Shorthand for cytosine or cysteine.

Caffeine is a diuretic that stimulates the central nervous system, and can be found in cocoa beans.

A substance essential to the diet of animals and plants and is present in and is an important constituent of bones, teeth and shells.

An outdated unit measuring energy and now replaced by the joule unit, one calorie is the amount of heat energy required to hear 1 squared centimetre of water by 1 degree Celsius.

A series of chemical reactions that occur in autotrophic animals (like plants), where organelles called chloroplasts host this reaction. After the photolysis of water, the dark reactions occur in the Calvin cycle. To learn more about photosynthesis and the Calvin cycle check out the tutorial page on photosynthesis.

The biochemist that is best known for his work involving photosynthesis, particularly the thermochemical stage. He investigated the carbon compounds involved in this process to the point where the cycle of .

A drug most commonly used recreationally in many societies which has hallucinogenic properties. Some recent research suggests that cannabis may have medicinal properties in curing / removing symptoms of degenerative diseases.

The protein coat that surrounds the DNA or mRNA of a virus.

A family of organic molecules consisting of carbon (carbo), hydrogen (hydr) and oxygen (ate). This family can range from simple sugards such as glucose and fructose to complex sugars like starch and cellulose.

More info relating to carbohydrates and their role in our diet can be found in the developmental biology tutorial investigating a balanced diet

Carbon

An element that is characteristically in all organic compounds. With a valency of four, carbon can bond with four other atoms. Carbohydrates consists of carbon, hydrogen and oxygen atoms for example, where th.

Also known as carbonic acid gas, or CO^2, carbon dioxide is found to be used in many essential biochemical pathways and biological processes.

An animal that has a staple diet of meat and thus preys on other animals

Pertaining to an organism that contains a genetic mutation which inherits disease, but does not express this phenotype due to the presence of a more dominant gene.

A type of metabolism where more complex molecules are broken into more simple ones, such as glucose in the process of respiration, therefore making respiration a type of catabolism.

Chemicals that are capable of speeding up the rate of a reaction, an example being the function of enzymes to break down organic matter.

One cell is the lowest denomination of life thought to be possible. Most organisms consist of more than one cell, which become specialised into particular functions towards the cause of the organism as a whole. Cells possess many structures inside them that contain and maintain the building blocks of life called organelles. Animal cells and plant cells differ fundamentally.

When young cells develop as a result of cell division, they become differentiated to suit the function they were made for. This is done by the genetic information present in the cell, which will have genes 'switched on' and 'switched off' to determine the function of the cell.

Also known as mitosis and meiosis. Mitosis is cell replication, where two cells that are an exact copy of their parent cell are created. Meiosis is where four gamete cells are created from the parent cell, with half the chromosome compliment.

The point in time where a cell is designated a particular function e.g. xylem, muscle, nerve cell etc.

Also known as the plasma membrane, that has a structure known as the fluid mosaic model. The cell membrane is designed to protect the cell, but also has a regulatory function where it determines what amounts and types of molecules can enter and leave the cell.

Pertaining to cell defense, where cells store information about foreign entities (viruses, bacteria etc) that have attacked the body once before, so that next time round the body (and the cell) is better prepared.

A structure found in the cells of plants and not animals. The cell walls function ranges from withholding the internal environment within the cell as well as protecting the cell and the organism as a whole against external agents that may prove harmful to them.

The nervous system consists of many neural pathways known as nerves, which all are connected to the central nervous system, the 'centre' of its function. Impulses from the brain travel down the spinal cord to their relevant location to execute a command from the brain, while impulses travel back up towards the brain (afferent neurones) informing it of the body's current situation and actions. The brain also acts as a memory storage device for the organism.

The fragment of a chromosome that contains a centromere dividing the chromosome into two distinct areas.

A structure found in chromosomes, the centromere consists of fibres and holds together two chromatids to create the chromosome as a whole.

The potential energy within a given chemical that can potentially be released in a reaction (such as the chemical energy of ATP or glucose).

A chemoreceptor is a type of receptor that differentiates various stimuli by its chemical composition.

A type of taxonomy that classifies organisms in relation to their chemical composition.

A type of cell commonly found in the gills of fish. They play a role in regulating the salt concentration of cells in relation to the external environment, and differ greatly between freshwater and saltwater organisms.

Chlorophyll is a substance most commonly found in plants usually located in chloroplasts. Its primary function is to absorb sunlight for photosynthesis to occur within the plant. Depending on its colour (in this case green), the wavelength of light absorbed will depend on which photosynthetic pigment is absorbing it.

Chloroplasts contain chlorophyll, a photosynthetic pigment used in the process of photosynthesis. The chief structures within the chloroplast are the stroma and granum, which host the photochemical and thermochemical stages of photosynthesis.

On of a pair of duplicated chromosomes that also contains a centromere.

An illustration of the seperation of leaf pigments to determine what pigments are within a particular species. For instance, a plant may possess the pigments chlorophyll a, chlorophyll b, xantophyll and carotene in its photosynthetic leaves, and this in turn can illustrate what colours of light the plant absorbs via comparing the chromatogram to an action spectrum.

The structures found within a cell that contain the genetic information of an organism. This genetic information is DNA or mRNA, deoxyribonucleic acid and messenger ribonucleic acid respectively.

The causality where a chromosome is missing from the new cell created via cell division

Chromosome Marker

A distinct sequence found on a chromosome that helps identify a particular area of it.

The chromosome number of a cell, normally 46 in humans, where 23 pairs of chromosomes make up this number. Genetic mutations can result in varying chromosome numbers to the genome norm, which usually have disadvantageous results.

Homologous chromosomes.

Chyme

The semi-liquid state that food is in after being processed in the stomach, the pre-requisite before it is passed on to the duodenum in the small intestine.

Cilia

Plural of cilium, see cilium.

See Krebs Cycle.

A type of taxon used in classifying organisms deriving from each classes respective phylum. Each class is divided into orders of species to further differentiate unique organisms down to the species level of taxon.

Cloud cover is an abiotic factor, because the presence of clouds blocks out light, and thus has an affect on plants and the rate of photosynthesis they perform, for example. Therefore, cloud cover is an abiotic factor due to its intricate role in the lives of living organisms on or around the surface.

CO2 is the shorthand for carbon dioxide, consisting of one carbon atom and two oxygen atoms.

Pertaining to bacterium with a round appearance.

The sixty-four possible codings from four nucleotides into 64 mRNA sequences 3 nucleotides long.

A cofactor molecule that helps an enzyme catalyse a particular reaction by binding with it.

Relating to the evolutionary changes of different species in relation to one another, particularly that of those who are related in some way, such as plants and herbivores.

The attraction of alike molecules, such as water.

The hypothesis used to explain how water can travel upwards against gravity in a plant. Transpiration is believed to play a large factor in this, where the cohesive water travels upwards replacing water lost.

The local name given to a particular species of a plant, as opposed to the scientific Latin or Greek name, which is used universally.

The ideal conditions for an organism to survive and grow.

The standard arrangement of bases in nucleotides in relation to their opposite pairing, such as thymine being paired with adenine and Diffusion A substance consisting of more than one atom or one type of element, for instance, oxygen is an element while carbon dioxide (one carbon for every will result in this substance moving along a concentration gradient until the concentration of the two areas becomes equal.

This movement of concentration along a gradient is common in many biological processes, which are elaborated upon in the cell biology tutorial involving the biological cell which mentions the various ways how substances can pass through a cell membrane.

The degree of likeness in a phenotype of organisms in a same species, such as people with the same colour of eyes or hair.

The availability of electricity being able to pass through a given substance.

Pertaining to the same species.

Reference to occurrences that happen before birth, and are caused by the environment, i.e. they are not inherited.

The long term preservation and protection of the environment, ensuring that the natural habitat of an area can be maintained while genetic diversity of a species can remain by sustaining its natural environment.

An organism that consumes another organism as food as a mean of energy.

Relating to diseases that are capable of spreading by contact with pathogens from another infected organism.

A foreign species of a given environment where the species is not in its natural habitat, and therefore foreign to the new environment also.

The moving of tectonic plates under the Earth's surface, which is constantly moving the land masses of the world away or closer to one another. It is believed continental drift is responsible for the way in which related organisms are distributed today and can explain why geographical barriers (the splitting of land masses) created new species.

See Convergent Evolution.

A form of evolution where similar adaptations have occurred in unrelated species.

The five digit toes and hands humans have are similar to that other mammals and birds, who have evolved from differing evolutionary chains, though have attained the same physiological characteristic due to its advantages regardless of the evolutionary chain.

A specific type of cambium devoted to the production of bark.

Found on the exterior of the eye where light is able to pass through this epithelial tissue called the cornea. The light that enters the eye is then focused on to the retina.

A type of blood clot occurring in the coronary artery, an essential main artery that supplies blood to the heart.

Blood vessels responsible for carrying oxygenated and deoxygenated blood to and from the heart.

Cotyledon

A storage organ in plants that can absorb nutrients via the angiosperm which in turn provides nutrients to the embryo.

A type of evolution as a result of reproduction between predator and prey. The evolutionary characteristics developed over time via these species prior to this would have been aiming towards a more advantageous .

Peripheral nerves that emerge from the brain that is not part of the spinal cord. These nerves supply the motor pathways between organs in the face and upper body, and are responsible for many of our senses.

The skull in vertebrate animals protecting the brain.

Crista

The fold found on mitochondria that presents a large surface area for aerobic respiration to occur.

Plural of crista.

The return of crop material intended for growth obtained by humans harvesting the plant crop.

The genetic exchange of information in two different plants to reproduce more members of the same species, or a cross of the two.

A process that occurs in meiosis where homologous chromatids exchange genetic information between one another, increasing genetic diversity in the process of it.

Plants are not capable of behavioural responses, though genetically imprinted defensive traits can sometimes help a plant and the long term survival of the species against common enemies. Cyanogenesis is an occurrence in plants that produces a deadly subs.

The living protoplasm part of a cell outside the nucleus that surrounds all other cell organelles outside the nucleus.

One of the four nitrogenous bases of DNA, alongside adenine, guanine and thymine.