IGCSE Biology Vocabulary Flashcards
movement
an action by an organism or part of an organism causing a change of position or place
respiration
the chemical reactions in cells that break down nutrient molecules and release energy for metabolism
sensitivity
the ability to detect or sense stimuli in the internal or external environment and make appropriate responses
growth
a permanent increase in size and dry mass by an increase in the cell number or cell size or both
excretion
removal from organisms of the waste products of metabolism, toxic materials, and substances in excess of requirements
nutrition
taking in materials for energy, growth, and development
reproduction
making more of the same kind of organism
species
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
tissue
a group of cells with similar structures, working together to perform a shared function
organ
a structure made up of a group of tissues, working together to perform specific functions
organ system
a group of organs with related functions working together to perform body functions
diffusion
the net movement of particles from a region of their higher concentration to a lower concentration down a concentration gradient, as a result of random movement
osmosis
the net movement of water molecules from a region of higher water potential (a dilute solution) to a region of lower water potential (a concentrated solution) through a partially permeable membrane
active transport
the movement of particles through a membrane fro ma region of lower concentration to a region of higher concentration using energy from respiration
catalyst
a substance that increases the rate of a chemical reaction and is not changed by the reaction
enzyme
a protein that functions as a biological catalyst
photosynthesis
the process by which plants manufacture carbohydrates from raw materials using energy from light
limiting factor
something present in the environment in such short supply that it restricts life processes
ingestion
taking substance 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 small food molecules and ions through the walls of the intestine into the blood
assimilation
movement of digest food molecules into the cells of the body where they are used, becoming part of the cells
egestion
passing out of food that has not been digested or absorbed, as feces, through the anus
transpiration
the loss of water vapor from plant leaves by evaporation of water at the surfaces of mesophyll cells followed by diffusion of water vapor through the stomata
translocation
the movement of sucrose and amino acids in phloem from regions of production to regions of storage (source) or regions where they are used in respiration or growth (sink)
source
region of the plant from which sucrose or amino acids are being transported
sink
region of the plant to which sucrose or amino acids are being transported
pathogen
a disease causing organism
transmissible disease
a disease in which the pathogen can be passed from one host to another
active immunity
defense against a pathogen by antibody production in the body
passive immunity
short-term defense against a pathogen by antibodies acquired from another individual (mother to infant)
aerobic respiration
the chemical reaction in cells that use oxygen to break down nutrient molecules to release energy