomes – Cell organelle that is the site of protein synthesis
Triplet Code – Three bases of DNA which code for a single amino acid
Codon – Three base pairs of DNa or RNA coding for a particular amino acid
Transcription – production of mRNA from a DNA strand
Translation – The conversion of the information in mRNA into a polypeptide or protein
mRNA – RNA that carries information from the DNA in the nucleus out into the cytoplasm to be
translated into proteins on the ribosomes
DNA-directed RNA polymerase – enzyme involved in making an RNA copy from a DNA template
using transcription in the nucleus
Template Strand – The DNA strand which provides the template for ordering the sequence of
nucleotides in the mRNA
Sense strand – The DNA strand which has the same sequence as the resulting RNA
Antisense strand – The strand of DNA which acts as a template for the formation of mRNA
tRNA – small unit of RNA that codes for a specific amino acid and attaches to it in the cytoplasm
before carrying it to the surface of a ribosome for protein synthesis
rRNA – RNA which makes up the bulk of the ribosomes
Anticodon – The three base sequences of tRNA which is complementary to the RNA codon of the
mRNA on the surface of a ribosome
Mini satellite – 20-50 base sequence repeated 50-several hundred times in DNA introns
Micro satellite – 2-4 base sequence repeated 5-15 times in a DNA intron
Restriction endonucleases – Enzymes used to chop DNA molecules into fragments at particular point
in the intron sequences
Gel Electrophoresis – Type of chromatography where individual DNA fragments are separated using
an electric current
Southern Blotting – A process in the production of a DNA profile
Gene probe – Short DNA sequences used to identify specific sequences in the production of a DNA
Short tandem repeats – micro-satellite regions of the DNA widely used in DNA identification
Pathogen – A microorganism that causes disease
Toxin – A poison produce by a pathogen and causes disease
Tobacco mosaic virus – First virus to be identified
Envelope – a lipid outer layer found in some viruses
Capsid – protein coat of virus
Capsomeres – Repeating protein units which make up the capsid
Bacteriophages – viruses which infect bacteria
Reverse transcriptase – enzyme used by viruses to produce DNA molecules which correspond to the
viral genome
Plasmid – extra circular strand of DNA, separate from the main chromosome found in bacteria
Lysogenic Pathway – Stage in viral lifecycle when the viral DNA is inserted into the host DNA so it is
replicated everytime the host cell reproduces. The virus is dormant – it does not cause disease
Non virulent – not disease causing
Provirus – Viral DNA inserted into the DNA of the host cell so that it is replicated everytime the host
cell replicates
Lytic pathway – Stage in viral lifecycle when the viral DNA is replicated is replicated independently of
the host cell DNA and the virus is virulent
Virulent – capable of causing disease
Retrovirus – Viruses with RNA as their genetic material and relatively complex lifecycles
Exocytosis – moving substances out of a cell by emptying a membrane bound vesicle
Hypertonic – a solution with a higher solute concentration than the cell contents
Mesosome – infolding of the cell membrane seen in some bacteria
Capsule – Layer of starch, gelatin, protein or glycolipid which protects bacteria from phagocytosis by
white blood cells. This is a slime layer if it is very thin
Pilli – Thread like protein projections from the surface of some bacteria which seem to be used for
attachment to the host cell and for sexual reproduction
Flagella – Thin extension made up of many stranded helix of the protein flagelin which makes about
100 revolutions per second and moves the bacterium along
Peptidoglycan – Parallel polysaccharide chains with short peptide cross-linkages found in bacterial
cell walls
Gram staining – one way of identifying different types of bacteria
Gram positive – Bacteria which stain purply-blue with gram staining
Teichoic acid – chemical found in the walls of gram positive bacteria which binds to the crystal violet
colour in the gram stain to give the typical gram positive colour
Gram negative – Bacteria which stain red with gram staingin
Cocci – spherical bacteria often linked together in chains
Bacilli – Rod shaped bacteria
Spirilla – Bacteria with a twisted shape
Vibrios – comma shaped bacteria
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Report 6 years ago
is this just AS or A2 combined?

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