Bio Definitions

STUDY
PLAY

Terms in this set (...)

Electrolysis
The breaking down if an ionic compound, molten or in aqueous solution, by the passage of electricity
Relative Atomic Mass Ar
The average mass if naturally occurring atoms of an element on a scale where the 12C atom has a mass of exactly 12 units
Relative Molecular Mass Mr
The sum of the relative atomic masses
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 to make appropriate responses
Growth
A permanent increase in size and dry mass by an increase in cell number or cell size or both
Excretion
Removal from organisms of the waste products of metabolism (chemical reactions in cells including respiration), toxic materials, and substances in excess of requirements
Nutrition
Taking in of materials for energy, growth and development; plants require light, carbon dioxide, water and ions; animals need organic compounds and ions and usually need water
Species
A group of organisms that can reproduce to produce fertile offspring
Binomial System of naming species
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 if a group if 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 if 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 (dilute solution) to a region if lower water potential (concentrated solution), through a partially permeable membrane
Active transport
The movement of particles through a cell membrane from a region if lower concentration to a region of higher concentration using energy from respiration
Catalyst
A substance that increases the rate if a chemical reaction and is not changed by the reaction
Enzymes
Proteins that function ad biological catalysts
Photosynthesis
The process by which plants manufacture carbohydrates from raw materials using energy from light
Limiting factor
Something present in the environment in such shirt supply that it restricts life processes
Ingestion
The taking of substances into the body through the mouth
Mechanical digestion
The breakdown of food into smaller pieces without chemical change to the food molecules
Chemical digestion
The breakdown of large, insoluble molecules into small, soluble molecules
Absorption
The movement of small food molecules and ions through the wall of the intestine into the blood
Assimilation
The movement if digested food molecules into the cells of the body where they are used, becoming part if the cells
Egestions
The passing out of food that has not been digested or absorbed, as faeces, through the anus
Transpiration
Loss of water vapour from plant leaves by evaporation of eater st the surfaces of the mesophyll cells followed by diffusion of water vapour through the stomata
Trabslocation
The movement of sucrose and amino acids in the phloem from regions of production (source) to regions of storage or regions where they are used in respiration or growth (sink)
Pathogen
A disease-causing organism
Transmissible disease
A disease in which the pathogen can be passed from one host to another
Active immunity
Defence against a pathogen by antibody production in the body
Passive immunity
Short-term defence against a pathogen by antibodies acquired from another individual
Aerobic respiration
The chemical reactions in cells that use oxygen to break down nutrient molecules to release energy
Anaerobic respiration
The chemical reactions in cells that break down nutrient molecules to release energy without using oxygen
Deamination
The removal of the nitrogen-containing part of amino acids to form urea
Sense organs
Groups of receptor cells responding to specific stimuli: light, sound, touch, temperature and chemicals
Hormone
A chemical substance produced by a gland and carried by the blood, which alters the activity of one or more specific target organs
Homeostasis
The maintenance of a constant internal environment
Gravitropism
A response in which parts if a plant grow towards IR away from gravity
Phitotrophism
A response in which parts if a plant grow towards or away from the direction from which light is coming
Drug
Any substance taken into the body that modifies or affects chemical reactions in the body
Asexual reproduction
A process resulting in the production of genetically identical offspring from one parent
Sexual reproduction
A process involving the fusion of the nuclei if two gametes (sex cells) to form a zygote and the production of offspring that are genetically different from each other
Fertilisation
The fusion of gamete nuclei
Pollination
The transfer of pollen grains from the anther to the stigma
Self-pollination
The transfer of pollen grains from the anther of a flower to the stigma of the same flower or different flower on the same plant
Cross-pollination
Transfer of pollen grains from the anther of a flower to the stigma if a flower on a different plant of the same species
Sexually transmitted infection
An infection that is transmitted via body fluids through sexual contact
Inheritance
The transmission of genetic information from generation to generation
Chromosome
A thread-like structure of DNA, carrying genetic information in the form of genes
Gene
A length of DNA that codes for a protein
Allele
A version if a gene
Haploid nucleus
A nucleus containing a single set if unpaired chromosomes, e.g. in gametes
Diploid nucleus
A nucleus containing two sets of chromosomes, e.g. in body cells
Mitosis
Nuclear division giving rise to genetically identical cells
Meiosis
Reduction division in which the chromosome number is halved from diploid to haploid resulting in genetically different cells
Genotype
Genetic make-up of an organism in terms of the alleles present
Phenotype
The observable features of an organism
Homozygous
Having two identical alleles of a particular gene
Heterozygous
Having two different alleles of a particular gene
Dominant
An allele that is expressed if it is present
Recessive
An allele that is only expressed when there is no dominant allele of the gene present
Variation
Difference between individuals of the same species
Mutation
Genetic change
Gene mutation
A change in the base of sequence of DNA
Adaptive feature
The inherited functional features of an organism that increase its fitness
Fitness
The probability of an organism surviving and reproducing in the environment in which it is found
Process of adaptation
The process, resulting from natural selection, by which populations become more suited to their environment over many generations
Food chain
Showing the transfer of energy from one organism to the next, beginning with a producer
Trophic level
The position of an organism in a food chain, food web, pyramid of numbers or pyramid of biomass
Food web
A network of interconnected food chains
Producer
An organism that makes its own organic nutrients, usually from sunlight, through photosynthesis
Consumer
An organism that gets its energy by feeding on other organisms
Herbivore
An animal that gets its energy by eating plants
Carnivore
An animal that gets its energy by eating other animals
Decomposer
An organism that gets its energy from dead or waste organic material
Population
A group of organisms of one species, living in the same area, at the same time
Community
All of the populations if different species in an ecosystem
Ecosystem
A unit containing the community of organisms and their environment, interacting together
Genetic engineering
Changing the genetic material of an organism by removing, changing or inserting individual genes
Sustainable resource
One which is produced as rapidly as it is removed from the environment so that it does not run out
Sustainable development
Development providing for the needs of an increasing human population without harming the environment
Speed
total distance ÷ total time