Year 7 Revision booklet

1. Year 7 Revision booklet • One sheet per topic • Mind map, note or questionnaire type form • Some links to the internet • For on-line Biology tests • go to http://www.docbrown.info/ks3biology/ks3biology.htm • For on-line Chemistry tests • go to http://www.docbrown.info/ks3chemistry/ks3chemistry.htm • For on-line Physics tests • go to http://www.docbrown.info/ks3physics/ks3physics.htm • For a general revision site www.scibermonkey.org • One sheet per topic • Mind map, note or questionnaire type form • Some links to the internet • For on-line Biology tests • go to http://www.docbrown.info/ks3biology/ks3biology.htm • For on-line Chemistry tests • go to http://www.docbrown.info/ks3chemistry/ks3chemistry.htm • For on-line Physics tests • go to http://www.docbrown.info/ks3physics/ks3physics.htm • For a general revision site www.scibermonkey.org Year 7 Revision booklet

2. 7A GROUPS of CELLS make TISSUES GROUPS of TISSUES make ORGANS Cells are very small Microscopes are needed to see them NUCLEUS Contain DNA and the Genes which control our inherited features The nucleus also makes PROTEINS, vital for new Cells (growth) All living things are made of CELLS the basic building blocks of life Magnification Power of eyepiece lens X Power of Objective lens Cells specialise for different functions Palisade cells perform PHOTOSYNTHESIS in the Chloroplasts which trap light energy and turn it into food, starch (carbohydrates) All Cells have NUCLEUS CYTOPLASM CELL MEMBRANE Plant cells also have VACUOLE CHOLOROPLASTS CELL WALL Year 7 Revision booklet

3. 7B Male gamete (Sperm or Pollen)+ Female Gamete (Egg) = Fertilised Cell (Zygote) Zygote becomes ball of cells, then embryo, then foetus. 9 months to birth Male puberty: Deeper voice Testes drop Face hair & spots Muscles & Shoulders develop Ovum is much, much bigger than sperm. One ovum per month. It waits for up to 4 days for a sperm before it dies. REPRODUCTION The way a species survives Female Puberty: Hips broaden Breasts develop Menstruation starts (Periods) Tut tutting, spots Key words: Uterus (womb), oviduct (fallopian tube), placenta, amniotic sac & fluid, cervix, vagina, penis Sperm are tiny, have large head (nucleus) long tail for swimming and middle bit for energy Year 7 Revision booklet

4. 7C Environment and feeding relationships Secondary Consumer: Wolf • A HABITAT is where an organism lives. • A habitat supplies plants and animals (organisms) with shelter, energy and materials • Animals and plants are ADAPTED to their habitats • Plants make their own food (by photosynthesis) • Animals eat plants (HERBIVORES or PRIMARY CONSUMERS) or other animals (PREDATORS or SECONDARY CONSUMERS) • These feeding relationships are shown in a FOOD CHAIN • An arrow  means Food for, pointing into mouth of consumer. • Many food chains for a complex number of organisms are shown in a FOOD WEB Energy Source:The Sun Primary Consumer: Deer Producer: Grass A Food Chain starts with energy from the sun being turned into food by the Producer (any plant). Primary consumers get about 1/10 of the plant’s stored energy when they eat a plant, secondary consumers get about 1/10 of the stored energy of the primary consumer when they eat it. So Food chain are always short, never more than 4 links A Food Web! Year 7 Revision booklet

5. Variation and Classification 7D VARIATIONVariations, e.g. eye and hair colour,which parents pass to offspring are called inherited variations these are caused by taking a gene from the father or mother alternately. Variations, e.g. language or scars, caused by the environment are called environmental variations CHROMOSOMES A human has 23 pairs of chromosomes. Each chromosome carries an instruction for an aspect of the new organism, e.g. its sex. Gametes (sperm and egg cells) each carry 23 unpaired chromosomes which become paired in the zygote Sperm carry and X and Y chromosome Eggs carry X and X chromosomes So an XY becomes a new boy and an XX a new girl. KingdomPhylumOrderClassOrderFamilyGenus Species Insects and Spiders are different orders because: Spiders have 8 legs & 2 part bodies Insects have 6 legs & 3 part bodies Year 7 Revision booklet

6. 7E Acids and Bases • Acid + Base= Salt + Water (e.g. Hydrochloric Acid + Sodium Hydroxide= Sodium Chloride + Water) • Acid + Metal= Salt + Hydrogen (e.g. Hydrochloric Acid + Magnesium = Magnesium Chloride + Hydrogen) • Acid + Carbonate = Salt + Water + Carbon Dioxide (e.g. Hydrochloric Acid + Copper Carbonate = Copper Chloride + Water +Carbon Dioxide) • All 3 reactions are neutralisation reactions • All acids contain Hydrogen • The pH Scale shows: • acidity or alkalinity • In farming Lime (Calcium oxide) is used to neutralise acid fields • Toothpaste is a weak alkali used to neutralise mouth acids • Indigestion tablets neutralise stomach acids (indigestion) • Tea, Citrus fruits & vinegar are all acids • Hydrogen Test is: “pop” with lighted splint • Carbon Dioxide test is: limewater (Calcium Hydroxide) goes cloudy • Acid rain is caused by Sulphur (from coal) burning to make sulphur dioxide a very acid gas Year 7 Revision booklet

7. 7F Simple Chemical Reactions • There are 6 basic chemical reactions: • COMBINATION is when two substances combine to make one new substance. • DECOMPOSTION is when one substance breaks down into two new substances • CORROSION is when iron reacts with water and oxygen to form a hydrated iron oxide (RUST) • NEUTRALISATION is the reaction between and ACID and a BASE • (ACID + BASE + SALT + WATER) • REVERSIBLE reactions are reactions which can go forwards and backwards. Reactions with Water and anhydrous Cobalt Chloride or Anhydrous Copper Sulphate are REVERSIBLE. • DISPLACEMENT (or REDOX = REDUCTION / OXIDATION) reactions involve the swapping of a non metal between two metals. The more reactive metal displaces the less reactive metal (or the more reactive metal is OXIDIZED and the less reactive metal REDUCED) • WORD EQUATION EXAMPLES OF THESE REACTIONS (plus colours!) • REDUCTION / OXIDATION or DISPLACEMENT • Lead Oxide + Carbon Lead + Carbon dioxide(Lead oxide is Reduced , Carbon is Oxidised)Copper Sulphate + Iron Copper + Iron Sulphate(Copper is displaced by more reactive iron) COMBINATION • Magnesium + Oxygen Magnesium Oxide • DECOMPOSITION • Copper Carbonate Copper Oxide + Carbon dioxide • NEUTRALISATION • Hydrochloric Acid + Sodium Hydroxide Sodium Chloride (Salt) + Water • REVERSIBLE • Hydrated Cobalt Chloride Cobalt Chloride (anhydrous) + water (This is a chemical test for water) Year 7 Revision booklet

8. 7G Particle model of solids, liquids and gases All matter is made up of particles Particle sizes vary from the smallest hydrogen atom to complex compounds made of thousands of different atoms. All particles move randomly This model is also called the kinetic theory of matter Gas Particles spread out, move fast no forces between particles, low density (high energy state) Liquid Particles very close together, move easily , strong forces between particles, high density (medium energy state) Solid Particles packed tightly together, only oscillation, very strong forces between particles, highest density (lowest energy state) To see this animated go to: http://www.harcourtschool.com/activity/states_of_matter/ Block Weighs 3330g B=5cm; L=11cm,H=6cm Density is a measure of how much mass is concentrated in a given volume Density of Block = Mass/ Volume =3300g/(5x11x6) cm³ =10g/cm³ M V D Year 7 Revision booklet REMEMBER “Mad Dogs Vomit”

9. 7H Solutions The key “S” Words SOLVENT: a liquid which dissolves a solute SOLUTE: a solid which dissolves in a liquid SOLUTION: the resultant mixture of soluble solute and solvent SATURATED: when a solution can hold no more solute at that temperature SUSPENSION: the resultant mixture of insoluble solute and solvent SOLUBILITY is a measure of how much solutedissolves in a given amount of solvent. (SOLUBILITY increases with temperature.) • Solutions are clear mixtures of one or more components. • The liquid is called the SOLVENT; the solid is called the SOLUTE. • If the solid dissolves it is SOLUBLE forming a SOLUTION. • If it doesn’t dissolve it is INSOLUBLE forming a SUSPENSION. • Similarly liquids can mix, (MISCIBLE liquids) to form solutions or not mix (IMMISCIBLE liquids) which form EMULSIONS • When a SOLUTION can hold no more SOLUTE, it is SATURATED. • The particle theory describes how particles “disappear” in a solution and how they can be seen in a suspension. • You can separate mixtures by using the differing physical properties of the components. • Differences in SOLUBILITY– FILTERING or CHROMATOGRAHY • Differences in Boiling point – EVAPORATION, CONDENSATION or DISTILLATION (simple or fractional) • CHROMATOGRAPHY: separating colours using a liquid • DISTILLATION: Evaporation following by condensation. Copper Sulphate Solution To see how salt (Sodium Chloride) dissolves in water go to: http://www.northland.cc.mn.us/biology/Biology1111/animations/dissolve.html Year 7 Revision booklet

10. 7G, H & F Particles, Solutions & Simple Chemical Reactions Select answers from these terms: Diffusion, Dissolving Soluble Insoluble Solvent Solute Suspension Miscible Immiscible Chromatography Distillation Evaporation Filtration Element Compound Combination Mixture Decomposition Precipitate Corrosion Electrolysis Electroplating Neutralization Combustion Year 7 Revision booklet

11. 7I Energy resources • NON RENEWABLE ENERGY • Fossil fuels are stores of energy formed from the remains of plants and animals that were alive millions of years ago. • Coal, oil and gas are fossil fuels. The are running out and cause global warming. • RENEWABLE ENERGY • Energy Resources which will not run out nor cause a problem with global warming! • Biomass (e.g. Wood), Geothermal (heat from the Earth’s molten core), Tidal energy (which comes from the movement of the tides), Nuclear energy (which comes from the splitting of uranium atoms), Hydroelectric power (which comes from the gravitational potential energy of water in mountains), Solar power (energy from the sun’s radiation), Wave power (from the energy stored up in waves), Wind power (harnessed by building wind turbines) • To find out more and test yourself go to: http://www.sciencemuseum.org.uk/exhibitions/energy/index.asp The Principle of the conservation of energy: “Energy cannot be created or destroyed it can only be transformed into a different form of energy”. ENERGY IS THE ABILITY TO DO WORK Year 7 Revision booklet

12. 7J Electricity • A simple series circuit (09) with 2 cells and 3 bulbs • All bulbs light, one break whole circuit stops, bulbs are dimmer as more bulbs added. • A complex parallel circuit (21) with 3 parallel arms • Each arm can be switched on/off, arms are same brightness as more arms added • Electricity will only flow in a completed circuit • Electricity is the flow of electrons through conductors. • All metals are good conductors • Non metals, wood, plastic are insulators • Current is measured in Amps using an Ammeter • The voltage of a cell is the pushing force which get the electrons moving. • Resistors block the flow of electrons. • You must learn the basic electrical symbols  • There are others e.g. Fuse, Reed Switch, Electromagnet, Diode, Light Dependent Resistor Year 7 Revision booklet

13. Speed is distance divided by time 2N ?N 7K Don’tThrow Stones D Moment =Force x Distance When a balance occurs Moments are equal So we can determine an unknown weight S T ? X 8=2X4 so ?= 1N 4cms 8cms Forces’ direction are indicated by an arrow Forces can only: Change shape, Change direction Speed things up Slow things down A Force is push or a pull A force will stretch a spring ; more force means more extension. This is used to measure forces in the Newton meter Gravity is the force of attraction between masses. On Earth Gravity acts on mass to produce weight. 1 kg becomes 10N, N= Newton, the unit of force is measured with a force or Newtonmeter. Bigger masses exert bigger gravitational pulls Other key forces: Upthrust, Friction, Air resistance (drag) Flying Parrots Attack F A P Pressure is force divided by area Year 7 Revision booklet

14. 7L THE SOLAR SYSTEM • Planets are held in their orbits because of the BALANCE between their GRAVITY and their SPEED. • The combination of the orbit and the tilt of the planet (Earth) give us SEASONS. • Planets also ROTATE on their AXIS giving us night and day and moving the shadows from long in the mornings to short at midday to long in the afternoon. • Although the Sun (and stars at night) appear to move across the sky during the course of the day (or night); their apparent movement is caused by the rotation of the Earth. • The Sun is LIGHT SOURCE, whilst the Moon orbits the Earth it reflects sunlight to us on Earth. This combination of ORBITING and Reflection give rise to the PHASES OF THE MOON. • The moon both ORBITS the Earth and spins on its own axis every 28 days. Consequently we only ever see one side of the moon. • The Earth ORBITS the Sun and because the Earth’s AXIS is tilted, this causes one hemisphere to point towards the sun (summer) and one hemisphere away from the sun (winter) as it moves around the Sun. • The order of the planets is: M V E MJ S U NP • (Rocky) (Gas giants) Rocky • Stars do not move but appear to circle the earth because of its rotation. • Key Words: • ORBIT: To path around a larger object, the Earth orbits the sun, the moon orbits the Earth • AXIS: an imaginary line about which the object (Earth) rotates or spins • WAXING: getting bigger, applied to the visible part of the moon • WANING: getting smaller, applied to the visible part of the moon • NEW, CRESCENT, HALF, GIBBOUS, FULL: the order of the PHASES OF THE MOON: when it is WAXING • STAR a stationary large luminous object • GALAXY millions of solar systems, our galaxy is called the Milky Way. • UNIVERSE all galaxies, matter, everything! • GRAVITY theforce of attraction between 2 large bodies, it increases as the bodies get bigger and closer Year 7 Revision booklet

15. The Earth rotates (spins) on an Axis. This gives us day & night. The axis is tilted relative to a line to the sun and this gives us The seasons of the year, which different amounts of sunlight 7L Groups of stars are called constellations. Orion is a good example Planets orbit stars because of the balance Between their speed and The attractive gravitational force The moon is a satellite. It reflects sunlight, as it orbits the Earth, every 28 days, we see more or less of its surface, this called phases of the moon. Total surface = Full Moon No Surface = New moon The SOLAR SYSYTEM SPACE Planets orbits are circular,with the more distant planets taking much longer to orbit the sun The Universecontains all matter. It is made up of Galaxies, which contain millions of Stars, each of which has a Star (or Solar) system, each of which has planets, which usually have satellites or moons. Starsare massive, stationary and give out light; Planetsorbit stars, are smaller and reflect light The Earth, Distance to moon, The Moon (all same scale) Year 7 Revision booklet