Due to dark prevailing as an external factor preventing normal vision, the eyes become more sensitive to light and therefore visualise the external environment more clearly, an adaptation to combat the blindness caused by the dark.

Processes in photosynthesis that do not require light such as the thermochemical stage (the Calvin Cycle).

An example of adaptive radiation, supporting Charles Darwin's work on natural selection

Darwin, Charles

An English biologist who is renowned for his work and theories in his book On the Origin of Species by means of Natural Selection. His work is elaborated upon in the genetics and evolution tutorial.

The theory that was created by the English biologist Charles Darwin, where the 'survival of the fittest' in species would guarantee long term survival. See the natural selection tutorial.

Factual information in which decision making can be based upon. Data can be collected and be translated to have an informational value. The population of ducks in a given area may simply be data, but the data has an informational value when considering wh.

The folding up of leaves in dry hot conditions to reduce water loss via the stomata. The folding together will also bring the edges of the leave closer, therefore when water is transpired, there is a relatively hi.

The parts of the respiratory system where gaseous exchange does not occur, such as the trachea and bronchioles. These areas make gaseous exchange possible but do not host a means of doing so.

An occurrence where the wings of an organism are lost or shed, usually due to a cyclic occurrence in their life time such as the reproductive stage.

Usually measured by deaths per 1000 of population, the death rate is the number of a species which die, usually measured along side the birth rate to determine long term population trends.

The removal of the carbon element of a molecule.

The decomposition of biological tissue into more simpler forms, usually catalysed by the presence of fungi and bacteria so they can extract energy from the decaying material.

Trees that lie dormant during the colder and darker winter months, and shed leaves during the autumn (because photosynthesis is not a priority in the winter months).

Decomposers are organisms that breakdown organic material, and form an important part of food chains. The material that they break down can then be used by the primary producers of an ecosystem which once again passes through the food chain.

The breaking down of a material into a less complicated chemical structure.

A shortage of a required element or compound, such as a deficiency in Vitamin C in humans leading to the deficiency disease scurvy.

The clearance of a forest, commonly occurring in third world countries for crop-rotation purposes.

A substance that lacks or has a lower than average concentration of water.

An enzyme that is used to remove hydrogen from its substrate, which is used in the cytochrome (hydrogen carrier) system in respiration to produce a net gain of ATP

Dehydrogenation

Pertaining to an oxidised molecule which has had hydrogen removed from it.

A genetic mutation where part of the genetic code is removed from a chromosome and lost forever. This affects the overall genetic sequence, and the result can range from insignificant to fatal.

The study of annual tree rings determining its age and factors that affect them.

Factors which affect the population of a species which are dependant on the actual population size of the species. These can range from increased predation (higher frequency falling to prey), shortage of food and poisoning from waste (from more organisms of the same species. Compare with density independent factor.

Factors which affect the population regardless of its population size. These are usually abiotic factors such as forest fires and a high soil pH. Compare with density dependant factor.

See D.N.A.

Dermatitis

A skin condition resulting in inflammation.

The layer of skin below the epidermis, where the epidermis is in direct contact with the external environment and the dermis lies beneath.

An organism that feeds on detritus, decomposed material which is absorbed by these animals as a means of food.

The growing stage of organisms from embryo to adult.

The are two types of diabetes. Diabetes mellitus involves irregular blood sugar concentration, where a lack of insulin results in excess sugar in the bloodstream and urine, due to the fact that it is not being stored as glycogen where it can be used on-demand. The other type of diabetes, diabetes insipidus, results in excess urine being excreted by the sufferer.

Identification of a condition due to the symptoms which are expressed. A diagnosis also applies to taxonomic classification, where the characteristics of an organism are diagnosed to determine which taxonomic classification is suitable to them.

The last stage of prophase in meiosis.

The process of separating larger molecules from smaller molecules that occurs in kidney dialysis for example, where a machine takes a role of a kidney and filtrates blood.

Tissue found in mammals that can be found around the lungs, which plays a role in breathing.

The occurrence in meiosis where the divided chromosome sets congregate at adjacent poles.

Pertaining to a chromosome that possesses two centromeres.

See Cell Differentiation

Diffusion

The movement of molecules along a concentration gradient, i.e. from areas of high concentration to a low concentration until their is an equilibrium. The more complex and larger the molecules undergoing diffusion, the longer the process takes until there is an equal concentration in both environments.

Occurring in the digestive system where whole foodstuffs are broken down into smaller components until they are sufficiently small enough to enter the bloodstream.

Where digestive activities occur, that breakdown food at the molecular level.

The metatarsals of mammals (the hands and toes).

Describing a finger like appearance.

Pertaining to an organism with two different alleles for a gene responsible for a phenotype.

Drugs responsible for the enlargement of a structure, such as the arteries.

A tissue responsible for the opening and closing of orifices such as the retina for focusing.

A substance with 'watered down' chemical properties by adding a chemical that can neutralise its effect.

Toxic substances that are byproducts of certain chemicals like herbicides that are used to kill off weeds in arable farmland.

Pertaining to homologous chromosomes, where each chromosome number has a pair of chromosomes, such as the 23 pairs in humans totalling our 46 chromosome compliment.

The process of natural selection involving the genome for a species directionally choosing certain genes to remain prominent in the species, such as a growth in size in response to predation.

Complex sugars created by the fusion of two monosaccharides (simpler sugars).

Pertaining to a geographical barrier disrupting gene flow.

A condition in organisms as a result of viral, fungal or bacterial attack that threatens or inhibits the life of the organism in question.

Chemicals that are used to sterilise an area.

The seperation of homologous chromosomes during nuclear divisions.

A platform for communication between species, a given animal may use a threat display to point out that they own this part of the territory.

A receptor responsible for recognising the distance between an organism and its external environment and the objects around them.

A behavioural adaptation by animals to divert a predators attention from their young and in other similar circumstances. Through co-operative hunting, some animals may distract their prey while the others move .

A deceiving type of behaviour used by animals to distract predators or other potential danger. For instance, an animal protecting its young will distract a predator by diverting its attention elsewhere. The animal may appear injured, this easier prey and .

Increased excretion of urine as a result of lower ADH levels, characterised by a higher concentration of water in the urine.

Substances that promote diuresis, such as caffeine found in coffee.

The tracing back of adaptive radiation in species back to their common ancestor can indicate how these organisms have diversified and diverged.

The creation of daughter cells from one parent cell.

A major category of plant classification used in taxonomy.

An acronym for one of the nucleic acids, standing for deoxyribonucleic acid. DNA contains all the genetic information required to create an organism of a species. One cell also contains all this genetic information which is capable of being cloned to produce an exact copy of its parent. The DNA material in an organism provides the information that is passed on to offspring.

The fingerprints are a bar-code like occurrence which can distinguish the uniqueness of one individual from another. This can be used to determine the presence of someone at a particular time by matching their fingerprints at the scene.

An enzyme that promotes the joining up of adjacent bonds in a polynucleotide chain, which is used in gene.

The process where damaged DNA is recognised and either repaired in part or in full.

The deciphering of the exact order of base sequence in a nucleotide sequence.

A genetic term used to describe how the characteristics expressed by one allele (the dominant one) masks the characteristics expressed by another, known as the recessive allele.

A species within a given environment that exerts much influence on other species, and is most likely at the top of the food chain. See dominance

Donor

Someone who donates part of their tissue to another, who may have some kind of disease or disorder that is life threatening and requires the donation.

A state when organisms are in unfavourable conditions, and slow down their metabolic processes to a minimum to retain resources until conditions are more favourable. Plants may do this when their is a lack of water, while animals, such as the garden dormouse, hibernate, which is also a form of dormancy.

Pertaining to the amount of a particular substance within an organism, either naturally or implanted.

A type of blood circulation system where blood moving away from the heart is seperated from blood moving towards it, common in mammals and birds.

The structure of DNA.

Pertaining to alleles that possess two recessive alleles, resulting in expression of the recessive phenotype.

The amount of time between successful cell divisions.

Down's Syndrome

A genetic defect caused by non-disjunction at meiosis in humans resulting in one extra chromosome (3x21 chromosomes) in the carrier. Sufferers express characteristics such as heart defects, mental retardation and stunted growth.

Commonly known as fruit fly, this small insect is most commonly used in genetics experiments due to their fast reproductive cycle and their compact size for large scale experimentation.

Substances that are capable of altering natural biological processes, with their manipulating nature used in medicine as a corrective measure against deviances from these normal biological processes.

A term of measurement used to measure biomass, as opposed to fresh mass. Dry mass is a more reliable indicator of biomass due to the fact that fresh mass measurements are dependant on fluctuating water concentrations in the biological material measured.

Tubes responsible for carrying liquids.

Part of the small intestine that is connected to the stomach, this is the area of the digestive system that completes most of the food breakdown passed on from the stomach. Enzymes promote the breakdown of foodstuffs in the duodenum, while the large surface area that it presents allows large scale absorption of materials into the bloodstream.

A type of chromosome mutation where part of the chromosome is replicated. This can sometimes be dangerous, though this type of mutation is not as severe as others such as deletion mutations.

A disease in elm trees caused by a fungi which blocks the xylem tissues of the tree, effectively cutting off transport of water around it.

A condition where the size of an organism is substantially lower than the species average, usually as a result of low growth hormone production.

A chromosome consisting of two sister chromatids joined at a centromere.

Breathlessness.