definitions for bio

• movement


  an action by an organism or part of an organism causing a change in position or place
• respiration


  the chemical reactions in cells that break down nutrient molecules and release energy for metabolism
• sensitivity 


  ability to detect or sense stimuli in the internal or external environment and to make appropriate responses
• growth


  permanent increase in size and dry mass
• excretion


  removal from organisms of waste products of metabolism and substances in excess of requirements
• reproduction


  processes that make more of the same kind of organism
• nutrition


  taking in of materials for energy, growth and development
• species


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


  naming species as an internationally agreed system in which the scientific name of an organism is made up of 2 parts, genus and species
• morphology


  study of form and outward appearance of organisms
• anatomy


  study of the internal structure, revealed by dissection
• classification systems


  aim to reflect evolutionary relationships
• cell


  basic building blocks of life
• tissue


  group fo similar cells working together to perform a shared function, e.g. bone, nerve, muscle, epidermis, xylem
• organ


  group of specialised tissues, working together to perform a specific function, e.g. stomach, heart, lungs, intestines, brain, eyes
• organ system


  group of specialised organs (with related functions), working together to perform a specific function, e.g. nervous and circulatory system
• diffusion


  net movement of particles from a region of higher concentration to a region of lower concentration down a concentration gradient as a result of their random movement
• osmosis


  net movement of water molecules from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution) through a partially permeable membrane
• active transport


  the movement of particles through a cell membrane from a region of lower concentration to a region of higher concentration against a concentration gradient using energy from respiration, and protein carriers.
• catalyst


  substance that speeds up the rate of a chemical reaction and is not changed by the reaction
• enzyme


  proteins involved in all metabolic reactions where they function as biological catalysts
• photosynthesis


  the process by which plants synthesise carbohydrates from raw materials using energy from light
• starch 


  energy store
• cellulose


  build cell walls
• glucose


  using in respiration to provide energy
• sucrose


  transport on the phloem
• nectar


  attract insects for pollination
• limiting factor


  something present in the environment in such short supply that it restricts life processes
• ingestion


  taking in of substances e.g. food and drink into the body through the mouth
• mechanical digestion


  breakdown of food into smaller pieces without chemical change to the food molecules
• chemical digestion


  breakdown of large insoluble molecules into small soluble molecules
• absorption


  movement of nutrients from intestines to blood
• assimilation


  uptake and use of nutrients by cells
• egestion 


  removal of undigested food from the body as feces
• transpiration


  loss of water vapour from plant leaves by evaporation of water at the surfaces of the mesophyll cells into the air spaces followed by diffusion of water vapour through stomata
• translocation 


  movement of sucrose and amino acids in phloem from source to sink
• circulatory system


  system of blood vessels with a pump and valves to ensure one way flow of blood
• activity of the heart monitored by

  ECG, pulse rate, and listening to sounds of valves closing
• heart arteries and veins

  vena cava, pulmonary vein, aorta, pulmonary artery
• kidney


  renal artery (oxygenated blood from the heart to the kidneys)

  renal vein (carries deoxygenated blood from the kidneys to the heart)