Alkaloid: a nitrogen containing substance found in plants.
Angiosperm: a flowering plant which has its seeds enclosed within an ovary. gymnosperms hold their seed in cones.They originated during the Cretaceous.
Caries: holes in teeth.
Carnosaur: a general term describing all flesh-eating dinosaurs.
Cataract: a medical condition, in which the lens of the eye becomes cloudy and therefore sight is lost.
Catastrophism: the view that the earth is influenced by a sequence of major events that upset the everyday processes, often with dynamic results. Cretaceous: the time period between 140 and 65 million years ago.
DNA: a substance in the chromosomes of cells which stores the genetic information.
Endothermic: warm-blooded creature, such as the mammals.
Entropy: a measure of the disorder of the molecules in substances. Large organisms are seen to be more ordered than small organisms.
Epidemic: an outbreak of a disease, which spreads rapidly through a community.
Galactic Plane: this refers to the fact that the stars of our galaxy are aligned into a relatively flat plane.
Gradualism: the view that the processes and products on the Earth are steady and never changing. A favourite phase is that 'the present is the key to the past'.
Gymnosperm: a plant which holds its seeds in cones.
Radiation: the emission of particles which can penetrate into materials and skin, and have the potential to cause genetic damage.
Regression: the retreat of the sea from land areas.
Supernova: a star which is very bright due to an explosion disrupting its structure.
Tertiary: the time period between 2.5 and 65 million years ago. By the start of the Tertiary the dinosaurs had become extinct.
Transgression: an incursion of the sea over land areas, due to an increase in the relative sea-level height.