BIOLOGY DEFINITION

• Movement


  An action by an organism or part of an organism causing a change of position or place
• Sensitivity


  The ability to detect or stimuli in the internal or external environment and to make responses
• Growth


  A permanent increase in size and dry mass by an increase in size, number or cell size or both
• Excretion


  The removal from organisms of the waste products of metabolism, toxic materials and substances in excess of requirements
• Species


  A group of organisms that can reproduce to produce fertile offspring
• Binomial system


  An Internationally agreed system in which the scientific name of an organism is made up of two parts showing the genus and species
• Diffusion


  The net movement of molecules and ions from a region of their higher concentration to a region of their lower concentration down a concentration gradient as a result of their random movement
• Osmosis


  The net movement of water molecules from a region of higher water potential to a region of lower water potential through a partially permeable membrane
• Active transport


  The movement of molecules and ions in and out of the cell through the cell membrane against concentration gradient, using energy from respiration
• Enzymes


  Protein molecules that act as biological catalysts
• Catalyst


  A substance that increases the rate of chemical reactions without being used up or changed
• Photosynthesis


  A process by which plants make carbohydrates from simple raw materials using energy from light
• Balanced diet


  A daily intake of seven nutrients (carbohydrates, proteins, lipids, vitamins, minerals, water and fibers) in a correct amount to provide energy required and raw material for healthy growth and tissue repair
• Ingestion


  Taking of substances into the body through the mouth
• Digestion


  Large insoluble molecules are broken down to small and soluble molecules by mechanical and chemical digestion
• Absorption


  The movement of small and soluble food molecules and ions through the wall of the intestine into the blood
• Assimilation


  The movement of digested food molecules into the cells of the body where they are used and become part of the cells
• Egestion


  Passing out of food that has not been digested or absorbed
• Transpiration


  The loss of water vapour from plant leaves by evaporation of water at the surfaces of the mesophyll cells followed by loss of water vapour through stomata
• Translocation


  The movement of sucrose and amino acids in phloem from the regions of production (source) to regions of storage or regions of utilization in respiration or growth
• Pathogen


  A micro-organism that causes disease
• Transmissible disease


  A disease caused by a pathogen and can be passed from one host to another
• Antigens


  Chemicals found on the surface of the pathogen that are recognised by the body as foreign
• Consumer


  An organism that gets energy by feeding on other organisms
• Primary consumer (herbivore)


  An animal which eats plants
• Secondary consumer (carnivore)


  An animal which eats another animal
• Decomposer


  An organism that gets its energy from dead matter or waste organic materials, they are extremely important because they help to recycle substances
• Biotechnology


  Using living organisms (usually micro-organisms) to make substances that we want
• Genetic engineering


  Changing the genetic material of an organism by removing, changing or inserting individual genes
• Eutrophication


  Reduction in the level of oxygen in water which leads to death of all aquatic life that respire aerobically
• Sustainable resource


  A resource that is produced as rapidly as it is removed from the environment that it does not run out
• Sustainable development


  Development providing for the needs of an increasing human population without harming the environment
• Gene


  A length part of DNA that codes for one protein
• Allele


  A version of a gene or any of two or more alternative forms of a gene
• Haploid nucleus


  A nucleus containing a single set of unpaired chromosomes
• Diploid nucleus


  A nucleus containing two sets of chromosomes
• Mitosis


  A nuclear division which giving rise to two genetically identical cells
• Stem cells


  Un-specialized cells that divide by mitosis to produce daughter cells that can become specialized for specific functions
• Meiosis (reduction division)


  A nuclear division in which the chromosome number is halved from diploid to haploid resulting in formation of four genetically different cells
• Genotype


  The genetic make-up of an organism