Term | Definition |
Distal tubule | part of the nephron where water is extracted |
DNA | abbreviation for deoxyribonucleic acid; the molecule which makes up the genetic material of the chromosmes |
Effector | Part of an organism which produces a response (e.g. heart, diaphragm). |
Ectotherm | organism that changes its body temperature by using heat from the environment; plants and most animals except for mammals and birds are ectothermic |
enantiostasis | the maintenance of metabolic and physiological functions in response to variations in the environment. |
endocrine system | hormonal system that produces internal secretions which act upon organs |
endotherm | animal that regulates its body temperature using heat generated by its metabolism; mainly birds and mammals are endothermic |
enzyme | a highly specialised cellular protein that reduces the amount of energy required to initiate a chemical reaction, thereby increasing the speed of reactions; the names of enzymes often end in -ase (e.g. cellulase, which digests cellulose). |
Eukaryotic | Cells which have their genetic material (chromosomes) inside a nucleus bounded by a membrane and which have other membrane-bound organelles; includes cells of protists, fungi, animals and plants. |
Endocrine System | The system of glands that secrete hormones |
Evaporative cooling | Removing heat from the body by changing liquid water to water vapour using heat from the skins surface (eg. sweating) or from respiratory surfaces (eg. panting). |
Excretion | The elimination of harmful and unwanted products of metaoblism. |
Excretory organs | Organs involved in the removal of wastes (kidneys, lungs, skin) |
Gene | A unit of inheritance, usually part of a specific DNA molecule (chromosome) |
Glomerulus | A bunch of capillaries found in the vertebrate kidney. |
Activation Energy | The energy necessary to start a chemical reaction |
Active Transport | Movement of substances across a membrane by a process requiring expenditure of energy |
Ambient | Environmental or surrounding (eg.ambient temperature) |
Ammonia | Main nitrogenous waste product of bony fish; excreted diluted in large amounts of water |
Angiosperms | Flowering plants |
Artery | Blood vessel which carries blood away from the heart |
Bowman's Capsule | The capsule at the end of the vertebrate kidney which contains the glomerulus |
Buffer | A solution of two or more chemicals which prevent marked changes in hydrogen ion concentration (pH) when either an acid or base (alkali) is added to the system |
Cambium | Group of cells which divide to form new xylem and phloem cells |
Capillary | Microscopic blood vessels with walls one cell thick, across which materials are exchanged between blood and tissues |
Cell | Smallest unit of life capable of reproducing itself |
Chromosome | Structure made up of genetic material (DNA) and protein found mainly in the nucleus |
Cohesion | Attraction between molecules of water |
Concentration | The amount of a substance in a specific amount of mixture or solution. Normally expressed as weight per unit volume (eg. 25 grams of salt per litre of water; 25g/L) or as molarity |
Denatured | Structural change in proteins |
Diffusion | Movement of particles in gases, liquids or solutions from where they are more concentrated to where they are less concentrated |
Stomates (stomata) | Holes(pores) in the leaves of plants. These pores are controlled by two guard cells which regulate the loss of water from the leaves(transpiration) |
Temperature Gradient | Difference in temperature. Heat energy flows from an area of higher temperature to one of lower temperature. |
Thyroid Gland | Endocrine gland in the throat area which produces thyroid hormones. |
Thyroid Hormones | Hormones involved with regulating the level of body metabolism |
Thyroid Regulating Hormone | TSH; hormone released by the pituitary gland which controls the functioning of the thyroid gland |
Tension | Part of the transpiration-tension-cohesion theory of water movement in xylem tubes; it refers to the 'pulling' of water molecules from the roots to the leaves by negative pressure |
Tissue | A group of cells, usually of similar type, found in a multicellular organism having a specific |