Key Words and Meanings - Year 9 Science
  • B1 Cells and B2 Organisation (part 1)
    active transport the movement of substances from a dilute solution to a more concentrated solution against a concentration gradient, requiring energy from respiration 
    alveoli tiny air sacs in the lungs that increase the surface area for gaseous exchange 
    bacteria single-celled prokaryotic organisms 
    diffusion the spreading out of the particles of any substance in a solution, or particles in a gas, resulting in a net movement of particles from an area of higher concentration to an area of lower concentration down a concentration gradient 
    eukaryotic cells cells from eukaryotes that have a cell membrane, cytoplasm, and genetic material enclosed in a nucleus  
    osmosisthe diffusion of water through a partially permeable membrane from a dilute solution (which has a highconcentration of water) to a concentrated solution (with a low concentration of water|) down a concentration gradient  
    cloning the production of identical offspring by asexual reproduction 
    mitosis part of the cell cycle where one set of new chromosomes is pulled to each end of the cell forming two identical nuclei during cell division 
    stem cells undifferentiated cells with the potential to form a wide variety of different cell types 
    enzymes biological catalysts, usually proteins  
  • C1 Atoms and the Periodic Table; C2 Bonding and Matter
    AtomThe smallest particle of a chemical element that can exist. 
    ElementEach of more than one hundred substances that cannot be chemically interconverted or broken down into simpler substances and are primary constituents of matter. Each element is distinguished by its atomic number, i.e. the number of protons in the nuclei o 
    CompoundA thing that is composed of two or more separate elements; a mixture. 
    MixtureA substance made by mixing other substances together. 
    SeparateDivide into constituent or distinct elements. 
    NeutronA subatomic particle of about the same mass as a proton but without an electric charge, present in all atomic nuclei except those of ordinary hydrogen. 
    ProtonA stable subatomic particle occurring in all atomic nuclei, with a positive electric charge equal in magnitude to that of an electron. 
    ShellElectron shell - a grouping of electrons surrounding the nucleus of an atom; "the chemical properties of an atom are determined by the outermost electron shell" group, grouping - any number of entities (members) considered as a unit. 
    IonAn atom or molecule with a net electric charge due to the loss or gain of one or more electrons. 
  • P1 Energy and P6 Waves
    EnergyIn physics, the ability to do work. Objects can have energy by virtue of their motion (kinetic energy), by virtue of their position (potential energy), or by virtue of their mass (see E = mc2). 
    WavesIn physics, any regularly recurring event, such as surf coming in toward a beach, that can be thought of as a disturbance moving through a medium. Waves are characterized by wavelength, frequency, and the speed at which they move. 
    TransformThe act, state or process of changing, such as in form or structure; the conversion from one form to another; Any change in an organism that alters its general character and mode of life; post-natal biological transformation or metamorphosis. 
    TransferThe conversion of one form of energy into another, or the movement of energy from one place to another. Solar panels allow for energy transfer from light energy to heat and electrical energy. 
    FuelFuel such as coal, wood, oil, or gas provides energy when burned. Compounds in the body such as glucose are broken down into simpler compounds to provide energy for metabolic processes. Some radioactive substances, such as plutonium and tritium, provide e 
    SustainableThe ability to be sustained, supported, upheld, or confirmed. Environmental Science, the quality of not being harmful to the environment or depleting natural resources, and thereby supporting long-term ecological balance. 
    TransverseA wave that oscillates perpendicular to the axis along which the wave travels. Electromagnetic waves are transverse waves, since the electric and magnetic fields oscillate at a right angle to the direction of motion. 
    LongitudinalRunning lengthwise rather than across. 
    ThermalRelated to temperature. 
    InvisibleUnable to be seen. 
  • P2 Electricity
    CurrentA flow of electricity which results from the ordered directional movement of electrically charged particles. 
    VoltageAn electromotive force or potential difference expressed in volts. 
    ChargeIn physics, charge, also known as electric charge, electrical charge, or electrostatic charge and symbolised q, is a characteristic of a unit of matter that expresses the extent to which it has more or fewer electrons than protons. 
    Electron FlowElectron flow is what we think of as electrical current. We are familiar with two types of electron flow, Direct Current, or DC, and Alternating Current, or AC. 
    InsulatorA substance which does not readily allow the passage of heat or sound. 
    ConductorIn physics and electrical engineering, a conductor is an object or type of material that allows the flow of an electrical current in one or more directions. A metal wire is a common electrical conductor. In metals such as copper or aluminium, the mobile c 
    ElectromagnetA soft metal core made into a magnet by the passage of electric current through a coil surrounding it. 
    Magnetic fieldA region around a magnetic material or a moving electric charge within which the force of magnetism acts. 
    AttractionThe electric or magnetic force that acts between oppositely charged bodies, tending to draw them together. 
    RepulsionThe force that acts between bodies of like electric charge or magnetic polarity, tending to separate them. 
  • B2 Organisation Part 2; B3 Infection and Response
    BacteriaBacteria are microscopic living organisms, usually one-celled, that can be found everywhere. They can be dangerous, such as when they cause infection, or beneficial, as in the process of fermentation (such as in wine) and that of decomposition. 
    VirusBacteria are microscopic living organisms, usually one-celled, that can be found everywhere. They can be dangerous, such as when they cause infection, or beneficial, as in the process of fermentation (such as in wine) and that of decomposition. 
    PathogenA bacterium, virus, or other microorganism that can cause disease. 
    FungusAny of a group of unicellular, multicellular, or syncytial spore-producing organisms feeding on organic matter, including moulds, yeast, mushrooms, and toadstools. 
    ContagiousSpread from one person or organism to another, typically by direct contact. 
    MultiplyIncrease or cause to increase greatly in number or quantity. 
    RespirationA process in living organisms involving the production of energy, typically with the intake of oxygen and the release of carbon dioxide from the oxidation of complex organic substances. 
    PhotosynthesisThe process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a by-product. 
    GlucoseA simple sugar which is an important energy source in living organisms and is a component of many carbohydrates. 
    OxygenA colourless, odourless reactive gas, the chemical element of atomic number 8 and the life-supporting component of the air. 
  • C7 Organic Chemistry; C9 Chemistry of the Atmosphere; C10 Using Resources
    AtmosphereThe envelope of gases surrounding the earth or another planet. 
    FuelFuel such as coal, wood, oil, or gas provides energy when burned. Compounds in the body such as glucose are broken down into simpler compounds to provide energy for metabolic processes. Some radioactive substances, such as plutonium and tritium, provide e 
    RecycleReturn (material) to a previous stage in a cyclic process; re-use. 
    SustainabilityAble to be maintained at a certain rate or level. 
    EnergyIn physics, the ability to do work. Objects can have energy by virtue of their motion (kinetic energy), by virtue of their position (potential energy), or by virtue of their mass (see E = mc2). 
    Waste(of a material, substance, or by-product) Eliminated or discarded as no longer useful or required after the completion of a process. 
    PollutionThe presence in or introduction into the environment of a substance which has harmful or poisonous effects. 
    PolymerA substance which has a molecular structure built up chiefly or completely from a large number of similar units bonded together, e.g. many synthetic organic materials used as plastics and resins. 
    Covalent bondA covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between 
    CrackingIn petroleum geology and chemistry, cracking is the process whereby complex organic molecules such as kerogens or long chain hydrocarbons are broken down into simpler molecules such as light hydrocarbons, by the breaking of carbon-carbon bonds in the prec 

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