Biology

• Digestion is the breaking down of food

• Respiration is the release of energy from food

• Excretion is the removal of waste products of chemical reactions in the body

• An antagonistic pair is made up of two muscles that cause opposite effects

• Sensory nerves carry messages to the central nervous system. Motor nerves carry messages away from the central nervous system.

• Ovulation is the release of an egg from the ovary.

• Fertilisation is the joining of the sperm and the egg to form a zygote.

• Implantation is the attachment of the embryo to the lining of the uterus

• Pregnancy is the time the baby spends developing in the uterus

• Contraception is the prevention of fertilisation

• Genetics is the study of how traits or characteristics are inherited

• A gene is a section of DNA that can produce a protein.

• Invertebrates are animals that do not have backbones

• Vertebrates are animals that have backbones

• Transpiration is the loss of water from a plant

• The transpiration stream is a flow of water from the roots up through the stem and out of the leaves of a plant

• Photosynthesis is the way in which green plants make food.

• A tropism is the change in growth of a plant in response to an outside stimulus.

• Phototropism is the way a plant changes its growth response to light.

• Geotropism is the way in which a plant changes its growth in response to gravity.

• Sexual reproduction involves two sex cells joining together during fertilisation.

• A gamete is a sex cell

• Asexual reproduction means that new individuals are formed from only one parent.

• Pollination is the transfer of pollen from a stamen to a carpel.

• Fertilisation is the joining of the male and female gametes to form a zygote.

• Dispersal is the carrying of the seed as far as possible from the parent plant

• Germination is the growth of a seed to form a new plant.

• Ecology is the study of the relationships between plants, animals and their environments.

• A habitat is where a plant or animal lives.

• A population refers to all members of that particulars type of a plant or animal living in a habitat.

• A community refers to all the plants and animals in that habitat

• Producers are plants that make their own food.

• Consumers are animals that get their food by eating plants or other animals

• A food chain is a list of living things in which each one is eaten by the next one in the chain.

• Adaptations are structures of habits that living things have which enable them to survive in their habitats.

• Competition occurs when two of more organisms require something that is in short supply.

• Interdependence means that living things depend on each other for survival.

• A line transect is a rope marked at regular intervals and laid out across a habitat to estimate the number of plants present.

• Conservation is the protection and wise management of our natural resources.

• Pollution is any unwanted change to our environment.

• Micro-organisms are small living things

• A parasite is a living thing that gets its food from another living thing.

• A saprophyte is a living thing that gets its food from dead sources.

• Antibiotics are chemicals made by micro – organisms that kill or prevent the growth of bacteria .

• Biotechnology is the use of living things or parts of living things to make useful products.

• A mixture is made up of two or more substances mingled together but not chemically combined.

• Elements are substances made up of only one type of atom.

• Molecules are made up of two atoms chemically combined.

• Compounds are made up of two or more elements chemically combined

• Mixtures contains two or more different substances mingled together but not chemically combined.

• Atomic number is the number of protons (or electrons) in an atom of an element.

• Mass number is the number of protons and neutrons in an atom of an element.

• Isotopes are atoms of the same element which have the same atomic number but different mass numbers.

• An alloy is a mixture of metals

• Corrosion is an undesirable process whereby a metal changes to its oxide or some other compound by combining with oxygen in air.

• An ion is an atom which has lost or gained electrons.

• An ionic bond is the electrical force of attraction between positive and negative ions.

• A covalent bond consists of a pair of electrons shared between two atoms.

• A physical change is a change in which no new substance is formed.

• A chemical change is a change in which at least one new substance is formed.

• A fuel is a substance that burns in oxygen to produce heat.

• Catalysts are substances which alter the rate of a chemical reaction but are not used up themselves.

• Electrolysis is the splitting up of a compound by passing electricity through it.

• A solution is a mixture of a solute and a solvent.

• A saturated solution is a solution that contains as much dissolved solute as possible at that given temperature.

• Crystallisation is the formation of crystals by the cooling of a saturated solution.

• Fuels are substances which burn in oxygen to produce heat energy.

• Hydrocarbons are compounds made up of hydrogen and carbon.

• Polymerisation is the process involving the joining together of many small molecules called monomers to form a large molecule called a polymer.

• Length is the straight line distance between two points in space.

• Mass is the quantity of matter in a body

• Time is the quantity in which change happens.

• Temperature is a measure of how hot or cold a body is.

• Area is the amount of surface that covers a body.

• Volume is the amount of space taken up by a body.

• Area = length x width

• Volume = length x width x height.

• The density of a body is the mass of one unit of volume of a body.

• Density = (mass / volume)

• Speed is the distance travelled by an object in a unit of time

• Velocity is the speed of a body and the direction in which it is moving.

• Acceleration is the change in velocity in a unit of time.

• Speed = distance / time.

• Acceleration = change in velocity / time taken for the change.

• A force gives a body at rest a velocity or makes a moving body change its velocity.

• A force causes a mass to accelerate.

• A change in velocity can be a change in speed or a change in direction or both.

• Friction is a force that opposes the motion of a body when it is in contact with another

• Lubrication is when a material is placed between surfaces of two moving bodies in contact, to reduce friction.

• The weight of a body on the surface of the moon is the attraction between the moon and the body and this is different from the force on the earth.

• The centre of gravity of a body is a point about which the turning effects caused by gravity are balanced. The weight of the body seems to be concentrated at this point.

• A body is in equilibrium if its centre of gravity is not moving and the body is not turning about any point

• A lever is a rigid body that can rotate about a fulcrum.

• The turning effect of a force is called the moment of a force.

• The law of the lever states that when a lever is balanced, the sum of the clockwise moments equals the sum of the anticlockwise moments.

• Pressure is the amount of force acting on a unit area.

• Work done = Force x distance moved in the direction of the force

• Energy is the ability to do work

• Power is the amount of work done in a unit of time.

• Energy is neither created nor destroyed but can be converted from one form to another.

• Heat is a form of energy

• Temperature is a measure of the relative hotness or coldness of a body.

• Increase in pressure raised the boiling point of water.

• The heat that is needed to change the state of a substance is called latent heat.

• Conduction is the transfer of heat through a substance without any overall movement of the substance itself.

• Convection is the transfer of heat through liquids and gases by the mass movement of particles.

• Radiation is the transfer of heat by means of waves that can travel through a vacuum. This is how the heat energy of the sun gets to the Earth.

• Light is a form of energy because it is a wave and waves carry energy.

• A luminous body creates its own light.

• Non – luminous bodies reflect light.

• The breaking up of white light into its different colours is called dispersion.

• The spectrum of light is made up of seven major colours. Red orange yellow green blue indigo and violet.

• Refraction is the bending of light as it passes from one transparent material to another.

• Sound is a form of energy and is produced when bodies vibrate.

• Sound needs a medium to be transmitted.

• The speed of sound is much less than the speed of light.

• A force something that changes the motion of a body.

• A magnetic field is the region of space around a magnet in which certain materials and other magnets will experience a magnetic force.

• A compass is a small magnet or a magnetised needle that is free to move in a protective case.

• Charge exerts force on another charge.

• Voltage = Resistance x Current or V = RI

• Direct current is the flow of charge in only one direction around a circuit.

• Alternating current is current that constantly changes direction.

• A kilowatt – hour is the amount of energy provided when 1 kilowatt of power is used for one hour.

• Cost = power rating in kW x unit cost x time in hours.

• Electronics is the controlling of devices by directing small amounts of current around circuits.