ADAPTION In order to help them survive, animals and plants have developed special features to help them fit into their habitat. These special features are called adaptions (examples: Fish have a streamlined body to help them move through the water, camels have large feet to stop them sinking into the sand. Frogs have webbed feet to help them swim.
AIR Air is the mixture of gases that surround the Earth. Air consists of nitrogen (about 78%), oxygen (about 21%), argon (about 1%) and a variety of other gases (including carbon dioxide, helium and water vapour).
Uses for air: Supports Gliders, planes and parachutes. Needed for things to burn. Kites. Blows sailing boats along.
Air does have weight. There is no air on the Moon
AIR PRESSURE It is the moving particles continuously colliding against the edge of a container that causes the pressure in a gas.
The pressure can be increased By squashing the particles closer together (eg pumping up a tyre or blowing up a balloon or By warming the gas. This makes the particles vibrate faster (this is why a balloon expands when heated) (See ATMOSPHERIC PRESSURE)
AIR RESISTANCE Air resistance happens when air tries to slow down a moving object (like a parachute or car). Another name for air resistance is drag. It is a kind of friction.
A streamlined object has only a little air resistance.
ALGAE Single celled plants. Reproduce asexually by binary fission. Live in wet places. Have no leaves or roots.
ALIMENTARY CANAL (gut) The tube that links the mouth to the anus down which food travels.
ALKALI A liquid with a pH value greater than 7
Alkalis i feel soapy to touch ii will neutralise an alkali iii turn RED litmus indicator BLUE
examples: washing soda (sodium carbonate), caustic soda (sodium hydroxide), ammonia soln., garden lime (calcium hydroxide), indigestion mixture (eg magnesium hydroxide).
Alkalis are caustic and can burn your skin. Alkali in your eyes is particularly dangerous.
ALUMINIUM Aluminium is very light metal. It is used to make kitchen foil, saucepans and sometimes good quality bicycle frames). Aluminium is a good conductor of heat and electricity.
AMMETER An instrument used for measuring current. It is placed in series with the conductor being tested and has a very LOW resistance.
AMNION A water filled sac (containing AMNIOTIC FLUID) that helps support and protect the developing embryo.
AMPHIBIANS One of the VERTEBRATES. An animal that lays soft jelly covered eggs in water. Have smooth moist skin. Adults live on land or in water. Young live in water and go through metamorphosis. e.g. frog.
AMPLITUDE The size of a wave. The amplitude of a sound wave determines what its VOLUME will be.
ANNELIDS Segmented worms with bristles on each segment e.g. earthworm or leach.
ANTAGONISTIC MUSCLES Antagonistic muscles are muscles that work in pairs. An example of antagonistic muscles are the biceps and triceps. The biceps lift the arm up and triceps pull it down. When the biceps contract the triceps relax and visa versa,
ANTHER Male part of a flower. Where pollen is made.
ARACHNIDS Animals that have 4 pairs of legs, 2 parts to the body eg spider, scorpion.
ARTERIES Carry blood away from the heart.
ARTHROPODS Animals that have many pairs of jointed legs and an exoskeleton. The arthropods are divided into several smaller groups eg insects, arachnids and crustaceans.
Examples: woodlouse, spider, fly.
A form of reproduction where NO fertilization required. Examples of asexual reproduction:
i) Production of spores in non-flowering plants eg moss, and fungi.
ii) Budding eg in cactus III) runners eg in the strawberry)
iv) Tubers eg in potato).
v) Binary fission in single cells eg in amoeba (a single-celled animal) or in algae (single-celled plants).
The way all individual cells multiply. Disadvantage: daughter cells identical to parent cells. Advantage: A quick process. Rapid colonisation.
ATOM The smallest possible part of any substance. Some substances only have one kind of atom and these are called elements.
Compounds consist of at least two different kinds of atom.
The smallest atom is a hydrogen atom.
BACTERIA Bacteria are microscopic organisms that can be found anywhere. Some bacteria are helpful like those found in the soil that make things rot or the bacteria used to turn milk into yogurt. Some are harmful and can make us ill, causing stomach upset or a sore throat. (See micro-organism).
BALANCED DIET Our diet is what we eat. A balanced diet is eating all the nutrients but in the right amounts.
A balanced diet needs to include carbohydrate (for energy), Protein (for growth), vitamins and minerals (to keep us healthy) along with fibre and water. (see Diet)
BIRD One of the VERTEBRATES. A warm blooded animal that lays hard-shelled eggs on land. Bodies covered in feathers eg thrush.
BLADDER Organ in a human that stores urine. Urine leaves the bladder through a tube called the URETHRA. In males the urethra leaves the body through the penis.
BLOOD A fluid in our body that consists of a clear watery liquid known as plasma and a variety of other larger particles eg
red blood cells: these carry oxygen around the body and give the blood its red colour.
white blood cells: these help fight disease
platelets: very small cells that help the blood clot
Uses for blood:
i) Transports food and oxygen to the cells.
ii) Transports waste away from the cells.
iii) Helps protect the body from infection.
iv) Helps regulate the body temperature (37°C)
BLOOD VESSEL A tube that carries blood around the body. Large blood vessels are called arteries or veins. Small ones are called capillaries. Arteries carry blood away from the heart and veins carry blood back towards the heart.
BOIL A liquid boils when it gets hot enough so that it evaporates inside (forming bubbles) as well as at the surface.
BOILING POINT The boiling point of a liquid is the temperature at which it starts to boil.
The boiling point of water is 100°C
BRAIN Controls and coordinates all the major functions of the body. Where all the nerves meet
BUNSEN BURNER A piece of apparatus that burns gas and is used to heat apparatus. It has an air hole that controls the flame temperature by regulating the flow of air into the burner. When the air-hole is open: A hot, blue, roaring flame. When the air-hole is closed: A cooler, smoky, luminous yellow flame. Not used to heat apparatus as it is very sooty.
BURN When something burns it reacts with oxygen giving off heat and light.
Burning is an example of a permanent change.
CAPILLARY ATTRACTION A force which drags liquids up fine holes or cracks. It is what causes porous objects soaking up water and allows blotting paper and towels to absorb
CARBOHYDRATE Carbohydrates are starch or sugar like sweets, bread, pasta.
Carbohydrates provide us with energy.
Carbohydrates contain the elements carbon, hydrogen and oxygen.
CARBON Carbon is one of the chemical elements. All living things contain carbon.
Carbon is usually black. Coal, charcoal and soot are made mostly of carbon. When you ‘burn’ a piece of toast you are left behind with carbon. Diamond and graphite are both made of pure carbon. When carbon burns it forms carbon dioxide gas.
CARBON DIOXIDE Is a colourless gas used by plants during photosynthesis and breathed out by humans as a waste product.
It is the gas that forms the bubbles in fizzy drinks and is also sometimes put in fire extinguishers.
Carbon dioxide is formed when carbon (or any substance containing carbon, like coal or wood) is burnt.
There is a small amount (0.03%) of carbon dioxide in the atmosphere which causes rain water to become slightly acidic.
The test for carbon dioxide is to bubble it through lime-water which turns cloudy.
Carbon dioxide is a compound of carbon and oxygen and has the formula CO2
CARNIVORE An animal that eats only meat. (Carnivorous) eg thrush, pike, ladybird
CELL The basic unit of all life. All cells contain a NUCLEUS, CYTOPLASM , MITOCHONDRIA AND A CELL MEMBRANE. Plant cells also have a CELL WALL, a LARGE VACUOLE and sometimes CHLOROPLASTS.
CELL A cell is another name for a battery. A battery would normally be several cells joined together. The cell provides the chemical energy to push the electric current around a circuit
(See Circuit symbols)
The living outer boundary of the cell. The membrane is selective in allowing what passes through it (into or out of the cell).
Cells build up into tissues, tissues into organs and organs into organisms. Found in ALL cells.
CELL WALL The dead, outer edge to the cell. gives the cell strength. Made of cellulose.
Found ONLY in plant cells.
CHANGE STATE Changing state means changing from a solid to a liquid to a gas>
This is usually done by heating or cooling it.
Melt = Changing from a solid to a liquid (by heating it)
Evaporate =Changing from a liquid to a gas or vapour (by heating it)
Condense =Changing from a gas to a liquid (by cooling it down)
Solidify (or freeze) = Changing from a liquid to a solid (by cooling it down)
Sublime = All examples of changing state are reversible changes.
CHARACTERISTIC Anything about of animal or plant inherits from its parents is a characteristic
eg. Characteristics of a shark: streamlined body, sharp teeth
Characteristics of a duck: webbed feet, waterproof feathers
When a new substance is formed and a chemical reaction has taken place.
Examples of a chemical reaction are: DECOMPOSITION, COMBINATION, COMBUSTION, RUSTING, PHOTOSYNTHESIS, OXIDATION and NEUTRALISATION
Signs that a chemical change is taking place are:
i. Heat given out ii. Colour change
A chemical change will usually be permanent.
eg Burning magnesium (to form magnesium oxide)
Any process where a new substance is formed (see Chemical Change)
CHLOROPLASTS The part of a plant cell where PHOTOSYNTHESIS is carried out. Found only in certain plant cells above ground. Chloroplasts contain a chemical called chlorophyll which makes them look green. (see cell)
CHORDATES Animals with a backbone. Have an internal skeleton. eg Lion, snake, frog.
CHROMATOGRAPHY Chromatopgraphy is a way of separating a mixture of coloured dyes or pigments such as found in ink.
For example the green ink found in a green felt tip pen might be made of a mixture of blue and yellow ink and chomatography will show us which colours were actually used.
Jelly-fish/sea anemones. Have central mouth surrounded by stinging tentacles eg Portuguese Man of War
COLD-BLOODED Animals whose body temperature alters with the temperature of the surroundings eg fish. All animals except for birds and mammals are cold blooded.
COMBUSTION Another name for BURNING. A combustible material is one that burns easily.
Products of combustion: the chemicals produced when something is burnt. eg. The products of combustion when wax is burnt are carbon dioxide and water.
COMMUNITY A collection of all the animals and plants that live in a particular area.
COMPOUND The substance formed when two or more elements are chemically combined together.
eg HYDROGEN (element) + OXYGEN (element) = WATER (compound).
Other compounds: Copper sulphate, magnesium oxide, calcium carbonate
Note: the elements in a compound cannot be separated without a chemical reaction taking place.
CONDENSE Condensing is what happens when a gas turns to a liquid due to being cooled down.
For example if steam touches a cold mirror it will condense and turn to drops of water. (See Change of State). Condensing is a reversible change.
CONSUMER Consumers are the animals in a food chain (Plants are called producers)
The first animal in a food chain is called a primary consumer
The second animal is called a secondary consumer.
Example food chain
Grass → rabbit → Fox
(producer) → (Primary consumer) → (secondary consumer)
COPPER Copper is pink metal. It is a very good conductor of heat and electricity.
It is the metal that wires are made from. It is a metallic element.
CRUSTACEANS Animals that usually have 5 pairs of legs, eg crab, woodlouse. Belong to the phylum of Arthropods.
The process for obtaining the solute from a solution by warming the solution until crystals start to appear and then letting the solution cool.
eg obtaining copper sulphate from copper sulphate solution..
CURRENT The rate at which electricity moves along a conductor. Measured in amperes (amps) using an instrument called an ammeter.
CYTOPLASM The living contents of a cell (excluding the nucleus). Found in ALL cells.
DAY The time it takes a planet to revolve once on it axis. One Earth day = 24 hours
DECOMPOSE When a compound is split apart into two (or more) simpler substances, usually by heating.
eg if blue (hydrated) copper sulphate is heated it will decompose into anhydrous copper sulphate (a white powder) and water.
DECOMPOSE Another name for ‘rot’. A dead animal or plant will slowly decompose (rot away) if left in the ground.. It is the bacteria and fungi in the soil that make an animal decompose.
DECOMPOSER An animal that lives on the rotting remains of other organisms. Decomposers help in the recycling of dead material returning essential nutrients to the ground. eg fungi, bacteria, various beetles, worms.
DENSITY Mass per unit volume.
This means the mass (in grams) of one cubic centimetre of a substance.
The unit of density is GRAMS PER CUBIC CENTIMETRE (g/cm3).
Density is calculated as DENSITY = MASS / VOLUME
eg a block of iron with a volume of 3cm3 has a mass of 27g . This tells us the density of iron = 27÷ 3, = 9g/cm3.
This means that the mass of one cubic centimetre of iron is 9 grams.
The density of water is 1 g/cm3. Anything with a density more than that of water will sink and anything with a density less than water will float.
A substance with a LOW density will take up more space (volume) than a substance with a high density.
DIAPHRAGM A sheet of muscle across the body, above the abdomen but below the lungs, that enables us to breath.
DIFFUSION The gradual mixing of two substances. It happens because the particles in the substance are costantly moving.
DIGESTION Digestion is what happens to your food after you eat it. The food is broken down by enzymes into simple chemicals that are then absorbed into the body. Digestion takes place mostly in the intestine. (Although digestion actually starts in the mouth)
DIODE An electrical component that only allows a current to flow in one direction.
DISEASE A disease is an illness caused by a fungus, bacterium or virus.
Examples : Sore throat or upset tummy are often caused by bacteria.
Flu and measles are caused by a virus.
A lot of plant diseases are caused by fungi.
We can help stop the spread of disease by doing the following…
by washing our hands after going to the toilet or before preparing food.
by storing food at the right temperature (below 5°C) and cooking it properly.
by not sharing cups.
by using a handkerchief (or hand) over your mouth when you cough or sneeze.
DISTILLATION The name of the process used for obtaining the SOLVENT from a SOLUTION
eg obtaining pure water from sea water.
Fractional distillation is the process for separating two (or more) liquids from each other. It relies on the liquids having different boiling points. eg i. obtaining alcohol from beer ii. obtaining petrol from crude oil. The gases in air can be separated by the fractional distillation of liquid air.
DISTILLATE The liquid that has been distilled.
ECLIPSE Eclipse of the moon: when the Earth’s shadow falls onto the moon, so that the moon cannot be seen. Eclipse of the sun: When the Earth blocks out some of the Sun’s light so that it cannot all be seen.
ECOLOGY The study of animals and plants in their natural environment.
ECOSYSTEM A community of animals and plants and the habitat where they live.
EGG DUCT See FALLOPIAN TUBE.
ELEMENT The elements are the simplest of all chemicals. They are the building blocks from which every other substance is made.
There are just over 100 elements.
Examples of some chemical elements with their symbol:
Metals: Copper Cu, calcium Ca, Iron Fe, Sodium Na, Magnesium Mg
Non-metals: Oxygen O, Nitrogen N, Carbon C, Helium He, Hydrogen H, Sulphur S, Chlorine Cl
Elements consist of only a single kind of atom and cannot be decomposed.
The elements are grouped together in the Periodic table
EMBRYO The young child inside the uterus. While the child is only partly formed it is often called a FETUS.
ENDOSKELETON An internal hard skeleton (as found in humans and other vertebrates).
ENERGY Something has energy if it can be used to do any useful job of work. The unit of energy is the joule. Different types of energy include:
Nuclear energy, electrical energy, heat energy, sound energy, light energy, kinetic (speed) energy, potential (height) energy, chemical energy and strain energy.
Example of objects which contain energy:
Coal has chemical energy
A spinning flywheel has kinetic energy
A stretched elastic band has strain energy
A brick on a shelf has potential energy
Law of conservation of energy: Energy can never be created or destroyed, only changed from one form to another
Examples of energy conversion: A falling ball converts potential energy to kinetic energy.
A petrol engine converts chemical energy to kinetic, sound and heat energy.
Whenever anything slows down then kinetic energy is converted into heat energy.
RENEWABLE energy is energy that can be replaced and usually starts from the SUN eg wind power, solar energy, hydroelectric energy, wave power. Renewable energy is usually cleaner and causes less pollution. NON-RENEWABLE energy cannot be replaced eg coal, oil and natural gas (these are also called FOSSIL FUELS.
ENVIRONMENT The conditions which effect the life and development of animals and plants within the habitat. Examples of physical factors which effect the environment are air temperature, soil pH, and air humidity.
ENZYME An enzyme is a chemical that breaks down food in the gut into simple soluble substances that can be absorbed into the blood stream in the small intestine.
An example of one enzyme is Amylase which turns starch into a simple sugar.
EVAPORATION The process for obtaining the solute from a solution by warming the solution and letting the solvent evaporate completely away. eg obtaining SALT from SALTY WATER.
EXERCISE Exercise is very important to help keep you healthy:
It strengthens muscles, helps keeps your heart healthy, improves your stamina and makes you feel better.
Your heart beats faster when you exercise to get more food and oxygen to the muscles.
EXOSKELETON An exoskeleton is the hard outside skin found on some animals.
Animals that have an exoskeleton include crab, lobster, and all insects.
EYE Used for seeing. Contains a LENS which focuses light onto light sensitive cells found in the RETINA.
FALLOPIAN TUBE Sometimes called an EGG DUCT. Carries the eggs from the ovary to the uterus. Where an egg is fertilized. The eggs take about seven days to travel down the Fallopian tube.
FERMENTATION The process where YEAST converts sugar into ALCOHOL and CARBON DIOXIDE. It is a process used in the brewing industry (where the sugars in wine or beer is changes to alcohol) and in baking where the carbon dioxide makes the bread rise.
FERTILIZATION (Human) The fusion (joining) of the male and female gamete. In animals fertilization is the joining of the egg and sperm (to form a zygote).
FERTILIZATION (Plants) Fertilization happens after pollination. It is when the nucleus in the pollen joins up with the nucleus in the ovule. After fertilization the ovule swells and becomes the seed and the ovary becomes the fruit.
FILAMENT Male part of a flower. Supports the ANTHER
FILAMENT The thin metal coil if wire in a light bulb that gets hot when a current flows through it and glows. It is usually made of tungsten which has a very high melting point.
FILTER A piece of transparent, coloured plastic that absorbs some colours and not others.
FILTER The process of separating a solid from a liquid by passing it through a piece of filter paper.
Example. If you filter muddy water the clear liquid you collect is called the filtrate.
FILTRATE The clear liquid that drips through the filter paper when filtering.
FILTRATION The process used for separating a SOLID from a LIQUID eg obtaining SAND from SALTY WATER.
FISH One of the VERTEBRATES. A animal that lays soft jelly covered eggs in water. Have scaly skin. eg trout.
FLATWORMS Segmented worms, mostly parasitic eg tapeworm.
FLOWER The part of a plant that contains the reproductive organs. Where the plant makes seeds. Flowers that are insect pollinated (eg rose) have colourful or scented petals to attract insects. Wind pollinated plants (eg grass) do not have petals but still have flowers.
Plants that produce SEEDS. Eg grass, apple, oak, rose.
Non-flowering plants like ferns or moss make spores instead of seeds
FOOD CHAIN A list of organisms to show a simple feeding pattern within a habitat
eg CABBAGE LEAF → SLUG → THRUSH → FOX
A food chain always starts with a plant:
PLANT → HERBIVORE → CARNIVORE
The arrows show the transfer of food energy from one organism to the next.
FOOD WEB A diagram that represents several interlinked food chains
FORCE A Push or a pull. Measured in NEWTONS (n). A force can cause an object to SPEED UP, SLOW DOWN OR CHANGE SHAPE. Examples of forces: friction, gravity, magnetism, electrostatic charge. Forces usually work in pairs.
An object will speed up or slow down if the forces on it are not balanced.
If an object is stationary (or moving at a steady speed) then the forces on it must cancel themselves out (we say that the forces are in equilibrium).
A force can cause an object to SPEED UP, SLOW DOWN OR CHANGE SHAPE
Examples of forces:
Friction (a force caused by things rubbing together. Friction makes things slow down)
Air resistance (when something moves through the air, air resistance slows it down. A streamlined shape would reduce the air resistance so would go faster)
Gravity (pulls objects down towards the centre of the Earth. Gravity causes things to have weight)
Magnetism (A magnet can attract iron or another magnet. Two similar poles will repel)
Upthrust (Upthrust is the force that makes things float or feel lighter in water)
An object will speed up or slow down if the forces on it are not balanced.
If the forces on an object are the same it will not move (or stay moving at a steady speed)
FOSSIL FUEL Fossil fuels are fuels made from the remains of dead animals or plants
The main fossil fuels are coal, oil and natural gas. Fossil fuels are fairly cheap and easy to obtain but they are slowly running out (and cannot be replaced). They also cause lots of pollution.
FREQUENCY The rate at which something occurs.
In SOUND it means the number of sound vibrations that occur every second. Measured in hertz (Hz). A higher frequency means a higher pitch.
FRICTION A force which causes a moving object to slow down. Friction always acts in the OPPOSITE direction to the direction of motion. Sometimes friction is an ADVANTAGE eg slowing down a man with a parachute or the brakes of a car slowing it down; and sometimes it is a disadvantage eg air resistance slowing down a car and using more petrol, or bearings heating up.
Friction happens when two surfaces rub together
Rough surfaces have a lot of friction. Smooth surfaces have only a little friction.
Friction is a force which tries to slow things down. Friction causes heat.
Without friction our shoes would have no grip on the floor and cars would not be able to slow down or turn corners. (see Force)
Air resistance (or drag) is a kind of friction caused by air slowing down moving objects (like a parachute or a car)
Friction can be reduced by using rollers or a lubricant like oil between the surfaces that touch. (See Air Resistance)
Friction makes things get hot (converts KINETIC ENERGY into HEAT ENERGY).
FRUIT A fruit is the ovary of a plant and is where the seeds are formed.
It is a female part of the plant.
Examples of fruit: banana, apple, orange, tomato, cucumber
FUEL A fuel is something we can burn to obtain heat energy (like coal, oil or wood)
Fuels contain chemical energy.
FUNGI A group of plants that do not possess green chlorophyll so cannot carry out photosynthesis.
They take their food from the material they are growing on/in. They reproduce by forming spores.
Examples of different fungi: mushroom, yeast, mould.
Fungi (along with bacteria) are very important in the food chain for the recycling of nutrients in the soil.
Some fungi are harmful and can cause disease in crops (eg potato blight).
Some fungi are useful to man eg yeast which is used to ferment sugar and produce alcohol in the brewing industry.
FUSE A fuse is a short length of wire designed to melt (or ‘blow’) when the current flowing though it gets too high. It is a used as a safety device to cut off the supply of electricity when something goes wrong. All 13A plugs contain a fuse. (See Appendix 3 for the symbol).
GALAXY A large number of stars grouped together. Our sun is in a galaxy called the Milky Way. The universe contains many galaxies.
GAMETE One of the cells that join (fuse) during sexual reproduction.
It is from the gametes that the young animal or plant inherits characteristics from its parents.
MALE GAMETE: in plants = pollen, in animals = sperm
FEMALE GAMETE: in plants = ovule, in animals = ovum
GAS One of the three states of matter. (the other two are solids and liquids).
A gas always completely fills its container and has no fixed shape
A gas can be compressed (squashed into a smaller space).
If a gas is cooled down it will condense and form a liquid.
The particles in a gas are far apart and move rapidly in all directions
GERMINATION Germination is when seeds start to grow.
Seeds need three conditions to germinate:
1. Warmth, 2. Air (Oxygen) and 3. Water
GERMINATION PERIOD The time between planting a seed and the first growth of the new plant
GESTATION PERIOD The time taken for a baby to grow inside its mother.
The gestation period for a human is 9 months (about 38 weeks)
GILLS Gills are used by a fish to take oxygen from the water.
GRAPHITE A form of carbon. Graphite is the black substance inside pencils (the pencil lead).
Lead used to be used in pencils but is not used any more due to it being poisonous.
GREENHOUSE EFFECT Certain gases in the air like carbon dioxide and methane trap heat from the sun and cause the air to heat up (in the same way as the inside of a car or greenhouse heat up on a sunny day). The greenhouse effect is responsible for global warming.
GRAVITY Gravity is the force that pulls all objects down towards the centre of the Earth.
Gravity causes objects to have weight.
All the objects in the solar system have gravity. The bigger the planet, the more gravity it has and so the more things will weigh.
GUT See ALIMENTARY CANAL
HABITAT The place where an animal or plant makes its home
eg woodland, fresh-water stream, puddle.
HEART The heart is an organ to pump blood to and from the lungs and around the body. The heart is made mostly of muscle and contains valves to control the direction of blood flow.
To keep the heart healthy we should eat a diet low in fat and salt, eat lots of fruit and vegetables and take regular exercise. Smoking and drinking alcohol can also damage the heart. (See Keeping Healthy)
HEART RATE The speed at which our heart pumps. The normal heart rate of a child is 80 b.p.m (beats per minute) and an adults average heart rate is 72 b.p.m..
Our heart rate will go up when we take exercise because our muscles need more food and oxygen so the heart has to pump faster. (see Pulse)
HERBIVORE (Herbivorous) An animal that eats only plants. (leaves, seeds, berries, bark etc) eg snail, mouse
HORMONE Chemicals in the body that control certain functions such as the rate of a boy/girls growth. Hormones are made in several parts of the body. The hormones responsible for the changes at puberty are made in the testes or ovaries.
HOST The organism on which a parasite is living
eg if a flea lives on a fox then the fox is the host and the flea the parasite.
HYDROCARBON A compound containing only the elements HYDROGEN and CARBON. eg petrol, wax. Because it is a compound it will burn more than one product.
Hydrocarbons will burn to form the compounds carbon dioxide and water.
IMPERMEABLE Impermeable means waterproof. An impermeable rock (like granite) will not let water seep through it. (The opposite of impermeable is permeable)
INSECTS Animals that have 3 pairs of legs, 3 parts to the body and usually 2 pairs of wings eg butterfly, ant. The eggs from an insect hatch into larvae. The larva is the young form of an insect. A caterpillar is the larva of a butterfly. A maggot is the larva of a fly.
Useful insects include the bee which helps pollinate flowers and also provides us with honey. A lot of insects are decomposers (eg fly and many beetles) and play an important part in the ecosystem recycling dead plants and animals.
Insects can carry disease (eg mosquito carries malaria). Insects can harm food crops which either get eaten or damaged by insects.
INSOLUBLE Cannot be dissolved. eg sand is insoluble in water; sugar is insoluble in petrol NOTE: when using the words soluble or insoluble then you should give the name of the solvent being used.
INSULATOR Electrical insulator: A material that does not allow electricity to flow through it (like plastic or glass).
Thermal insulator: A material does not allow heat to pass through it easily (like wool or plastic)
A good insulator will be a poor conductor
A base of saucepan is made of metal because metals are good conductors of heat,
The handle is often made of wood because wood is a good insulator
A change in a substance that is permanent.
Examples of irreversible changes are BURNING toast, COOKING a cake or an egg, RUSTING.
INVERTEBRATES Animals without a backbone. All animals except for mammals, birds, reptiles, amphibians and fish are invertebrates.
i. Take regular exercise. This improves stamina and keeps the heart healthy
ii. Eat a diet low in fat and salt (fat can damage the heart). (see Balanced Diet)
iii. Eat lots of fruit and vegetables (which contain important vitamins and minerals)
iii. Avoid a lot of alcohol (alcohol can damage the heart and liver)
iii. Do not smoke (smoking can damage the lungs)
iv Do not take drugs (drugs can damage the liver)
KIDNEY i) Removes waste (urea) from the blood. ii) Removes water from the blood and so controls the blood concentration. The liquid which the kidneys remove is called URINE which passes down the URETER to the bladder.
The last stage in the GUT. An organ in our body where water absorption takes place.
LEAVES Where photosynthesis is carried out in a plant. Have a large surface area to absorb the sunlight.
LED Light Emitting Diode. A small device that gives out light but only uses a tiny current. It allows a current to only flow in one direction.
LEVER A device for increasing the effect of a force. The load needs to placed near to the fulcrum and the effort (or applied force) further from the fulcrum.
LEVER LAW Sometimes called the law of MOMENTS. When a lever is balanced then this law applies:
Force on the left x its distance from the fulcrum = force on right x its distance from the fulcrum
ie on left…. 4n x 9cm = 36 on the right… 6n x 6cm = 36
A special glass tube used to cool down and condense a hot gas. Water flows through an outer glass jacket and this keeps the inner glass tube cool.
LIFE CYCLE The main stages in the life of an animal or plant.
The human life cycle is:
unborn baby — Baby — Child — (Puberty) Adolescence — Adult — Old age
The life cycle of a flowering plant is:
Pollination –Fertilization Seed dispersal — Germination — Growth of plant
LIFE PROCESSES There are seven processes that are carried out by all living organisms
Movement, Growth, Reproduction, Nutrition (feeding), Respiration, Excretion (getting rid of waste) and Respond to a stimulus (see Living Things)
LIGAMENT Ligaments hold the bones together at each joint in your body.
LIGHT RAY A light ray is shows the path of light in a diagram. A light ray should be drawn as a single straight line with one arrow on it.
LIQUID In liquids the particles are still close together but only held together by WEAK electrical forces which leaves them free to slide over one another. A liquid has a fixed volume but takes up the shape of its container.
LIME Sometimes called quicklime. Made of a compound called calcium oxide. (See calcium oxide). It is alkaline oxide and is used in agriculture to neutralise an acid soil.
LIVER The largest organ in the body. It helps keep a balance of nutrients in the body and can also help remove poisons from the body. This is why the liver is often damaged when a person drinks too much alcohol (a poison) or takes drugs.
LUMINOUS A luminous object is one that gives out light eg the sun, the stars, a light bulb or candle.
(Remember, the Moon is NOT luminous and gives out no light of its own. We see the Moon due to light from the Sun being reflected from the Moon back to the Earth)
LUNGS Organ in the body that is responsible for gaseous exchange ie
i) Transfers oxygen to the blood.
ii) Removes carbon dioxide from the blood.
MALLEABLE Malleable means can be hammered into thin sheets. Most metals like gold, copper or lead are malleable.
MAGNET A magnet is a material that produces a magnetic force.
All magnets have two poles..
The pole is the part of a magnet where the magnetism is strongest.
The only common material that magnets attract (stick to) is iron.
All magnets have two poles (North seeking pole and South seeking pole)
Similar (like) poles repel (push apart) and different (unlike) poles attract each other. Magnets are used to make electric motors and also to separate iron from other materials.
.Lines of magnetic force that run from the orth magnetic pole of a magnet to the south magnetic pole
MAMMALS One of the VERTEBRATES. The young are born alive. The females have mammary glands and suckle their young from nipples on mammary glands. Have hair or fur on their bodies eg mouse, man. Warm blooded.
MASS The mass of an object is a property of the object which NEVER changes. It is a measure of an objects resistance to a change in motion. Mass is measured in kilograms (or grams)
MENISCUS The curved surface found on the surface of a liquid. NOTE: Any readings taken of the volume of water in a container should be taken to the LOWER side of the meniscus.
METAL An element that has most of the following properties: Malleable, ductile, shiny, good conductor of heat and electricity. Metal oxides, if they dissolve, form ALKALINE solutions. Eg copper, iron, tin, gold.
MICRO-ORGANISM A micro-organism is a living thing that is so small you need a microscope to see it. Micro-organisms are either fungi, bacteria or viruses .
Helpful micro-organisms: yeast is a fungus that is used for making bread or beer
Bacteria that live in the soil are helpful as they cause things to rot and provide food for plants
Bacteria are also used to term milk into yogurt or cheese.
Bacteria, viruses and fungi can all cause disease
Bacteria can cause a tummy upset or sore throat, viruses cause flu or measles
Bacteria can also cause food poisoning. (See Disease)
MINERAL A naturally occurring substance from the ground, usually crystalline. eg Malachite
MITOCHONDRION Mitachondria are where respiration is carried out in all cells. They provide the cell with energy. (see cell)
MIXTURE At least two substances present that can be separated without a chemical reaction taking place. No new substance is formed when a mixture is separated.
Examples of mixtures: AIR, SEA WATER, INK.
The substances in a mixture can be present in any proportion.
MOLECULE The particle formed when two or more atoms chemically join together.
MOLLUSCS Animals that have muscular foot and soft body eg slug, snail, oyster.
MOON The Moon is a natural satellite of the Earth. (A satellite is an object that revolves around a planet). The Moon orbits the Earth once every 28 days. The moon does not give out light of its own. We see the moon due to light from the Sun being reflected back to the Earth.
MOSS A small plant. It has no proper roots. It reproduces spores. Live in damp, shady places.
MUSCLE Muscles hold the bones in place and help us move. Muscles usually work in pairs.
When one muscle contracts (or gets shorter and pulls) the other muscle relaxes.
NON-METAL An element that has most of the following properties:
Brittle, poor conductor of heat and electricity. Non-metal oxides, if they dissolve, form ACIDIC solutions. Note: CARBON, even though it conducts electricity, forms an ACIDIC oxide and is therefore classed as a non-metal.
NUCLEUS Controls the function and behaviour of the cell. Found in ALL living cells. Contains the GENETIC MATERIAL.
NUTRIENT A substance found in food that is needed to help us grow and stay healthy.
Types of nutrient:
Carbohydrates (starch and sugar, found in bread, pasta and sweets) give us energy
Proteins (found in meat, fish and cheese) are needed for growth and repair of cells.
Vitamins and minerals (found in fresh fruit and vegetables) keep us healthy.
OMNIVORE An animal that eats plants and meat. (Omnivorous)
eg rat, human
OPAQUE A material is opaque if it does not allow light to pass through it.
Brick and wood are opaque. (see Transparent and Translucent).
Opaque objects form the best shadow by blocking light.
ORE A mineral from the ground from which a metal can be obtained.
ORGAN An organ is a part of our body with a particular job to do. Examples:
Heart: pumps blood Lungs: add oxygen to the blood and removes carbon dioxide
Ears: hearing and balance Brain: Co-ordinates and controls our body
Skin: keeps out germs Kidney: removes poisonous waste from the blood
Eyes: Seeing Stomach and Intestine: digests food
ORGANISM The name we give to any animal or plant.
Examples of different organisms: dog, amoeba, flea, bacteria, daisy.
OVARY The part of a flower where the seeds are formed,. Contains the OVULES. After fertilization the ovary will often form a FRUIT.
OVARY Where eggs/ova (female gamete) are manufactured.
OVULES The part of a flower that contains the FEMALE GAMETE. The ovules will swell and become seeds after fertilization.
OVUM Another name for the egg cell found in an animal. The ovum contains the female gamete (see Gamete). It is from genes in the ovum (egg) that we inherit characteristics from our mother.
PARALLEL CIRCUIT In a parallel circuit the current divides and follows more than one path.
PARASITE An animal or plant that lives on (or inside) the body of another living organism eg leech, flea, tapeworm
PENIS An organ found on male mammals. Contains a tube called the urethra. Where urine and sperm leave the body.
PERMEABLE A rock that allows water to soak into it is called permeable. Chalk and limestone are permeable rocks. A permeable rock is porous (full of tiny holes).
The opposite of permeable is impermeable. Granite is an impermeable rock.
PETALS Part of a flower that attracts the insects using scent and colour. This is to help POLLINATION take place.
pH SCALE A scale of numbers (from 1 to 14)which shows how acidic or alkaline a liquid is. pH 7 is neutral. Less than pH 7 is acid. More than pH 7 is alkali. The nearer to pH 7 a solution is the weaker it becomes (ie pH6.5 is a very weak acid)
The process by which plants manufacture sugar using carbon dioxide from the air and water from the soil.
Energy for the process comes from sunlight, absorbed with the help of chlorophyll. Oxygen is released as a waste product. Takes place in the chloroplasts.
NOTE: photosynthesis takes place only during the day (or when there is light).
CARBON DIOXIDE + WATER → SUGAR + OXYGEN
(reactants) → (products)
PHYLUM One of the divisions used in the classification of animals. EG Phylum Chordata are the VERTEBRATES
PITCH How high or low a sound is. The pitch of a vibrating object can be increased by:
i) making it shorted ii) Making it weigh less.
In the case of a vibrating string making it tighter.
PLACENTA An organ that supplies the developing embryo with food and oxygen from the mother’s blood. Waste (carbon dioxide and urea) travels back through the placenta from the embryo to the mother. Other substances (alcohol, nicotine, drugs) can also travel through the placenta and these can effect the development of the embryo. Blood cells do NOT pass through the placenta.
PLANET A non-luminous body in orbit around the Sun. It is held in orbit around the sun by the pull of the sun’s gravity.
PLANT A flowering plant has four main parts:
Leaves (where photosynthesis takes place): (Nutrition)
Stem (to transport food and water around the plant
Roots (to support the plant)
Flower (where seeds are made) (Reproduction)
POLLINATION When pollen reaches the stigma during reproduction in a flowering plant. There are two main methods of pollination: Insect pollination (eg as in rose, apple); wind pollination (eg as in grass).
Cross-pollination is when one plant pollinates another (as in the examples above)
Self-pollination is when a plant pollinates itself.
POOTER Used in ecology to sample small invertebrate. It consists of a small glass bottle containing two tubes. You suck on one tube and the animal gates drawn down the other into the bottle.
POPULATION A group of animals or plants of the same species living in a particular area.
POWER The rate at which energy is converted from one form to another. The rate at which work is done.
[ie the number of joules per second
In electricity the rate at which electricity is used. Power = volts x amps
Units of power = WATTS]
PRECIPITATE The insoluble solid formed when either two liquids react together or a gas reacts with a liquid. eg Carbon dioxide reacts with limewater to form a white precipitate of calcium carbonate.
PREDATOR An animal that hunts for food. eg hawk, pike.
The food it hunts for is known as its prey. (See Prey)
PREY An animal that is eaten by another animal is known as its prey.
Look at the following food chain: Lettuce Slug Thrush Fox
The slug is the prey of the thrush.
The thrush is a predator (of the slug) and the prey of the fox.
The fox is the predator of the thrush
PRESSURE Force per unit area. This means the force (in Newtons) on one square metre (or square centimetre) of area.
Pressure is calculated as PRESSURE = FORCE / AREA
The unit of pressure is NEWTONS PER SQUARE CENTIMETRE (N/cm2).
If a force presses against a small area then the pressure will be high.
If the same force pushes on a large area the pressure will be less.
eg Why does it help to wear large boots walking in snow?
Answer: because with large boot your weight is spread out more making the pressure on the snow LESS.
eg Why are football studs used? answer because football studs have a small area. This increases the pressure on the ground so they sink in and help stop the player slipping.
PRODUCER The first organism in a food chain. Always a green plant. Green plants are the only organisms that can carry out photosynthesis and produce their own food from simple chemicals in the soil and air. Note: fungi do not possess chlorophyll and so are NOT considered as producers
PROTEIN Proteins are an important part of our diet as they are needed for normal growth.
Foods rich in protein include meat, fish cheese and milk.
PROSTATE GLAND Gland in the male that produces a liquid to help nourish the sperm.
PROTOZOA Single celled animals eg amoeba
PUBERTY The time in a child’s life when his/her sex organs start to develop. The changes are brought on by HORMONES in the body. Puberty normally happens when a boy is between 11 years old and 14 years old and slightly earlier in girls.
After puberty a boy can produce sperm and a girl will produce eggs.
PULSE The pulse is how we can measure our heart rate. Each pulse is one beat of the heart. At certain points in our body we can feel the increase in blood pressure every time our heart beats.
We can normally feel the pulse at our wrist and at the side of the neck.
The normal pulse for a child is 80 beats per minute. Our pulse will increase when we take exercise.
PURE Only a single substance present. Not able to be separated into any other substance without a chemical reaction taking place.
QUADRAT A square frame of wood (or area of land), often 1mx1m, used during ecology to estimate populations.
REACTION A chemical reaction ( or chemical change) takes place whenever a new substance is formed. The signs of a chemical change are:
i) a change in temperature (eg getting warm) ii) a change in colour.
REDUCE (Reduction) To remove the oxygen from a compound eg Zinc will REDUCE copper oxide to form copper and zinc oxide. Reduction is an important way of obtaining metals from their ores eg In the steel industry the carbon in COKE is used to take the oxygen away from the iron ore (containing iron oxide) to leave molten iron.
REDUCING AGENT An element good at removing oxygen from a compound (see Reducing)
eg carbon is used as a reducing agent when it removes oxygen from iron oxide.
RELAY A relay is a kind of switch that contains an electromagnet made from a coil of wire. It has four connections, two for the coil and two for the switch. The coil can be operated by a very small current, but the relay contacts can switch a much larger current.
REFLECTION When light bounces off a smooth surface (eg a mirror) and forms an image behind it.
REFRACTION When light gets bent by passing from air into water or glass (or passing back again).
REPTILES One of the VERTEBRATES. An animal that lays soft shelled eggs on land. Bodies covered in hard scales. eg snake, lizard
RESIDUE The solid remaining in the filter paper after filtering
(or any other small amounts of solid left after an experiment).
RESISTANCE The property of a conductor that reduces the current flowing through it.
[Resistance is measured in OHMS, and can be calculated using the formula V=IR where V=voltage, I=current and R=resistance]
RESISTOR An electrical component that reduces the amount of current flowing in a circuit.
RESPIRATION A process by which all living organisms release energy from sugar. Oxygen is needed for the process.
Carbon dioxide and water are released as waste products.
Word equation: SUGAR + OXYGEN —-> CARBON DIOXIDE + WATER
NOTE: Even though respiration takes place all the time (in animals and plants) but during the day in plants photosynthesis is a more rapid process.
Respiration provides energy for vital processes such as growth, cell repair, reproduction, chemical reactions in the cell, movement and warmth.
ROOT Part of a plant that absorbs water and dissolved mineral salts from the ground.
The root also supports the plant in the soil.
A root will often have root hairs to increase its surface area.
ROUNDWORMS Tiny non-segmented worms. Mostly parasitic eg ring-worm.
SAPROPHYTE A decay organism. Saprophytes cause the remains of organisms to rot. They are vital for the recycling of nutrients into the ground. eg fungi and bacteria.
SATELLITE An object in orbit around a planet. eg the moon is a natural satellite of the Earth. There are also many artificial satellites around the Earth eg Meteostat is a weather satellite.
A solution that cannot dissolve any more solid unless the temperature is changed.
NOTE: if the temperature increases the solution will not be saturated any more as it will be able to dissolve more solid.
SOLUBLE Can be dissolved. eg Salt is soluble in water; iodine is soluble in alcohol
SCAVENGER An animal that lives from the remains of other animals. eg shrimp, vulture.
SEPALS Part of a flower. Small green leaves to protect the bud.
SERIES CIRCUIT In a series circuit the current follows a single path and does not divide.
The current will be the same in every part of a series circuit
A suspension of an insoluble solid (like chalk) can be separated from water by filtering.
Something dissolved in water (like salt) can be separated from water by evaporating away the water.
Filtration separates a solid from a suspension eg chalk from chalk and water
Evaporation separates the solute from a solution eg water from salty water
Distillation separates the solvent from a solution eg obtaining water from salty water
A separating funnel separates two immiscible liquids eg petrol from water
Iron can be separated from other materials by using a magnet
Separating mixtures involves no chemical change ie no new substance is made.
Reproduction that requires fertilization. eg production of seeds in plants (grass, daffodil). Most animals (including humans) reproduce by sexually.
All multi-cellular animals can reproduce sexually.
Disadvantage: often a slow process
Advantage: offspring are different to parents. This allows natural selection and accounts for the evolution of different species.
SHORT CIRCUIT When a piece of wire allows electricity to take a ‘short cut’. A short circuit of a battery (when a wire connects the positive to the negative terminal on a battery ) can be very dangerous. The wire may get hot and the battery and will always run down very quickly. A bulb that has been short circuited will not light up
SKELETON Made up of rigid BONES. Provides a framework to support the other organs. Muscles and tendons are attached to the bones to hold the skeleton in shape.
SKIN Protects the body from germs. Blood capillaries in the skin open and close to help regulate our body temperature. Stops us drying out
Organ where most of the digestion/absorption of food takes place. The small intestine is lined with tiny villi which increase its surface area.
SOLID In a solid the particles are held rigidly together by STRONG electrical forces and can only just vibrate. A solid has a fixed volume and fixed shape.
SOLUTE The SOLID that has been dissolved to make a solution. eg When salt is dissolved in water then the salt is the solute.
The solute is separated from a solution by EVAPORATION.
SOLUTION The liquid obtained by dissolving one substance in another.
SOLUTE + SOLVENT = SOLUTION eg SALT + WATER = SALT SOLUTION
SOLVENT The LIQUID used to make a solution.
eg When salt is dissolved in water then the water is the solvent.
Examples of good solvents include WATER, PETROL, ALCOHOL
The solvent is removed from a solution by DISTILLATION.
SOUND To produce a sound something must be vibrating.
We hear the sound when vibrations in the air reaching our ears.
Sound travels quicker in solids and liquids than it does in air.
Sound cannot travel through a vacuum.
The pitch of a sound is how high or low it is. (See Pitch)
If the frequency of the vibrations increases the pitch will be higher
(frequency = the number of vibrations per second)
The volume of a sound is how loud it is. (See Volume)
The amplitude of a wave is its size: larger amplitude = louder volume
SPEED How far something moves in one second (or 1 hour).
Normal metric unit = Metres per second (m/s). Speed = distance ÷ time
Example a ball takes 2 seconds to roll 5 metres. What is the average speed of the ball
Speed = 5 ÷ 2 speed = 2.5 m/s (this is the average speed because the ball may not have been going the same speed for the whole distance).
SPERM The sperm carries the male gamete in an animal. It has a tail and can swim around.
The sperm is much smaller than the egg (ovum). (see Gamete).
It is from genes in the sperm that we inherit characteristics from our father.
SPERM DUCT A tube that carries sperm from the testis to the urethra.
STAMEN The male part of a flower. Where the pollen is made. Is made up from a FILAMENT and ANTHER.
STAR A star is at the centre of any solar system
Stars are very hot and give out large quantities of heat, light and other radiation.
Our Sun is a typical (although quit small) star.
STATES OF MATTER The three states of matter are SOLID, LIQUID and GAS.
STEM Transports food and water around a plant. Holds apart the leaves and flowers.
STIGMA Part of a flower where pollen lands during pollination.
STOMACH Part of the alimentary canal where food is held before it is passed into the small intestine. Some digestion takes place in the stomach.
STYLE The part of a FLOWER that connects the stigma to the ovary.
The force on the surface of a liquid that causes the liquid to behave as if it were covered by a thin skin. Surface tension can support light objects such as an insect on the surface of water.
It is destroyed by liquids such as soap and detergent.
SUSPENSION A mixture containing tiny particles of solid mixed with water.
Eg a suspension of chalk in water.
The solid in a suspension can be separated by FILTRATION.
SWITCH A switch is used to start or stop electricity flowing in a circuit.
When a switch is OPEN the electricity cannot flow (a bulb would be OFF)
When the switch is CLOSED the electricity can flow (and a bulb would be ON)
SPST (Single Pole Single Throw): This is an ordinary on/off switch.
SPDT (Single Pole Double Throw): Works like railway-line points. Can connect electricity to one wire or another.
Push switch, similar to a normal bell switch, only on while it is pressed.
Reed switch, operated by a magnet.
SYNTHETIC Synthetic means ‘man-made’. A synthetic substance is not natural. Examples of synthetic (man-made) materials are plastic, brick and glass
TEMPORARY CHANGE A change that is not permanent like evaporation, melting, solidifying, condensation or dissolving.
TEMPERATURE A measure of how hot or cold something is.
Temperature is normally measured using a thermometer in degrees Celcius (°C)
Some useful temperatures to know:
Boiling point of water = 100°C
Melting point of water = 0°C (This is the temperature of melting ice)
Human body temperature = 37°C
THERMOMETER An instrument used to measure temperature.
THORAX The part of an animal between the head and the abdomen. In a human the thorax contains the heart and lungs. In an insect the thorax is where the wings and legs are attached.
TESTIS Where sperms (male gamete) are manufactured in a human.
TOP CARNIVORE The carnivore at the end of a food chain. eg fox, pike.
TRACHEA Another name for the windpipe
TRANSMISSION When light passes straight through something like a piece of transparent paper.
TRANSLUCENT Something is translucent if some light can pass through it but no detail can be seen (like a sheet of paper). A translucent object will still make a shadow because it blocks some of the light.
TRANSPARENT Something is transparent if light can shine through it (like a sheet of glass)
A transparent object will usually not form a shadow.
TRANSPIRATION Transpiration is the name of what is happening when a plant loses water. Water enters the plant through the roots, travels up the stem and leaves the plant through its leaves
Used in ecology to sample small invertebrates in litter. How it works: Some litter is placed in a funnel with a lamp over the top. The animals move away from the light and heat and eventually fall through the base of the funnel.
UNIVERSE The name given to the collection of everything that exists in space.
URETER The tube that carries urine from the kidney to the bladder
URETHRA The tube that carries urine from the bladder to outside the body.
UTERUS Organ where the embryo/foetus develops.
VACUOLE A large vacuole is found only in plant cells. It contains cell sap and helps keep the cell rigid.
VARIATION Variation is the word which describes differences between one animal (or plant) and another of the same species. These characteristics might be inherited from the parents (or genetic) or they may be environmental.
Eg The colour of your eyes was information inherited from your parents (genetic)
The height of a plant could be due to the available light (environmental)
VEINS Blood vessels that carry blood towards the heart. (see ARTERIES)
VERTEBRATES Animals with an internal hard skeleton. The vertebrates include mammals, birds, reptiles, amphibians and fish.
VIRUS A virus is a tiny micro-organism that lives inside the cell of another animal or plant. A lot of viruses can cause diseases like flu or measles (See Micro-organism)
VITAMIN vitamins are substances in food that we need a small amount of to keep us in good health. Examples:
Vitamin C is found in lemons and oranges and green vegetables.
Lack of vitamin can cause unhealthy gums and an illness called scurvy
VOLTAGE The push, or potential difference, that tries to push an electric current around a circuit. Measured in volts using an instrument called an ammeter.
VOLTMETER An instrument used to measure potential difference (voltage). It is placed in parallel with the conductor being tested and has a high resistance.
VOLUME How loud or soft a sound is. The AMPLITUDE of a sound wave controls the volume.
VOLUME The amount of space something takes up.Volume = height x width x depth
Unit of volume:
In solids volume is measured in cubic cenimetres (cm3)
In liquid and gases volume is measured in millilitres (ml)
The volume of a liquid can be measured using a measuring cylinder
WARM-BLOODED Animals whose body temperature is constant are called warm-blooded. eg Human: body temperature 37oC.
The only warm-blooded animals are birds and mammals.
WATER Water is a colourless liquid. It is needed by all animals and plants.
Water is a compound of hydrogen and oxygen and has the formula H2O
Water boils at 100°C (called its boiling point)
Water freezes at 0°C (called its melting point)
Water is the most common liquid on Earth.
Heat from the Sun (1) causes water in the sea to evaporate and form water vapour (2). As the water vapour rises it cools down and condenses to forms clouds (3). Wind blows the clouds over land where the water falls as rain (4). The rainwater collects into rivers (5) and flows back to the sea to be reheated by the Sun and the cycle starts again.
Note: Evaporation = Liquid to gas Condensation = gas to liquid
WEIGHT The weight of an object is caused by the pull of gravity and will change if gravity changes. ie If gravity gets less then the weight will also get less. Weight is measured in newtons.
The pull of the Earth’s gravity is approx. 10N on every 1kg (ie 1N on 100g)
eg the mass of a block of butter = 500g On the Earth it’s weight will be 5 newtons. On the Moon its mass will be the SAME as on the Earth but it’s weight will be LESS.
YEAR The time it takes a planet to complete one full orbit around the sun. On Earth one year = 365.24 days.
YEAST A single celled FUNGUS used in baking to make bread rise and in brewing to make alcohol.
ZYGOTE The cell formed by the fertilization of a male and female gamete.