Diet and excercise:Balanced diet includes everything needed to keep the body healthyDifferent people need different amounts of energy because the metabolic rate varies from person to personIf the energy taken in is less than the energy used the person will lose mass. the more excercise you do, the more food you needWeight problems:More food you eat then your mass will increasePeople who are fat are obese, can lead to type 2 diabetesAlso unhealthy to be underwieghtExcercise helps to keep the body healthyInheritance, exercise and healthInherited factors affect our health include metabolic rates and cholesterol levelsPeople who exercise regularly are usually healthier than those who take little exercisePathogens and disease:The are microogranisms that cause infectious disease, usually either bacteria or virusPathogens reproduce quickly inside the body and may produce toxinsViruses reproduce inside cells and damage themWashing hands removes pathogens from them, Semmelweiss was the first doctor to realise thisDefence mechanisms:Body prevents most pathogens from getting inPathogens which enter the body can be destroyed by white blood cellsThey can ingest pathogens, produce antibodies to help destroy particular pathogens, produce antitoxins to counteract the toxins Using drugs to treat disease:Some medicines may relieve the symptoms of disease but not kill the pathogens that cause itAntbiotics cure bacterial diseases by killing the bacteria inside your body but cannot destroy virusesViruses are difficult to destroy because they reproduce inside body cellsGrowing and investigating bacteriaBacteria can be grown on agar jelly, all materials and equipment must be sterilised, ensures that unwanted microorganisms do not infect the cultureUncontaminated cultures can be used to investigate the effect of antibiotics and disinfectants on the bacteriaChanging Pathogens:If a pathogen changes by mutation the new strain may spread rapidly, some can cause epidemics and pandemicsSome bacteria have developed resistance to antibiotics by natural selectionImmunity:Wide range of vaccines are given to immunise people against diseaseVaccines contain dead or inactive pathogens, can protect against both bacterial and viral pathogens, encourage your white blood cells to produce antibodies that destroy the pathogensHow to deal with disease:Vaccination protects individuals and society from the effects of diseaseTreatment of disease has changed as our understanding of antibiotics and immunity has increased

Responding to change:Nervous system allows humans to react to their surrondings and coordinates behaviourReceptors detect external stimuliElectrical impulses Sensory neurons to and motor neurons away pass to the brain along neuronsBrain coordinates responseEffector organs muscles or glands secreting or contractingReflex actions:Actions are rapid, automatic responses to a stimulusReflexes protect us from damageHormones and menstrual cycle:Menstrual cycle take 28 days with ovulation 14 days in cycle controlled by three hormones: FSH made by the pituitary gland and causes the egg to mature and oestragen to be produced, Oestrogen produced in ovaries inhibits production of FSH. Stimulates production of LH stimulates the womb lining to develop to recieve the egg and made in pituitary gland.The artificial control of fertility:Contraceptive pills contain oestrogen and porgesterone to inhibit FSHFSH can be given to a woman to help her to produce eggsControlling conditions:It is very important that the internal conditions of the body are kept within certain limits. The nervous system and hormones help to do this.Water and ion content, as well as temperature and blood sugar level are all carefully controlledHormones and the control of plant growth:Plants respond to light, gravity and moistureShoots grow towards light and away from gravityRoots grow toward gravity and waterHormones such as auxin cause these changesPlant hormones have uses in agriculture and horticultureUsing hormones:Important to evaluate the advantages and disadvantages of using hormones to control fertility: can stop unwanted organisms, long time use for women can have side effects, incorrect use of plant hormones can damage the environment

Developing new medicines:New drugs must be throughly tested before they are sold as medicinesDrugs are tested to see if they work, to find out if they are toxic and to see if they cause side effectsThalidomide was developed as sleeping dug but not tested for preventing morning sickness, so some babies had birth defectsHow effective are medicines?Statins are drugs which lower cholesterol levels. Their use has lowered cardiovascular disease in the population by over 40%Double blind trials should be used to heck if both non-prescribed an prescribed drugs actually workDrugs:Chemicals which alter the body's chemistry, you can become addicted to some drugsboth illegal and legal ones, such as alcohol and tobacco, may harm your bodyChemicals in cannabis may cause mental health problems and lead to using hard drugsHeroin and cocaine are very addictiveLegal and illegal drugs:Many recreational drugs cause changes in the brain and nervous system, some are very harmful Recreational drugs may be legal or illegalMore people use legal drugs, so their impact on health is greater than that of illegal drugsDoes cannabis lead to hard drugs?Cannabis is an illegal drug which must be bought from drug dealers. This can put the user in contact with hard drugsChemicals in cannabis smoke may cause mental illness in some people, mainly teenagersDrugs in sport:Some athletes use drugs to make them perform betterSteroids are one type one of performance-enhancing drugUse of performance-enhancing drugs is considered unethical by most people and can permanently harm body and even lead to death

Adapt and survive:All organisms need supply of materials to survive and reproduce, are adapted to survive in the conditions in which they normally liveMicroorganisms have a wide range of adaptations which enable some of them of in extreme conditions(extremophiles)Adaptations in animals:Animals adaptations help them to survive in the conditions where they normally liveanimals in cold areas are usually large with a small surface area: volume ratioanimals in hot areas may have a large surface area: volume ratiocoat colour may change in different seasonsAdaptations in plants:Plants lose water vapour from the leaf surfaceTo survive in dry conditions plants have adaptations to reduce the surface area of leaves, and to have tissues which store water and extensive root systemscompetition in animals:animals often compete with each other for food, mates and territorywell adapted animals are good competitorscompetition in plants:Plants compete with each other for light, water and mineral ions from the soilWell adapted plants are good competitorsHow do you survive?Organisms have adaptations which enable them to survive in the conditions in which they normally livePlants often compete with each other for light, water and nutrients from the soilMeasuring environmental change:Changes in environment affect the distribution of living organismsThese changes can be measured using non-living indicatorsLiving organisms can be used as pollution indicatorsImpact of change:Distribution of living organisms is affected by the changes in non-living and living factorsData on the effect of environmental change is not always easy to interpret

Pyramids of biomass:Radiation from the sun is the main source of energy for living organismsGreen plants and algae capture light energy during photosynthesisBiomass is the dry mass of living material in an organismThe biomass at each stage in a food chain is less than at the previous stage.Energy transfer:There is less biomass and energy availabe to each successive stage in a food chainMaterials are used at each stage and energy may be transferred to the surrondingsDecay processesLiving organisms remove materials from the environment which are returned when the organism diesMicroorganisms decay waste and dead plants and animalsDecay is quicker in warm, moist,aerobic conditionsProcesses which use materials must be balanced by those which release themThe Carbon Cycle:Constant cycling of carbon in nature is known as the carbon cyleDuring photosynthesis carbon dioxide is removed from the atmosphereProcesses of respiration and combustion return carbon dioxide to the atmosphereRecycling organic waste:Recycling organic kitchen and garden wate is necessary to: reduce landfill, reduce methane production, recycle minerals and nutrients in the waste.Various methods of recycling organic waste

Variation, reproduction and new technologyInheritance:Organisms have similar characteristics to their parents Genes are passed in sex cells from parents to offspringGenes control the characteristics of your bodyTypes of repoduction:In asexual reproduction there is no joining of gametesClones are produced by asexual reproductionClones are identical copies of one parentSexual reproduction involves tow parents and leads to variety in the offspring gives some better chance to surviveGenetic and environmental differences:Differences in individuals of the same kind can be due to their genes, the environment or bothclones may have some differences due to environmental causesCloningPlant clones can be made quickly by taking cuttings from mature plantsTissue culture is a newer method of cloning it's taking small groups of cells from part of a plant and growing them under special conditionsAnimals can be cloned by transplanting cloned embryosAdult cell cloning:Scientists have adult cells to clone amimals such as dolly the sheepNucleas of an adult cell is transplanted into and empty egg cell, cell is given an mild eletric shock fusion occures implanted into another animal. When animal delevops has the genetic material of the original adult cell.Genetic engineering:Genetic engineering is used to transfer a gene from one organism to another.Enzymes are used to cut out a gene from a human chromosome and then insert it into a bacterial cellgenes can be transferred to the cells of animals and plants at an early stage in their developmentMaking choices about technology:Advantages and disadvantages in the use of cloning and genetic engineeringIssues can be economic, social or ehtical

Evolution:Theories of evolution:All species of living things have evolved from simple life forms. These simple forms developed more than 3 billion yrs agoDarwin's theory states that evolution takes place by a process of natural selection: mutation - variation - best adapted- survive - breed- pass on genesAccepting Darwin's Ideas:Darwin's theory of evolution was only gradually acceptedas later able to be proved did not no about genes and geneticsNatural selection:Natural selection works because the fittest organisms survive to breedIf a gene changes, the new characteristic may enable the organism to better surviveclassification and evolution:We can classify organisms into groups by comparing their similarites and differencesClassification helps us to understand evolutionary and ecological relationships

Keeping Healthy

Co ordination and contrrol

Medicene and drugs

Adaption for survival

Energy in Biomass