Definitions
Abiotic - factors that are not alive but still affect an organism’s survival (eg water, shelter)
Absolute Magnitude – the brightness of a star when measured as a set distance from the Earth
Absolute Temperature – the temperature relative to absolute zero, measured in Kelvins (K)
Absorption – the conversion of electromagnetic radiation, sound etc into other forms of energy on passing through a medium eg light going through something loses intensity because of scattering and/or absorption
Acceleration – a change in speed of an object caused by force acting on it, measured in m/s2
Alkali Metals – hydrogen, lithium, sodium
Allotropes - different forms of the same element but with different physical properties because the atoms are arranged in a different way, they react to form the same chemical products
Ammeter - an instrument that measures electric current in amperes
Anion – a negatively charged atom. (ie has more electrons than usual)
Anticline – a fold in an inverse “U” shape
Antigen – a cell that counter attacks pathogens
Apparent Magnitude – brightness of a star when viewed from Earth
Atom - the smallest particle of a type of matter that has the same features as that type of matter
Atomic Number - the number of protons in the nucleus of an atom
Big Bang – theory proposes that space & time came into existence due to an explosion 13 billion years agos
Binary Stars – a couple of stars that revolve around each other
Biomass - the mass of all the living things in the environment
Biotic - living things that directly affect the survival of an organism (eg predators)
Black Dwarf – a cooled and black crystalline white dwarf star
Black Hole – a massive star that continually collapses on itself
Catalyst – a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change
Cation – a positively charged atom (ie it has fewer electrons than usual)
Codon – a 3 base sequence that codes for an amino acid
Combustion – the reaction caused by an oxidiser and fuel to create energy
Commensalism - a relationship where one organism benefits and the other is unaffected
Community - all the plants and animals that live in the environment
Compound - a pure substance made of 2 or more different types of atoms that are chemically joined in a fixed ratio
Continental Drift – the widely accepted view that the continents of the Earth are drifting across the globe’s surface. Evidence includes: the earth’s crust is continually moving at rates of several cm/yr, geometric fit of the continents, most earthquakes & volcanoes occur where plate boundaries meet.
Convergent Evolution - the process whereby organisms not closely related independently evolve similar traits as a result of having to adapt to similar environments
Convergent Plate Movement – 2 plates colliding. The oceanic plate moves under the continental one, this is called subduction. When both are oceanic, one will be pushed under the other. When both are continental, they will be pushed upwards forming mountain ranges.
Covalent Bonding – when 2 atoms share an electron
Current – a measure of the no. of electrons that flow in a given time, measured in amperes (A)
Cyclones – a low pressure wind movement going anti-clockwise in the Northern Hemisphere; formed when sea temperatures are high, or when air rises rapidly around the eye/centre
Decomposer - an organism that breaks down dead things in the environment
Diffraction - The bending or spreading of waves when they meet an obstruction.
Diploid Number – normal number of chromosomes in body cells
Displacement – distance from starting point
Divergent Plate Movement – 2 plates moving apart
Divergent Evolution - occurs when two or more biological characteristics have a common evolutionary origin but has moved apart over time
Dyke – an intrusion of the sedimentary strata
Earthquakes – occur because of convection currents in the asthenosphere, and gravitational forces pulling heavy plate edges downward at subduction zones.
Ecosystem - is a part of the Earth where plants and animals live and interact with the environment
Electromagnetic Radiation – Radiation consisting of electric and magnetic waves that travel at the speed of light
Element - a pure substance made of only 1 type of atom that can’t be broken down any further
Endocrine System – a control and coordination system that produces chemical messengers called hormones in ductless glands
Environment - all factors around an organism that affect its chances of survival
Enzyme – a protein that act s as catalyst in biochemical reactions
Epicentre - is the point on the Earth's surface that is directly above the point where an earthquake or other underground explosion originates
Evolution – the idea that all organisms pre-existed from other organisms and have changed to suit the environment; a change in species over time
Fission – when an atom is split into 2 or more parts, releasing energy
Focus – site of the earthquake (could be in any layer of the earth)
Fold – a wavelike form in layered rock that is caused by lateral pressure in parts pf the earth’s crust
Force – an agency that tends to change the momentum of an object
Friction – a force that opposes motion when surfaces move over each other
Fusion – the process of combining atoms to become larger
Galaxy – vast collections of stars that are held together by gravitational force
Gamete – a sex cell (eg ova/ovum or sperm)
Gene – a length of DNA that contains a sequence of bases that code for one protein
Genome – the sequence of bases in the DNA or RNA of a living thing
Genotype – the genetic composition of an organism
Group Number - the number of electrons in the outer shell
Habitat - the place in which a plant/animal lives
Half Life - the time it takes it takes for half a radioactive atom to decay
Halogens – fluorine, chlorine, bromine
Haploid – half the diploid, this only happens in the gamete
Hormones – chemical messengers in the bloodstream that stimulate certain bodily organs
Indicator – a substance used to show the presence of a chemical substance or ion by its colour
Ion - an atom that has gained or lost an electron; thus having a positive/negative charge
Ionic Bonding – when atoms exchange electrons so both become ions
Isomer - when elements form in a different sequence, but still contain the same elements in the same ratio
Isotope - an atom that has the same number of protons in its nucleus as other varieties of the element but has a different number of neutrons
Karyotype – chromosomes that can be cut and arranged into 23 pairs
Lateral Slipping Plate Movement – when 2 plates slide past each other, when the pressure from all this is released, an earthquake is formed.
Light Year – the distance light travels in one Earth year (light travels at 300,000km/sec)
Light Telescope – an instrument that gathers & magnifies light so that distant objects can be studied with better resolution
Load - an energy converter
Longitudinal -
Luminosity - the amount of energy radiated into space per second by a star
m-RNA – a carrier molecule that carries DNA codes
Magnitude – a measure of the relative brightness of a star or other celestial object
Mass Number - the total number of neutrons and protons in a nucleus
Matter – anything that occupies space and has mass
Meiosis – special cell division that occurs to produce sex cells that have half the normal chromosome number
Metalloids - elements that have both non-metal and metal properties (eg Boron, Silicon etc)
Mitosis – normal cell division, in which a cell divides to produce 2 exact copies
Molecule - a group of 2 or more atoms
Mutation – a mistake in the copying of DNA
Mutualism - means that other organisms are adapted to live together; both depend on the other
Nebula – a massive cloud of gas and dust caused by a supernova
Neutralisation – the process in which an acid reacts with a base to form a salt and water
Neutron Star – same as pulsar
Noble Gases – neon, argon, xenon
Non Metals – hydrogen, helium, fluorine
Normal Fault - one plate moves up whilst the other moves downwards; away from each other
Nova – a star that over a period of a few weeks becomes brighter, then returns to normal brightness
Nuclear Energy – energy that binds nuclear particles such as protons and neutrons into the nulceus
Nuclear Fission - the splitting of an atomic nucleus, it occurs when a neutron splits the nucleus of an atom eg U 235, C 14
Nucleotides – the basic components that make up a DNA molecule (ie a phosphate, sugar and nitrogenous base – A, C, G, T)
Ohm’s Law - the electric current in metallic conductors is proportional to the voltage drop across the conductor (eg if the voltage was doubled, so is the current)
Organism - an individual in a species
Ovary – a female egg-producing reproductive organ
Parallel evolution - is the independent evolution of similar traits, starting from a similar ancestral condition due to similar environments or other evolutionary pressures
Parasitism - a relationship where one organism benefits and the other is harmed
Pathogen – a disease-causing micro organism
Period Number - number of shells containing electrons
Phagocytes – a type of white blood cell that engulfs and destroys bacteria
Phenotype – the way living things appear and function
Plate Tectonics – the theory that the 10 plates cause most major geological activities. Evidence includes: geometric fit of continents, matching fossils from the same time period, lots of seismic, volcanic, geothermal activity along the boundaries.
Population - a group of organism that belongs to the same species and lives in the same area
Potential Difference – the energy used by each part of the circuit, measured in volts (V)
Precipitation – the formation of solid from 2 solutions
Protostar – the early stage of forming a star
Protozoan – a single-celled, animal-like organism that causes malaria and dysentery
Pulsar – small and very dense objects that are about as heavy as the sun
Quasar – the centres of violent galaxies that emit huge amounts of energy
Radioactive Decay – the breakdown of large, unstable nuclei
Radioactivity – emission of rays and/or particles doe to the decay of an unstable nucleus
Radioisotope - an atom with an unstable nucleus
Radio Telescope – an instrument that gathers radio waves from distant objects & concentrates them so that they can be studied with better resolution
Rarefaction - The part of a longitudinal wave which is stretched out, where as a compression is the part which is pushed together (longitudinal wave)
Red Giant – a star of great size & brightness that has a relatively low surface temperature
Red Shift – the shift in frequencies of visible spectral lines towards the red end (low frequency) of the electro magnetic spectrum; used as evidence of an expanding universe
Resistance – a measure of difficulty for the current to flow through a conductor, measured in ohms (Ω)
Response - something an animal does that helps it to survive
Refraction - The bending of light as it passes from one medium to another eg, from air to water.
Reverse Fault - one plate moves up whilst the other moves downwards; towards each other, material on the surface overlays each other
Ring Species – normally unrelated species interbreeding around the same region
Scavenger - an animal that eats dead organisms
Semi metals – boron, silicon, arsenic
Sense - used by an animal to detect a change
Species - a group of the same type of living things
Spectrum - The complete range of colours in the rainbow, from short wavelengths (blue) to long wavelengths (red)
Steady State Model – suggests that the universe has always been the way we see it, means it’s infinitely old, no DOB and would never end. Suggests that matter is created all the time, and this forms galaxies which slowly move apart.
Stimulus - the message a plant or animal receives
Subspecies – the rank of an animal immediately below the species
Superconductivity - the disappearance of electrical resistance at very low temperatures
Supernova – a huge explosion that ends the life of a star
Symbiosis - “living together”. The relationships between different organisms
Syncline – a fold in a “U” shape
Territory - the area where an animal gets the things they need to survive
Territorial Behaviour - an adaptation where organisms map out and defend a territory
Thrust Fault – an upward-downward movement where one plate slides over the top of the other
Transcurrent Fault – a general horizontal movement, will be torn apart over time (eg San Andreas fault)
Transition Metals – iron, cobalt, copper, zinc
Tsunami – massive wave movements that are caused by disruptions (earthquakes, volcanic eruptions) of the seabed
Vector – an organism that spreads disease
Velocity – a measure of speed in a fixed direction. Unit – m/s
Volcanoes – a mountain capable of exploding. Forms when there’s a blockage of air vents. This builds up gaseous pressure in the chamber, which the volcano won’t be able to withstand, and eventually, release (ie explode)
Voltmeter - a device that measures the potential difference between two points
Weight – the gravitational force acting on an object, measured in Newtons (N)
White Dwarf – the remaining core of a planetary nebula that is small, heavy & hot.
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