Biology Revision

Majeed Thaika Year 10-11   Contents 1 Cells   pg-05 -Animal and plant cells (pg-05) -Specialised cells (pg-06) -diffusion (pg-07) -osmosis (pg-08) 2 Plants . pg-09 -photosynthesis (pg-09) -Factors affecting photosynthesis (pg-10) -Plants and minerals (pg-11) 3 Food Chains and Cycles pg-12 -Food chain (pg-12) -Energy transfer (pg-13) -Pyramids of biomass (pg-15) -efficiency of food production (pg-15) -calculating energy efficiency (pg-16) Shorter food chains (pg-16) carbon cycle (pg-17) 4Enzymes and Digestion   pg-18 -What are enzymes? (Pg-18) -Temperature and enzymes (Pg-18) -Ph and enzymes (Pg-19) -enzymes and respiration (Pg-20) -digestive system (Pg-20) -Enzymes and digestion (Pg-21) -Other substances in digestion (Pg-22) -Enzymes in industry (Pg-23) 5Homeostasis   pg-24 -Removing waste products (Pg-24) -Controlling blood glucose (Pg-25) -Diabetes (Pg-25) -Temperature regulation (Pg-26) – Temperature regulation – Higher (Pg-26) 6Hormones   pg-27 -Hormones a nd glands (pg-28) hormones in the menstrual cycle (pg-29) -Controlling fertility (pg-31) 7The Nervous System   pg-31 -receptors and effectors (pg-31) -Neurones (pg-33) -Reflex action (pg-34) 8Defending against infection   pg-35 -pathogens-bacteria (pg-35) -pathogens-virus (pg-36) -white blood cells (pg-36) -more about white blood cells (pg-37) -vaccination (pg-38) -antibiotics (pg-38) 9Diet and Exercise   pg-40 -nutrients (pg-40) -metabolic rate(pg-41) -the right amount of food (pg-41) -cholesterol(pg-42) -salt (pg-43) 10Adaptation   pg-43 -Adaptation-cold climates (pg-43) -Adaptation-hot climates (pg-44) 11Characteristics and Classification   pg-45 -genetic engineering (pg-45) -selective breeding (pg-45) -changing the characteristics of a species (pg-46) -classification (pg-47) -difficulties with classification (pg-48) 12The Heart   pg-49 -the circulatory system (pg-49) -arteries and veins (pg-50) -the heart (pg-50) -causes of heart disease (pg-51) 13Extra   pg-51 -se x hormones (pg-51) competition (pg-52) -The nitrogen cycle -the water cycle Cells All animals and plants are made of cells. Animal cells and plant cells have features in common, such as a nucleus, cytoplasm, cell membrane, mitochondria and ribosomes. Plant cells also have a cell wall, and often have chloroplasts and a permanent vacuole. Note that cells may be specialized to carry out a particular function. Dissolved substances pass into and out of cells by diffusion. Water passes into and out of cells by osmosis. Animal and plant cells Function of cells which animal and plant cells have in common:- Part| Function| ucleus| contains genetic material, which controls the activities of the cell| cytoplasm| most chemical processes take place here, controlled by enzymes| cell membrane| controls the movement of substances into and out of the cell| mitochondria| most energy is released by respiration here| ribosomes| protein synthesis happens here| Extra parts of plant cells:- Part| Function | cell wall| strengthens the cell| chloroplasts| contain chlorophyll, which absorbs light energy for photosynthesis| permanent vacuole| filled with cell sap to help keep the cell  turgid|Diagram: Generalized animal and plant cell Specialised cells Cells may be specialized for a particular function. Their structure will allow them to carry this function out. Here are some examples: Examples of the functions of cells:- Cell| Function| Adaption| Leaf cell| Absorbs light energy for photosynthesis| Packed with chloroplasts. Regular shaped, closely packed cells form a continuous layer for efficient absorption of sunlight. | Root hair cell| Absorbs water and mineral ions from the soil| Long ‘finger-like' process with very thin wall, which gives a large surface area. |Sperm cell| Fertilizes an egg cell – female gamete| The head contains genetic information and an enzyme to help penetrate the egg cell membrane. The middle section is packed with mitochondria for energy. The tai l moves the sperm to the egg. | Red blood cells| Contain haemoglobin to carry oxygen to the cells. | Thin outer membrane to let oxygen diffuse through easily. Shape increases the surface area to allow more oxygen to be absorbed efficiently. No nucleus, so the whole cell is full of haemoglobin. | Diffusion Dissolved substances have to pass through the cell membrane to get into or out of a cell.Diffusion is one of the processes that allow this to happen. Diffusion  occurs when particles spread. They move from a region where they are in high concentration to a region where they are in low concentration. Diffusion happens when the particles are free to move. This is true in gases and for particles dissolved in solutions. Particles diffuse down a concentration gradient, from an area of high concentration to an area of low concentration. This is how the smell of cooking travels around the house from the kitchen, for example. Examples of diffusion Location| Particles move| From| To|Gut| digested food products| gut cavity| blood in capillary of villus| Lungs| oxygen| alveolar air space| blood circulating around the lungs| Two examples of diffusion down concentration gradients:- Remember, particles continue to move from a high to a low concentration while there is a  concentration gradient. In the lungs, the blood will continue to take in oxygen from the alveolar air spaces provided the concent-ration of oxygen there is greater than in the blood. Oxygen diffuses across the alveolar walls into the blood, and the circulation takes the oxygen-rich blood away. OsmosisWater can move across cell membranes because of osmosis. For osmosis to happen you need: * two solutions with different concentrations * a partially permeable membrane to separate them Partially permeable membranes let some substances pass through them, but not others. The animation shows an example of osmosis. Osmosis is the movement of water from a less concentrated solution to a more concentrated soluti on through a partially perm-eable membrane. The picture above shows how osmosis works. Eventually the level on the more concentrated side of the membrane rises, while the one on the less concentrated side falls.When the concentration is the same on both sides of the membrane, the movement of water molecules will be the same in both directions. At this point, the net exchange of water is zero and there is no further change in the liquid levels. Osmosis is important to plants. They gain water by osmosis through their roots. Water moves into plant cells by osmosis, making them  turgid  or stiff so they that able to hold the plant upright. Plants Green plants absorb light energy using chlorophyll in their leaves. They use it to react carbon dioxide with water to make a sugar called glucose.The glucose is used in respiration, or converted into starch and stored. Oxygen is produced as a by-product. This process is called photosynthesis. Temperature, carbon dioxide concentration and li ght intensity are factors that can limit the rate of photosynthesis. Plants also need mineral ions, including nitrate and magnesium, for healthy growth. They suffer from poor growth in conditions where mineral ions are deficient. Photosynthesis Photosynthesis  is the chemical change which happens in the leaves of green plants. It is the first step towards making food – not just for plants but ultimately every animal on the planet.During this reaction,  carbon dioxide  and water are converted into glucose and oxygen. The reaction requires  light energy, which is absorbed by a green substance called chlorophyll. Cross-section through a leaf cell Photosynthesis takes place in leaf cells. These contain chloroplasts, which are tiny objects containing chlorophyll. The equation for photosynthesis is:- Plants absorb water through their roots, and carbon dioxide through their leaves. Some glucose is used for respiration, while some is converted into insoluble starch  for sto rage. The stored starch can later be turned back into glucose and used in respiration.Oxygen is released as a by-product of photosynthesis. Factors limiting photosynthesis Three factors can limit the speed of photosynthesis – light intensity, carbon dioxide concentration and temperature. Light intensity -Without enough light, a plant cannot photosynthesise very quickly, even if there is plenty of water and carbon dioxide. -Increasing the light intensity will boost the speed of photosynthesis. Carbon dioxide concentration Sometimes photosynthesis is limited by the concentration of carbon dioxide in the air. Even if there is plenty of light, a plant cannot photosynthesise if there is insuff-icient carbon dioxide.Temperature -If it gets too cold, the rate of photosynthesis will decrease. Plants cannot photosynthesise if it gets too hot. -If you plot the rate of photosynthesis against the levels of these three limiting factors, you get graphs like the ones above. -In practice, an y one of these factors could limit the rate of photosynthesis. Maximizing growth Farmers can use their knowledge of these limiting factors to increase crop growth in greenhouses. They may use artificial light so that photosynthesis can continue beyond daylight hours, or in a higher-than-normal light intensity.The use of paraffin lamps inside a greenhouse increases the rate of photosynthesis because the burning paraffin produces carbon dioxide and heat too. Plants and minerals Plants need to take in a number of elements to stay alive. The most important are: * carbon * hydrogen * oxygen Plants get hydrogen and oxygen from water in the soil, and carbon and oxygen from carbon dioxide and oxygen in the atmosphere. Water and carbon dioxide are used to synthesise food during photosynthesis. Oxygen is used to release energy from food during respiration. In addition to these three elements, plants need a number of minerals for healthy growth.These are absorbed through the roots as mineral i ons dissolved in the soil water. Two important mineral ions needed by plants are: * Nitrate  Ã¢â‚¬â€œ for making amino acids, which are needed to make proteins * Magnesium  Ã¢â‚¬â€œ for making chlorophyll If a plant does not get enough minerals, its growth will be poor. It will suffer from deficiency symptoms: * deficient in nitrate – it will suffer from stunted growth * deficient in magnesium – it's leaves will turn yellow The tomato plant on the left is healthy; the one on the right is growing in conditions where mineral ions are deficient Food Chains and CyclesFood chains show the feeding relationships between living things. Pyramids of biomass reveal the mass of living material at each stage in a chain. The amount of material and energy decreases from one stage to the next. Food production is more efficient if the food chain is short, or if energy losses from animals are reduced. The carbon cycle shows how carbon moves from the atmosphere, through various anima ls and plants, then back to the atmosphere again. Food chains A  food chain  shows what eats what in a particular habitat. For example, grass seed is eaten by a vole, which is eaten by a barn owl.The arrows between each item in the chain always point in the direction of energy flow – in other words, from the food to the feeder. The Sun is the ultimate source of energy for most communities of living things. Green plants absorb some of the Sun’s light energy to make their own food by photosynthesis. The other organisms in a food chain are consumers, because they all get their energy and biomass by consuming – eating – other organisms. It helps if you can recall the meaning of some common words used with food chains. Common words used with food chains and their meaning Word| Meaning|Producers| Green plants – they make food by photosynthesis. | Primary consumers| Usually eat plant material – they are herbivores. For example rabbits, caterpil lars, cows and sheep. | Secondary consumers| Usually eat animal material – they are carnivores. For example cats, dogs and lions. | Predators| Kill for food. They are either secondary or tertiary consumers| Prey| The animals that predators feed on. | Scavengers| Feed on dead animals. For example, crows, vultures and hyenas are scavengers. | Decomposers| Feed on dead and decaying organisms, and on the undigested parts of plant and animal matter in faeces. Energy transfer Energy is transferred along food chains from one stage to the next. But not all of the energy available to organisms at one stage can be absorbed by organisms at the next one. The amount of available energy decreases from one stage to the next. Some of the available energy goes into growth and the production of offspring. This energy becomes available to the next stage, but most of the available energy is used up in other ways: * energy released by respiration is used for movement and other life processes, and is eventually lost as heat to the surroundings energy is lost in waste materials, such as faeces All of the energy used in these ways returns to the environment, and is not available to the next stage. The animation shows how the level of available energy goes down as it is transferred through a temperate forest food chain. Most food chains are pretty short. There are rarely more than four stages, because a lot of energy is lost at each stage. Pyramids of biomass Biomass  means the mass of living material at a stage in a food chain. The biomass goes down as you go from one stage to the next, just like the amount of energy.A  pyramid of biomass  is a chart, drawn to scale, showing the biomass at each stage in a food chain. The bars become narrower as you reach the top. This pyramid of biomass is for the food chain: Oak tree > caterpillar > blue tit > sparrowhawk Note that you do not need to draw the organisms. But you must draw your pyramid of biomass to scale. Each bar should be labelled with the name of the organism. Efficiency of food production The efficiency of food production can be improved by reducing the amount of energy lost to the surroundings. This can be done by: * preventing animals moving around too much keeping their surroundings warm Mammals and birds maintain a constant body temperature using energy released by respiration. As a result, their energy losses are high. Keeping pigs and chickens in warm sheds with little space to move around allows more efficient food production. But this raises moral concerns about the lives of such animals. In reality, a balance must be reached between the needs of farmers and consumers and the welfare of the animals. Calculating energy efficiency This bullock has eaten 100 kJ of stored energy in the form of grass, and excreted 63 kJ in the form of faeces, urine and gas.The energy stored in its body tissues is 4 kJ. So how much has been used up in respiration? The energy released by respiration = 100 â₠¬â€œ 63 – 4 = 33 kJ Only 4 kJ of the original energy available to the bullock is available to the next stage, which might be humans. The efficiency of this energy transfer is: Efficiency = 4/100 x 100 = 4% Shorter food chains Food production is more efficient if the food chain is short, because a higher percentage of energy is available to us. The carbon cycle All cells – whether animal, plant or bacteria – contain  carbon, because they all contain proteins, fats and carbohydrates.Plant cell walls, for example, are made of cellulose – a carbohydrate. Carbon is passed from the atmosphere, as carbon dioxide, to living things, passed from one organism to the next in complex molecules, and returned to the atmosphere as carbon dioxide again. This is known as the carbon cycle. Removing carbon dioxide from the atmosphere Green plants remove carbon dioxide from the atmosphere by  photosynthesis. The carbon becomes part of complex molecules such as proteins, f ats and carbohydrates in the plants. Returning carbon dioxide to the atmosphere Organisms return carbon dioxide to the atmosphere by  respiration.It is not just animals that respire. Plants and microorganisms do, too. Passing carbon from one organism to the next When an animal eats a plant, carbon from the plant becomes part of the fats and proteins in the animal. Microorganisms and some animals feed on waste material from animals, and the remains of dead animals and plants. The carbon then becomes part of these microorganisms and detritus feeders. Materials from living things decay because they are digested by microorganisms. This process happens faster in warm, moist conditions with plenty of oxygen. Decay can be very slow in cold, dry conditions, and when here is a shortage of oxygen. Enzymes and digestion Enzymes are biological catalysts. There are optimum temperatures and  pH values at which their activity is greatest. Enzymes are also proteins, and usually denatured above about 45? C. Enzymes are important in respiration. Aerobic respiration releases energy from glucose. What are enzymes? Enzymes are biological catalysts – catalysts are substances that increase the rate of chemical reactions without being used up. Enzymes are also  proteins  that are folded into complex shapes that allow smaller molecules to fit into them.The place where these  substrate  molecules fit is called the  active site. The pictures show how this works. In this example, two small molecules join together to make a larger one. If the shape of the enzyme changes, it’s active site may no longer work. We say the enzyme has been  denatured. They can be denatured by high temperatures or extremes of  pH. Note that it is wrong to say the enzyme has been killed. Although enzymes are made by living things, they are proteins, and not alive. Temperature and enzymes As the temperature increases, so does the rate of reaction. But very high temperatures denature enzymes.The graph shows the typical change in an enzyme's activity with increasing temperature. The enzyme activity gradually increases with temperature until around 37? C, or body temperature. Then, as the temperature continues to rise, the rate of reaction falls rapidly, as heat energy denatures the enzyme. Temper-ature and enzyme activity PH and enzymes Changes in pH alter an enzyme’s shape. Different enzymes work best at different pH values. The optimum pH for an enzyme depends on where it normally works. For example, intestinal enzymes have an optimum pH of about 7. 5. Enzymes in the stomach have an optimum pH of about 2. H and enzyme activity Enzymes and respiration Enzymes in cells catalyse photosynthesis, protein synthesis – joining amino acids together, and aerobic respiration. Aerobic respiration Respiration is not the same thing as breathing. That is more properly called ventilation. Instead, respiration is a chemical process in which energy is released fro m food substances, such as glucose – a sugar. Aerobic  respiration needs oxygen to work. Most of the chemical reactions involved in the process happen in tiny objects inside the cell cytoplasm, called mitochondria. This is the equation for aerobic respiration:Glucose + oxygen >  carbon dioxide + water (+ energy) The energy released by respiration is used to make large molecules from smaller ones. In plants, for example, sugars, nitrates and other nutrients are converted into amino acids. Amino acids can then join together to make proteins. The energy is also used: * to allow muscles to contract in animals * to maintain a constant body temperature in birds and mammals Enzymes are important in digestion. Digestion is the breakdown of carbohydrates, proteins and fats into small soluble substances that can be absorbed into the blood.Lipases and proteases are used in biological detergents, and enzymes are used in the manufacture of food and drink. The digestive system Digestio n is the breakdown of large molecules into smaller, soluble molecules that can be absorbed into the body. Digestion happens inside the gut, and relies on enzymes. This diagram will show you of the main parts of the gut: Enzymes and digestion The enzymes involved in respiration, photosynthesis and protein synthesis work inside cells. Other enzymes are produced by specialised cells and released from them; the digestive enzymes are like this. They pass out into he gut, where they catalyse the breakdown of food molecules. Different enzymes Different enzymes catalyse different digestion reactions. Enzymes and their reactions catalysed enzyme| reaction catalysed| amylase| starch > sugars| protease| proteins > amino acids| lipase| lipids   >   fatty acids + glycerol| Amylase is an example of a carbohydrase. Lipids are fats and oils. Different parts of the gut Different parts of the gut produce different enzymes. Where enzymes are produced enzyme| where produced| amylase| salivary gland s, pancreas, small intestine| protease| stomach, pancreas, small intestine| ipase| pancreas, small intestine| Summary Overall, this means that: * Amylase catalyses the breakdown of starch into sugars in the mouth and small intestine. * Proteases catalyse the breakdown of proteins into amino acids in the stomach and small intestine. * Lipases catalyse the breakdown of fats and oils into fatty acids and glycerol in the small intestine. Other substances in digestion You should recall that different enzymes work best at different pH values. The digestive enzymes are a good example of this. Enzymes in the stomach The stomach produces  hydrochloric acid.This helps to begin digestion, and it kills many harmful microorganisms that might have been swallowed along with the food. The enzymes in the stomach work best in  acidic  conditions – in other words, at a low pH. Enzymes in the small intestine After the stomach, food travels to the small intestine. The enzymes in the small i ntestine work best in  alka-line  conditions, but the food is acidic after being in the stomach. A substance called  bile  neutralises the acid to provide the alkaline conditions needed in the small intestine. Bile and enzyme production in the liver and pancreas Enzymes in industry Enzyme namesThe names of the different types of enzymes usually end in the letters  -ASE. Three of the most common enzymes with their chemical actions are: * lipase  Ã¢â‚¬â€œ breaks down fats * protease  Ã¢â‚¬â€œ breaks down proteins * carbohydrase  Ã¢â‚¬â€œ breaks down carbohydrates Enzyme uses Enzymes allow certain industrial processes to be carried out at normal temperatures and pressures, thereby reducing the amount of energy and expensive equipment needed. Enzymes are also used in the home, for example, in ‘biological' detergents. The table shows some common enzyme uses you should be familiar with. Uses of enzymes Enzyme| Use| rotease| used to pre-digest proteins during the manu facture of baby foods| lipase| used – together with protease – in biological detergents to break down – digest – the substances in stains into smaller, water soluble substances| carbohydrase| used to convert starch syrup, which is relatively cheap, into sugar syrup, which is more valuable – for example, as an ingredient in sports drinks| isomerase| used to convert glucose syrup into fructose syrup – fructose is sweeter than glucose, so it can be used in smaller amounts in slimming foods| Homeostasis The conditions inside the body must be controlled within narrow limits.This is called homeostasis. These conditions include water content, ion content, body temperature and blood glucose concentration. The thermoregulatory centre is the part of the brain that monitors and controls body temperature. The pancreas meanwhile monitors and controls blood glucose concentration. It produces a hormone called insulin that reduces blood glucose levels. Diab etes is a disease which can be caused by insufficient insulin. Removing waste products Waste products must be removed from the body. If they are not, they will increase in concentration and may interfere with chemical reactions or damage cells.Waste products that must be removed include carbon dioxide and urea. Waste product| Why is it produced? | How is it removed? | carbon dioxide| it is a product of aerobic respiration| through the lungs when we breathe out| urea| it is produced in the liver when excess amino acids are broken down| the kidneys remove it from the blood and make urine, which is stored in the bladder temporarily| Production and removal of waste products Water enters the body through food and drink. It is also a product of aerobic respiration in cells. If the amount of water in the body is wrong, cells can be damaged because too much water enters or leaves them.The pictures show how the amount of water lost as urine is controlled: Controlling blood glucose The pancre as and insulin The  pancreas  monitors and controls the concentration of  glucose  in the blood. It produces a hormone called  insulin. Insulin causes glucose to move from the blood into cells. It lowers the blood glucose concentration if it has become too high. This can happen after eating a meal that is rich in carbohydrates (for example, sweets, potatoes, bread, rice or pasta). The pictures show how this works. Diabetes Diabetes is a disease where the concentration of  glucose  in the blood is not controlled properly by the body.In  type 1 diabetes, the  pancreas  does not produce eno-ugh  insulin. This can lead to high levels of glucose in the blood, which can be fatal. Types of Diabetes There are two types of treatment for diabetes: * Careful monitoring of food intake, with particular care taken over carbohydrates – which are digested into glucose. * Injecting insulin into the blood before meals. The extra insulin causes glucose to be taken up by th e liver and other tissues. Cells get the glucose they need for respiration, and the blood glucose concentration stays normal. Temperature regulation Human  enzymes  work best at 37?C, so the body’s temperature is controlled. A part of the brain called the  thermoregulatory centre  monitors and controls body temperature. It gathers information as nerve impulses from  temperature receptors  in: * the brain – these are sensitive to the temperature of the blood flowing there * the skin – these are sensitive to skin temperature Sweating Sweating is one way to help cool the body. We sweat more in hot conditions, so more water is lost from the body. This water must be replaced through food or drink to maintain the balance of water in the body. Ions such as sodium ions and chloride ions are also lost when we sweat.They must be replaced through food and drink. If the body’s ion content is wrong, cells can be damaged. Temperature regulation – hig her If you become too hot or too cold, there are several ways in which your temperature can be controlled. They involve sweating, shivering, skin capillaries and hairs. Too hot When we get too hot: * Sweat glands in the skin release more sweat. This evaporates, removing heat energy from the skin. * Blood vessels leading to the skin capillaries become wider – they  dilate  Ã¢â‚¬â€œ allowing more blood to flow through the skin, and more heat to be lost. Too cold When we get too cold: * Muscles contract rapidly – we shiver.These contractions need energy from respiration, and some of this is released as heat. * Blood vessels leading to the skin capillaries become narrower – they  constrict- letting less blood flow through the skin and conserving heat in the body. The hairs on the skin also help to control body temperature. They lie flat when we are warm, and rise when we are cold. The hairs trap a layer of air above the skin, which helps to insulate the skin a gainst heat loss. Controlling temperature Too cold| Too hot| | | A  Ã¢â‚¬â€œ Hair muscles pull hairs on end. B  Ã¢â‚¬â€œ Erect hairs trap air. C  Ã¢â‚¬â€œ Blood flow in capillaries decreases. | D  Ã¢â‚¬â€œ Hair muscles relax.Hairs lie flat so heat can escape. E  Ã¢â‚¬â€œ Sweat secreted by sweat glands. Cools skin by evaporation. F  Ã¢â‚¬â€œ Blood flow in capillaries increases. | Remember: Capillaries do not move up and down inside the skin. Temperature is regulated by controlling the amount of blood which flows through the capillaries. Hormones Hormones are chemical substances that help to regulate processes in the body. Hormones are secreted by glands and travel to their target organs in the bloodstream. Several hormones are involved in the female menstrual cycle. Hormones can be used to control human fertility and have advantages and disadvantages. Hormones and glandsHormones are  chemicals secreted by glands  in the body. Different hormones affect different target organs. The bloodstream transports hormones from the glands to the target organs. Hormones regulate the functions of many cells and organs The target organ and effects of glands and hormones Gland| Hormone| Target organs| Effect| adrenal gland| adrenalin| vital organs, e. g. liver and heart| Prepares body for action – ‘fight or flight'. | ovary| oestrogen| ovaries, uterus, pituitary gland| Controls puberty and the menstrual cycle in females; stimulates production of LH and suppresses the production of FSH in the pituitary gland. ovary| progesterone| uterus| Maintains the lining of the womb – suppresses FSH production in the pituitary gland. | pancreas| insulin| liver| Controls blood sugar levels. | pituitary gland| anti-diuretic hormone (ADH)| kidney| Controls blood water level by triggering uptake of water in kidneys. | pituitary gland| follicle stimulating hormone (FSH)| ovaries| Triggers egg ripening and oestrogen production in ovaries. | pituitary gland| lut einising hormone (LH)| ovaries| Triggers egg release and progesterone production in ovaries. | testes| testosterone| male reproductive organs| Controls puberty in males. |Hormones in the menstrual cycle The menstrual cycle in women is a recurring process in which the lining of the uterus – womb – is prepared for pregnancy, and if pregnancy does not happen, the lining is shed at menstruation. Several  hormones  control this cycle, which includes controlling the release of an egg each month from an ovary, and changing the thickness of the uterus lining. These hormones are secreted by the ovaries and pituitary gland. FSH The hormone FSH is secreted by the pituitary gland. FSH makes two things happen: 1. it causes an egg to mature in an ovary 2. it stimulates the ovaries to release the hormone oestrogen OestrogenThe hormone oestrogen is secreted by the ovaries. Oestrogen makes two things happen: 1. it stops FSH being produced – so that only one egg matures in a cycle 2. it stimulates the pituitary gland to release the hormone LH LH The hormone LH causes the mature egg to be released from the ovary. This image shows how the level of oestrogen changes during the menstrual cycle. Progesterone is another hormone secreted by ovaries: it maintains the lining of the uterus and stays high during pregnancy. Hormone levels during the menstrual cycle Controlling fertility Human fertility is controlled by  hormones.This means that knowledge of hormones can be used to decide to increase, or reduce, the chances of fertilisation and pregnancy. Oral contraceptives Contraceptive pills The oral contraceptive, ‘the pill', greatly reduces the chances of mature eggs being produced. The pill contains oestrogen, or oestrogen and progesterone. These hormones inhibit the production of FSH, which in turn stops eggs maturing in the ovaries. Fertility treatment Some women have difficulty becoming pregnant because they don't produce enough FSH to allow their e ggs to mature. ‘Fertility drugs' contain FSH, which stimulates eggs to mature in the ovary. The nervous systemThe nervous system allows the body to respond to changes in the environment. This is a process usually coordinated by the brain. Reflex actions are extra-rapid responses to  stimuli, and this process also involves the nervous system, but bypasses the brain. Receptors and effectors Receptors Receptors are groups of specialised cells. They can detect changes in the environment, which are called  stimuli, and turn them into electrical impulses. Receptors are often located in the  sense organs, such as the ear, eye and skin. Each organ has receptors sensitive to particular kinds of stimulus. Receptors sense organs| receptors sensitive to|Skin| touch, pressure, pain and temperature| Tongue| chemicals in food| Nose| chemicals in the air| Eyes| light| Ears| sound and position of the head| The central nervous system – CNS – in humans consists of the brain a nd spinal cord. When a receptor is stimulated, it sends a signal along the nerve cells – neurones – to the brain. The brain, then co-ordinates the response. Effectors An effector is any part of the body that produces the response. Here are some examples of effectors: * a muscle contracting to move the arm * a muscle squeezing saliva from the salivary gland * a gland releasing a  hormone  into the blood NeuronesNeurones are nerve cells. They carry information as tiny electrical signals. There are  three different types of neurones, each with a slightly different function. 1. Sensory neurons  carry signals from  receptors  to the spinal cord and brain. 2. Relay neurons  carry messages from one part of the  CNS  to another. 3. Motor neurons  carry signals from the  CNS  to effectors. The diagram below shows a typical neuron – in this case, a motor neuron. It has tiny branches at each end and a long fibre carries the signals. A motor neuron S ynapses Where two neurones meet, there is a tiny gap called a synapse. Signals cross this gap using chemicals.One neurone releases the chemical into the gap. The chemical diffuses across the gap and makes the next neurone transmit an electrical signal. Reflex actions When a receptor is stimulated, it  sends a signal to the central nervous system, where the brain co-ordinates the response. But sometimes  a very quick response is needed, one that does not need the involvement of the brain. This is a reflex action. Reflex actions are rapid and happen without us thinking. For example, you would pull your hand away from a hot flame without thinking about it. The animation below allows you to step through each stage of the reflex arc.This is what happens: 1. receptor detects a stimulus – change in the environment 2. sensory neurone sends signal to relay neurone 3. motor neurone sends signal to effector 4. effector produces a response The way the iris in our eye adjusts the size of the pupil in response to bright or dim light is also a reflex action. In  bright  light: * Radial muscles of the iris relax. * Circular muscles of the iris contract. * Less light enters the eye through the contracted pupil. In  dim  light: * Radial muscles of the iris contract. * Circular muscles of the iris relax. * More light enters the eye through the dilated pupil.Defending against infection Pathogens are microorganisms – such as bacteria and viruses – that cause disease. Bacteria release toxins, and viruses damage our cells. White blood cells can ingest and destroy pathogens. They can produce antibodies to destroy pathogens, and antitoxins to neutralize toxins. In vaccination pathogens are introduced into the body in a weakened form. The process causes the body to produce enough white blood cells to protect itself against the pathogens, while not getting diseased. Antibiotics are effective against bacteria, but not against viruses. Some strains of bact eria are resistant to antibiotics.Pathogens – bacteria Pathogens are  microorganisms  that cause infectious disease. Bacteria and viruses are the main pathogens. Bacteria Bacteria are  microscopic organ-isms. They come in many shapes and sizes, but even the largest are only 10 micrometres long – 10 millionths of a metre. Bacteria are  living cells  and, in favourable conditions, can multiply rapidly. Once inside the body, they release poisons or toxins that make us feel ill. Diseases caused by bacteria include:- -food poisoning -cholera -typhoid -whooping cough -gonorrhoea – a sexually transmitted disease Pathogens – viruses Viruses are many times smaller than  bacteria.They are among the smallest organisms known and consist of a fragment of genetic material inside a protective protein coat. Viruses can only reproduce  inside host cells, and they damage the cell when they do this. A virus can get inside a cell and, once there, take over and make hundreds of thousands of copies of itself. Eventually the virus copies fill the whole host cell and burst it open. The viruses are then passed out in the bloodstream, the airways, or by other routes. Diseases caused by viruses include: * influenza – flu * colds * measles * mumps * rubella * chicken pox * AIDS White blood cellsThe body has different ways of protecting itself against  pathogens. The first defence is passive immunity. This is aimed at stopping the pathogen getting into the body in the first place. The body’s passive immunity system includes the skin,  mucus  and  cilia  in the respiratory system, acid in the stomach, and enzymes  in tears. If a pathogen still manages to get into the body, the second defence takes over. This is called  active immunity, and the white blood cells have key functions in this. Functions of the white blood cells White blood cells can: * ingest pathogens and destroy them * produce antibodies to destroy pathogen s produce antitoxins that neutralise the toxins released by pathogens In a written examination, it is easy to get carried away and waffle on about things such as invaders and battles, but stick to the point. Note that: * the pathogens are not the disease – they cause the disease * white blood cells do not eat the pathogens – they ingest them * antibodies and antitoxins are not living things – they are specialised proteins More about white blood cells There are several different types of white blood cells, each with different functions, but they can be put into two main groups: * phagocytes or macrophages lymphocytes Phagocytes Phagocytes can easily pass through blood vessel walls into the surrounding tissue and move towards  pathogens  or   toxins. They then either: * ingest and absorb the pathogens or toxins * release an enzyme to destroy them Having absorbed a pathogen, the phagocytes may also send out chemical messages that help nearby lymphocytes to id entify the type of antibody needed to neutralise them. Lymphocytes Pathogens contain certain chemicals that are foreign to the body and are called antigens. Each lymphocyte carries a specific type of antibody – a protein that has a chemical ‘fit' to a certain antigen.When a lymphocyte with the appropriate antibody meets the antigen, the lymphocyte reproduces quickly, and makes many copies of the antibody that neutralises the pathogen. Antibodies neutralise pathogens in a number of ways: * they bind to pathogens and damage or destroy them * they coat pathogens, clumping them together so that they are easily ingested by phagocytes * they bind to the pathogens and release chemical signals to attract more phagocytes Lymphocytes may also release antitoxins that stick to the appropriate toxin and stop it damaging the body. Vaccination People can be immunised against a pathogen through vaccination.Different vaccines are needed for diffe-rent  pathogens. Vaccination involves putting a small amount of an inactive form of a pathogen, or dead pathogen, into the body. Vaccines can contain: * live pathogens treated to make them harmless * harmless fragments of the pathogen * toxins  produced by pathogens * dead pathogens These all act as antigens. When injected into the body, they stimulate white blood cells to produce antibodies against the pathogen. Because the vaccine contains only a weakened or harmless version of a pathogen, the vaccinated person is not in danger of developing disease – although some people may uffer a mild reaction. If the person does get infected by the pathogen later, the required lymphocytes are able to reproduce rapidly and destroy it. Vaccines and boosters Vaccines in early childhood can give protection against many serious diseases. Sometimes more than one vaccine is given at a time, like the MMR triple vaccine against mumps, measles and rubella. Sometimes vaccine boosters are needed, because the immune response ‘m emory' weakens over time. Anti-tetanus injections may need to be repeated every ten years. Antibiotics Antibiotics are substances that kill  bacteria  or stop their growth.They do not work against  viruses: it is difficult to develop drugs that kill viruses without also damaging the body’s tissues. How some common antibiotics work antibiotic| how it works| penicillin| breaks down cell walls| erythromycin| stops protein synthesis| neomycin| stops protein synthesis| vancomycin| stops protein synthesis| ciprofloxacin| stops DNA replication| Penicillin The first antibiotic – penicillin – was discovered in 1928 by Alexander Fleming. He noticed that some bacteria he had left in a petri dish had been killed by naturally occurring penicillium mould.Since the discovery of penicillin, many other antibiotics have been discovered or developed. Most antibiotics used in medicine have been altered chemically to make them more effective and safer for humans. Resistance Ba cterial strains can develop resistance to antibiotics. This happens because of natural selection. In a large population of  bacteria, there may be some cells that are not affected by the antibiotic. These cells survive and reproduce, producing even more bacteria that are not affected by the antibiotic. MRSA is methicillin-resistant staphylococcus aureus.It is very dangerous because it is resistant to most antibiotics. It is important to avoid over-use of antibiotics, so we can slow down, or stop, the development of other strains of resistant bacteria. Cleanliness One simple way to reduce the risk of infection is to maintain personal hygiene and to keep hospitals clean. Diet and Exercise Regular exercise and a balanced diet are needed to keep the body healthy. Too little food leads to a person being underweight and prone to illness, while too much food and not enough exercise leads to a person being overweight and prone to other illnesses.Excess cholesterol increases the risk of he art disease, and excess salt causes high blood pressure and increases the risk of heart disease and stroke. Nutrients A mixture of different types of food in the correct amounts is needed to maintain health. The main food groups are: The main food groups food group| found in| required by our bodies for| | potatoes, pasta, bread, bananas, sugar and rice| A source of  energy  for other life processes. Sometimes referred to as  fibre, which is actually just one – very common – type of carbohydrate. | | cheese, butter, margarine and oils| Fats are needed to make cell membranes and to  insulate  our bodies.They also contain important fat-soluble  vitamins. | | meat, fish, eggs and cheese| Growth and repair. | | whole meal bread, fruit, vegetables and pulses| The fibre or roughage in our diet is not digested, but is important because it allows the muscles in our intestines to move food through our system by  peristalsis. | Metabolic rate A healthy diet contains all the different nutrients in the correct amounts, and provides the right amount of energy for each individual. An unbalanced diet can lead to a person becoming malnourished. They may be too thin or too fat as a result, and they may suffer from deficiency diseases.Chemical reactions Respiration is the chemical reaction that allows cells to release energy from food. The metabolic rate is the speed at which such chemical reactions take place in the body. It varies because of several factors, including: * age * gender – male or female * the proportion of muscle to fat in the body * the amount of exercise and other physical activity * genetic traits The metabolic rate increases as we exercise and stays high for a while afterwards. The right amount of food Not enough food If you don't eat enough food, you will become too thin and may suffer from health problems.These include: * irregular periods in women * reduced resistance to infection * deficiency diseases Deficiency diseases include  rickets  Ã¢â‚¬â€œ which affects proper growth of the skeleton and is caused by insufficient vitamin D – and  kwashiorkor  Ã¢â‚¬â€œ which causes a swollen abdomen and is a result of insufficient protein. Problems such as these are more likely to affect people in the developing world, where it can be more difficult to get enough food. Too much food In warm weather, or when you don't do much exercise, you do not need to eat as much food as when it is cold or when you have exerted yourself physically.If you eat too much food without taking enough exercise, you will become overweight. Very fat people are described as  obese. Overweight people may suffer from health problems, including: * diabetes  Ã¢â‚¬â€œ an illness in which the body is unable to control the amount of sugar in the blood * arthritis  Ã¢â‚¬â€œ an illness in which the joints become worn, inflamed and painful * high blood pressure * heart disease The heart The heart is an organ that needs its own supply of blood to keep it working. If the blood supply is reduced, the heart muscle will not work properly and will become weaker.A heart attack happens when part of the heart does not get any blood because of a blocked artery. Cholesterol Cholesterol is a substance found in the blood. It is made in the liver and is needed for healthy cell membranes. However, too much cholesterol in the blood increases the risk of heart disease, and of diseased arteries. Good and bad cholesterol The bloodstream transports cholesterol around the body attached to  proteins. The combination of cholesterol and protein is called  lipoprotein, and there are two types. 1. Low-density lipoproteins  Ã¢â‚¬â€œ LDLs – carry cholesterol from the liver to the cells. 2.High-density lipoproteins  Ã¢â‚¬â€œ HDLs – carry excess cholesterol back to the liver. LDLs are often called ‘bad' cholesterol because they lead to fat building up on artery walls, which causes heart disease. HDLs ar e often called ‘good’ cholesterol because they help to stop fat building up in the arteries. Improving the balance A high proportion of HDLs to LDLs is good for a healthy heart. Monounsaturated and polyunsaturated oils – as found in vegetable oils – help to reduce cholesterol levels in the blood, and also increase the proportion of HDLs compared with LDLs. Check your understanding of such oils by looking at  Vegetable oils.There are also drugs that can improve high blood pressure and high cholesterol levels. Salt Table salt is sodium chloride. Too much salt in the diet can lead to  high blood pressure, which in turn leads to an increased risk of heart disease and strokes. Salt is  found naturally in many kinds of food, but more is added by food manufacturers – and many people add even more when they are eating. Processed foods often have a high proportion of salt and fat. Salt added to food during processing accounts for about two-thirds of th e average salt intake. Adaptation Adaptations – cold climatesEvery organism has certain features or characteristics that allow it to live successfully in its  habitat. These features are called adaptations, and we say that the organism is adapted to its habitat. Organisms living in different habitats need different adaptations. The polar bear Polar bears are well adapted for survival in the Arctic. They have: * a white appearance, as camouflage from prey on the snow and ice * thick layers of fat and fur, for insulation against the cold * a small surface area to volume ratio, to minimise heat loss * a greasy coat, which sheds water after swimmingThe snowshoe hare The snowshoe hare has white fur in the winter and reddish-brown fur in the summer. This means that it is camouflaged from its  predators  for most of the year. Arctic plants The Arctic is cold and windy with very little rainfall. Plants in the Arctic often grow very close to the ground and have small leaves. Thi s helps to conserve water and to avoid damage by the wind. Adaptations – hot climates The camel Camels live in deserts that are hot and dry during the day, but cold at night. They are well adapted for survival in the desert.Camels have: * Large, flat feet  to spread their weight on the sand. * Thick fur  on the top of the body for shade, and thin fur elsewhere to allow easy heat loss. * A large surface area to volume ratio  to maximise heat loss. * The  ability to go for a long time without water  (they don't store water in their humps, but they lose very little through urination and sweating). * The ability to  tolerate body temperaturesup to 42 °C. * Slit-like nostrils and two rows of eyelashesto help keep the sand out. Desert plants Cacti are well adapted for survival in the desert. They have: * Stems that can store water. Widespread root systems that can collect water from a large area. In addition,  cacti have spines instead of leaves. These minimise the surface area and so reduce water loss by  transpiration. The spines also protect the cacti from animals that might eat them. Other adaptations Animals and plants may have specific features that adapt them to their environment. These include barbs and spines, poisons and warning colours that deter predators and herbivores. Some harmless species may even resemble a poisonous or dangerous species to increase their chances of survival. Characteristics and classificationGenetic information from one species can be transferred to another species using genetic engineering. Selective breeding, also called artificial selection, involves people taking charge of selection to produce new varieties of various species. A variety is a type of a particular species that is different in some clear way from other varieties of that species. The characteristics of a species can be used to classify the species. This is sometimes difficult to do. Genetic engineering Genetic engineering is also called gen etic modification (or  GM). It is not the same as cloning.Although cloning techniques are used in genetic engineering, the two things should not be confused. The table shows some of the differences. Cloning| Genetic engineering| Produces exact copies. | Produces a unique set of genes. | Genes copied within the same species. | Genes can be swapped across species. | Selective breeding Natural selection Species gradually evolve by a process of natural selection. The individuals in any population with the inherited features best suited to the environment in which they live are most likely to survive and reproduce. When they do, they pass on the genetic information for these features to their offspring.Over time, a species can change its appearance and may even become a new species, unable to reproduce successfully with individuals of the original species. Artificial selection Selective breeding, also called artificial selection, involves people taking charge of selection to produce ne w ‘varieties' of various species. A variety is a type of a particular species that is different in some clear way from other varieties of that species. For example, pedigree dogs come in lots of different varieties (or breeds) – they may be different colours and sizes, but they are all still dogs.Suppose you wanted a variety of cow that produced a lot of milk. This is what you could do: * choose or select the cows in your herd that produce the most milk * only let these cows reproduce * select the offspring that produce the most milk * only let these offspring reproduce * keep repeating the process of selection and breeding until you achieve your goal The key here is to identify the feature you want, and only breed from the individuals that have that feature. Here are some examples of what selective breeding can produce: * hens that lay big eggs of a particular colour cattle that produce lots of meat * tomato plants that produce lots of tomatoes * crops that are resista nt to certain plant diseases Changing the characteristics of a species The characteristics of a species can be changed by: * natural selection * selective breeding * genetic engineering. The table shows some differences between these. | Natural selection| Selective breeding| Genetic engineering| Number of generations needed for change| very many| many| one| Human intervention| not needed| needed| needed| Desired outcome known? | no| yes| yes| New species formed? | yes| no| no|Notes| This is the mechanism of change in Darwin's theory of evolution| This is how new varieties or breeds are usually produced| Genetic information can come from the same species or from a different one| In selective breeding and genetic engineering, there is a goal or desired outcome. For example, we may wish to produce a variety of cow capable of producing a lot of milk, or a bacterium capable of producing insulin. There is no goal in natural selection: although we find that particular species are well adap ted to their environments, natural selection does not ‘know' what the species should be like.Individuals that are better suited to their environment are more likely to survive to reproduce, and so pass on their characteristics to the next generation, than those that are poorly suited. Classification You will remember from your Key Stage 3 studies that species with similar characteristics are put into groups, and that this is called classification. Remind yourself of the basics of classification by looking  here. Kingdoms The first rank in this system is called a kingdom. There are five kingdoms, based upon what an organism's cells are like: 1. nimals (all multicellular animals) 2. plants (all green plants) 3. fungi (moulds, mushrooms, yeast) 4. prokaryotes (bacteria, blue-green algae) 5. protoctists (Amoeba, Paramecium) Further divisions There are several further ranks before we reach a particular species. In order, these are: * kingdom * phylum * class * order * family * ge nus * species For example,  lions  have the following classification: * kingdom – animal * phylum – vertebrate * class – mammal * order – carniverous * family – cat * genus – big cat * species – lion Difficulties with classificationIt can be  easy  to classify a species. For example, we are  Homo sapiens. Classification of species rank| classification| notes| kingdom| animals|   | phylum| chordates| animals with backbones| class| mammals| animals that are warm-blooded, have lungs and body hair, produce milk and give birth to live young| order| primates| ape-like animals| family| hominids| human-like animals| genus| homo| humans| species| sapiens| modern humans| It can also be  difficult  to classify a certain organism. For example, the single-celled organism called Euglena has some confusing characteristics.It has: * chloroplasts, like a plant * no cell wall, like an animal * a flagellum to swim with, like some bacteri a A fifth kingdom, called the protoctists, was made for organisms like Euglena. The Heart The heart requires its own constant blood supply in order to keep beating and this is delivered through the coronary arteries. Genetic and lifestyle factors can lead to the coronary arteries becoming blocked, and an increased risk of heart disease. The circulatory system Blood carries oxygen and nutrients to the body’s  cells, and waste products away from them.The circulatory system consists of: * the heart, which is the muscular pump that keeps the blood moving * the arteries, which carry blood away from the heart * the veins, which return blood to the heart * the capillaries, which are tiny blood vessels that are close to the body’s cells The diagram outlines the circu-latory system. To make things clear, oxygenated blood is shown in red, and deoxygenated blood in blue. Arteries and veins The arteries carry blood from the heart, while veins return blood to it. With both, their structure is related to their function. ArteriesBlood in the arteries is under high pressure generated by the heart. The arteries have: * thick outer walls * thick layers of muscle and elastic fibres Veins The blood in veins is under lower pressure than the blood in arteries. The veins have: * thin walls * thin layers of muscle and elastic fibres Unlike arteries, veins have one-way valves in them to keep the blood moving in the correct direction. The heart The heart is a muscular organ. It keeps beating at about 70 times per minute. You can see how it pumps the blood to the lungs and the rest of the body by studying this animation.The muscle cells in the heart need a constant supply of oxygen and nutrients, and for their waste products to be removed. So the heart requires its own blood supply in order to keep beating. Blood vessels called the  coronary arteries  supply blood to the heart muscles. If they become blocked, a  heart attack  can happen. Heart attacks A heart att ack can happen because: 1. Fatty deposits build up in the coronary arteries. 2. A blood clot can form on a fatty deposit. 3. The blood clot can block a coronary artery. 4. Some heart muscle cells do not get the oxygen and nutrients they need. 5. These cells start to die.Causes of heart disease Heart disease is not usually caused by micro-organisms. It is caused by: * genetic factors, which show as a family history of heart disease * lifestyle factors Heart disease is more common in the UK than in non-industrialised countries, and many other indust-rialised nations. This is due to lifestyle factors  including: * smoking * lack of regular exercise * stress leading to a fast heart rate * drinking a lot of alcohol * poor diet A lack of exercise and a diet that is high in salt and saturated fat cause people to: * become overweight * have high blood pressure have high levels of cholesterol in their blood These factors contribute to an increased risk of heart disease. Extra Sex hormones Changes occur at puberty because of sex hormones produced by the testes in boys, and the ovaries in girls. Some changes happen to everyone, both boys and girls, while others happen in one sex only. Here are some changes that happen to both boys and girls: * pubic hair grows * underarm hair grows Here are some changes that happen to boys only: * voice breaks – gets deeper * hair grows on face and body * body becomes more muscular * testes and penis get bigger testes start to produce sperm cells Here are some changes that happen to girls only: * hips get wider * breasts develop * ovaries start to release egg cells – periods start Fertility in humans can be controlled by the artificial use of sex hormones, including contraceptive pills and fertility drugs. Competition Different species compete to survive and breed. The size of a predator population depends on the size of the prey population, and the reverse is true as well. Mutualism benefits both species involved in the relationship, but parasitism only benefits the parasite, not the host.Habitats have limited amounts of the resources needed by living organisms. Organisms must  compete  with others in order to get enough of these resources to survive. If they are unsuccessful and cannot move to another habitat, they will die. Animals Some of the resources that animals compete for: * food * water * space Animals may also compete for mates so that they can reproduce. Plants Remember that plants make their own food using  photo-synthesis, so they do not compete for food. Here are some of the things that plants do compete for: * light * water space * mineral salts Human beings Human beings are very successful organisms. We compete with animals for food resources, and we compete with both animals and plants for space and water. The nitrogen cycle Seventy-nine per cent of the air around us is nitrogen. Living things need nitrogen to make proteins, but they cannot get it directly from the air becaus e nitrogen gas is too  unreactive  to be used to make new compounds within an organism. Plants can take up and use nitrogen when it is in a more  reactive  form – for example, in  nitrates  or  ammonium salts.Changing nitrogen into a more reactive substance is called  nitrogen fixation. Nitrogen fixation Nitrogen fixation happens in three different ways: The energy in a lightning bolt can split nitrogen molecules in the air, allowing each nitrogen atom to  react  with oxygen to form  nitrogen oxides. The rain washes these oxides to the ground, where they form  nitrates. * The Haber Process  is used by industry to produce ammonia from nitrogen. Ammonia is then used to make the fertiliser that farmers spread on the soil to feed their crops. Nitrogen-fixing bacteria found in both the soil and root nodules of leguminous plants fix nitrogen into a form that can be used by plants. When plants are eaten by animals, the nitrogen compounds are passed on. Nitr ogen compounds are returned to the soil by excretion and egestion from animals, or when plants and animals die and decay. The nitrogen compounds returned in this way are  changed back  to nitrogen gas by denitrifying bacteria which live in the soil. This  completes the cycle, so that the percentage of nitrogen in the air remains constant. The nitrogen cycle

Opposites and Paradoxes in King Lear Essay

The sequence of oppositional characters and motifs in the play bring about in the audience a sense of the corruption of principles that beset the protagonists of the play. With this sense of opposition comes a strong sense of the duality within the play seemingly centred on the Epodoclean theory of a â€Å"world governed by the contrary forces of love and hate. Though this is not unusual for a stage production, McAlindon believes that when the bond of opposites that constitutes the natural order of â€Å"revolt against limit and fly to extremes. † This can be seen in the characters foremost as the sons of Gloucester as well as the daughters of Lear are directly opposed to each other. Indeed it is in the internal nature of Lear that this is focused most powerfully as his beliefs in love and kindnesses are offset by the egocentric and chloric feelings that dwell within his heart. It is mainly from the character and fate of Lear that the true extent of the breakdown of nature can be seen as within the space of two weeks he has sunk from kingship to a world of destitution and poverty as he suffers at â€Å"th’ extreme verge† in his relationship with his family. What is most tragic in relation to Lear though is his rediscovery of Cordelia before the heart wrenching death she endures as he is thrown from the heights of grief before his heart gives way under the strain of ecstatic joy. But while the emotional converses that Lear endures are tremendously powerful they are not the only matters in opposition throughout the play. There can be seen in the various settings of the play a number of thematic oppositions, with the most apparent being the contrast between the nocturnal and gloomy castle of Gloucester as opposed to the serene Dover fields where Father and daughter are reunited, where love opposes strife. Indeed there are a great number of inversions that apply a new number of possible thoughts to the understanding of the play. Lear’s sufferings are completely opposed to the more typical tragedies of the Shakespearean era where there was a distinct separation between the suffering of the social elite and â€Å"the low and the ludicrous† in the principal of the Senecan school of thought. In King Lear though it would appear to be the Saturnalism theories that prevail as the positions of the lowest are inverted with those of the highest, as Lear takes the place of his fool in declaring the unpalatable truths of the world in his madness, adopting a sense of tragedy in the manner in which this is done. There are none more demonstrative of inversions than the antonymic nominalism that occupy the play with the most pathetic being Gloucester’s praise of Goneril and Cornwall, whereby his loyalty to the king becomes â€Å"treason† whereas Edmund’s betrayal is described as a show of â€Å"loyalty. † But more than this it is a key illustration of the wickedness of protagonist such as Goneril who condemn â€Å"harmful mildness. † This sense of paradox is prevalent mostly in the evil party where it comes to signify a moral and social inversion of a rational order of things. In contrast to this a positive paradox comes to represent a renewal through destruction and a discovery though loss, most notably seen in the increase of France’s attraction for Cordelia following her rejection by Lear as she becomes an â€Å"unprized precious maid,† becoming â€Å"most choice, forsaken† as the isolation of â€Å"forsaken† seemingly highlighting the paradox. What is more is that a sense of pathos is granted through this as Lear’s misinterpretation of each one of his daughters and his reliance of the â€Å"wolfish† Regan and Goneril, as well as Gloucester’s miscomprehension of Edmund as being a â€Å"loyal and natural boy. The twin paradoxes that appear in the discovery of madness, characterised by Lear, and the discovery of vision in blindness are the most powerful in the development dignity undertaken by Lear and to an extent Gloucester in this play. McAlindon believes that of all the paradoxes it is the fact that th e tragedy develops around an inability â€Å"to contain the worst effects of a terrible eruption in nature,† and none is more terrible than the progressive failing of family links. The typical familial bond of mutual love and affection that is the ornerstone of most families is shockingly absent in King Lear though it is desperately craved by Lear himself. McAlindon believes that this style of bond involves love and justice as well as that it â€Å"predicates a glad and spontaneous performance of offices and responsibilities. † It is therefore bewildering that Edmund would break such a bond in such an anti-familial manner, undermining civilised society in the process, and comparisons can be drawn between him and Iago in his mistreatment of Claudius in Othello. Gloucester, however, can be seen to be as equally to blame for Edmund’s waywardness as his dreadful mistreatment of him, whose breeding is only acknowledged as Gloucester â€Å"often blushed,† and seems to be a victim of tragic causality as Edmund comes to believe that he owes everything to himself. The ancient Greek writers Plato and Aristotle believe that love creates emotional awareness and allows for the creation of just law. With this in mind the manner with which Lear treats the link between him and his daughters in such a material way shatters any sense of order or responsibility in his court with the dismissal of Cordelia and Kent becoming a satire of what passes for justice in society. If Plato’s theories are developed then it would seem that the main cause for injustice is a loss of human kindness and sympathy, explaining fully Edmund’s pathological hardness as his bastardy alienates him. In the same manner in which Edmund suffers a lack of acknowledgement, so too does Lear suffer the same fate, it is only through his mistreatment on the familial ties. McAlindon believes that Lear holds a heavy â€Å"dependence of personal identity on the bond† and it is his reliance on the bond as a material tie makes him a nobody after he divulges himself from his power and estate resulting in one of the most pathetic lines â€Å"I gave you all† separated from the cruelty of Regan. The greatest dignity is then conveyed onto those around him who still perceive the bond to be a union through love, and therefore still hold the same respect for Lear despite his failure to recognise them. The importance of a character understanding the treatment of time plays an integral part in the possibility of them being seen as a tragic figure. King Lear is a tragedy characteristic of its age, a tragedy of extreme and terrible violence, as there is a sense of the untimeliness of violence and destruction that rashness and impatience bring about. Most characteristic of this flaw is Lear as his kingdom implodes through his â€Å"hideous rashness† as he signals the unleashing of pitiless violence that culminates in the utterly pathetic death of Cordelia. He is ironically guilty too of being overly patient as there is an almost comic stichomythia between him and Kent portraying his unwillingness to accept facts. A parallel can be drawn with Gloucester in this as his impatience regarding the supposed traitor Edgar is both unjust and demonstrative of the nexus between time and justice as well as injustice and haste. Calculated swiftness becomes characteristic with the actions of the evil party and can be seen by Edmunds manipulation of Gloucester under the pretence of judicial behaviour as well as that of his brother as he acts â€Å"in cunning† and its placement a the beginning of the line illuminates its two meanings. In an extreme contrast the good party align themselves with time, adopting a policy of patience that is both dignified and tragic. Edgar is keen to wait for â€Å"the mature time† whilst Kent waits for the perfect moment to reveal himself to his master, however, it is his own personal tragedy that he never finds the right moment. This can be seen as a demonstration of a true heart as this is a play that appeals profoundly to the heart as much as it does to the mind. Emblematic of a noble heart is the manner in which a protagonist empathises and treats those around them and powerful contrasts can be seen between characters and their counterparts. Indeed the most powerful of these contrasts is between the â€Å"dog-hearted daughters† of Lear and Cordelia with the scenic juxtaposition of tranquil Dover and the castles and courts of Regan and Goneril a clear demonstration of this. To be truly tragic in King Lear a character possess a good heart and this is perfectly shown by the â€Å"marble hearted sisters† as opposed to Kent’s whose own heart is pierced by Lear’s rejection of Cordelia. Alongside the good characters Lear’s heart is true in its nature, though he seems to suffer the promethean anguish, with his heart replacing the traditional liver, culminating in his death which must be presumed as being from a broken heart. Compassionate love is the supreme value in the play and as discussed above beliefs and social morals come from love and therefore the heart. Conversely though a slighted heart can produce the most devastating fury and hatred through grief as not only does the heart present the duality of nature with the possibility for disunity and anarchy but in this same manner emphasizing the importance of patience. Therefore the presence of all the aforementioned undertones and subtle themes tragedy is both made distinctly more unattainable as well as becoming much more powerful in its nature, with pathos coming to play a key role in its development.

Statement of Purpose Essay Example | Topics and Well Written Essays - 500 words - 10

Statement of Purpose - Essay Example During my childhood, I was obsessed with science specifically on electronics. I always wondered how electronic parts operate. I can tell there was something like a puzzle behind every electrical tool which led me to be passionate about engineering. As I grew up, my curiosity caused me to study more about my interests and now, I have discovered and have become aware about the aspects of scientific theories applied in the real world. One important part of my journey toward my goals started in Australia. I applied to University of Technology Sydney (UTS) where I earned a diploma in engineering and science in 2010. My schooling at UTS helped me to develop a great understanding of the foundations of engineering. As my knowledge increased, my passion in Engineering became stronger therefore I decided to complete Electrical Engineering which has always been my inclination from the start as mentioned earlier. During my undergraduate program experience at [ ], my undertakings not only helped me learn the foundations of Electrical Engineering but they also facilitated me to engage in the field of Engineering. In my core classes, I performed perfectly in most of them, bringing me to become more confident about abilities. In addition, I became independent in accomplishing magnificent progress in terms of project design. During the 2nd and 3rd years of my undergraduate program, I continuously enjoyed to put a decent effort in laboratories for long hours. This gave me the opportunity to learn more about electrical theories and apply them in the laboratory using the equipment available in the school. I have been in the Chair’s Honor Roll in spring 2012 and fall 2012 as a result of my outstanding success. Moreover, I earned a GPA above 3.0. The undergraduate curriculum introduced me to a wide array  of subjects and brought me to new thoughts and

Legal Issue Paper Research Example | Topics and Well Written Essays - 1000 words

Legal Issue - Research Paper Example There may be any number of reasons for which the parents, or the single parent, may be unable to educate their child (No Child Left Behind). The aim and purpose of NCLB is to ensure the child's education through primary and secondary schools. This aim and purpose is accomplished in case the parents are doing well together. However, social conditions now are such that there are increasing numbers of single parent managing a child or children. There are also cases where either both or one of the parents are drug addicts. In such cases, it becomes difficult for the child to study. His concentration level is low and he is disturbed. The law steps in to take charge of the child in case there is nobody else among close relatives to look after the child. After the parents, the next person closer to the child is the teacher. The teacher understands the strength and weakness of the child being entrusted with the responsibility of teaching and guiding the child. In the circumstance, it is also necessary for the teacher to keep herself abreast the laws that govern her relationship with the child. No two children are equal. And there are children who may have behavioral problems and/or problems connected to their studies. Also, there are children who live in the regular family with their parents and there are children who live in the care of foster parents. ... The teacher who is knowledgeable about the legal requirements and implications in bringing up a child has an edge over the teacher who has no knowledge about the legal necessities. Laws can be powerful tools to meet the educational needs of children in foster care. However, like any tools, if the teacher does not know how to use them, they do not provide much help. This does not imply that the teacher has to be so conversant with law that she is as good as any practicing lawyer. But it does mean that she must have enough knowledge to understand the child welfare system so that the educational need of the child is better served. The teacher must take special care to understand that children in foster care receive the same right to education as all children, understand what laws have specific provisions for children in foster care, teenage girls who become pregnant before completing high school cannot be segregated in special programs and they cannot be excluded from school entirely. Moreover, the Family Education Rights and Privacy Acts (FERPA) of 1974 provides rights to parents to inspect and review their child's education records maintained by the school, to a hearing challenging what is in the student's education record, and to not have education records released to third parties without the written consent of the parent. Most states provide for criminal sanctions for parents whose children do not attend school within the required ages. Secondly, federal laws related to education have financial incentives attached to encourage state compliance in educating the children of their state (Child Law Practice). The child and the state The role of parents or foster parents becomes secondary in the matter of educating the child. This is not to say that the role of

Consumer behavior a strategic approach Essay Example | Topics and Well Written Essays - 3500 words

Consumer behavior a strategic approach - Essay Example Opportunities The increased environmental awareness of the individuals has augmented the demand for eco friendly and organic products. Moreover, the new range of skin care products available for men has helped to boost the overall revenue of the company. This has also helped to increase the sales of the company (Spangler, 2008). Threats Though the company aims to sell eco-friendly cosmetics, the suppliers of the raw materials do not seem to adhere to the standards of eco friendliness. The biggest drawback of the company that can be a threat to its market position in future is the lack of an advertising and marketing department in the company (Muller, 2005). Companies like MAC, Make up Forever etc are now following the footsteps of The Body Shop by improving on the scale of their scope of social responsibility in business. The PESTLE analysis is given in the Appendix. The present market for the cosmetics industry is highly competitive in nature. At this juncture, the lack of proper ad vertising and marketing of the products of the Body Shop can substantially detrimental to its brand value and strength of the customers. The business of Body Shop is well known in the market for its ethical standpoint. The company strictly opposes to the testing new products on animals. But L’Oreal is blamed for this practice in the market. In 2008, the Animal Rights group have sternly warned the company to abolish such practices. As the ownership of Body Shop has been undertaken by L’Oreal since 2006 with an amount of $1.14 billion, the ethical standpoint of the company is now doubted by its stakeholders (Pitman, 2006). The fall in the disposable income of the individuals due to the soaring price levels have considerably... The key stakeholders and the target publics of the Body Shop are likely to be affected by the three main issues faced by the company. †¢Ã‚  Mergers of the company: the merger of the company would affect the existing shareholders and the employees of the organization. The shareholders would be suspicious about the performance of the company in the new merged position in the market. Rather the working culture of the organization would also change with the merger, this would affect the employees. The consumers would also doubt the ethical virtues of the company after the merger as LO real is known to not follow ethical issues in business. †¢Ã‚  The recession in the world economy: the crisis of finance in the global economies can force the company cut down some jobs, this would affect the employees. Rather the fall in the disposable income levels would hamper the purchasing power capabilities of the consumers. The suppliers would also be reluctant to provide raw materials at lo wer prices. †¢Ã‚  The ethical virtues of other cosmetics companies: this would directly affect the decisions of the consumers in the market. They might reduce the demand for the products of The Body Shop. Considering the initial business analysis, it can be stated that any change made in the business operations of The Body Shop would surely affect its stakeholders. Figure 1 and 2 in the Appendix, shows the stakeholders map for the Body. The most important stakeholders of the company are the customers and the shareholders.

Victoria's secret enters Argentina ( Retail marketing plan) Assignment

Victoria's secret enters Argentina ( Retail marketing plan) - Assignment Example The current marketing strategy of the company has a very high reliance on the latest trends in advertising such as Facebook and the internet. The marketing objective is to develop a positive growth of over 15% in the coming two years. The segmentation, targeting and positioning of the company has been labelled as targeting the female population in the Argentine market, position itself in the right segment (geographical) and attract the entire female population to its products. The entry strategy will be through exports at the initial levels and then use mergers and acquisitions as well as franchising to develop faster into the new market. With both internal and external controls, the company hopes for a successful venture into the Argentine market. Retail marketing strategy refer to expansion of already established retail stores, the goods therein and the relationship that is created with the customers (Ferrell & Hartline, 2012, p. 34). All these established stores must make decisions about their details in the market as well as the marketing mix to concentrate on. A business strategy must therefore put in consideration all the factors that must be considered before a market is considered for supply as a retail store. Large retail stores may choose to venture into the international markets by virtue of expanding their sales. Victorias secret is the largest company in America specialising in making ladies’ lingerie. Founded in 1977, the company makes women’s’ wear and has progressed to an extent of planning to venture into new markets it has never operated in. This report seeks to establish a retail marketing plan of Victorias Secret Company in its bid to venture into the Argentine market. In view of this, it will make an analysis of the Argentina market structures with special focus on the culture of the country given that the company operates in the cloth line retail industry. A situational analysis will be carried out to

Foreign Exchange Risk Essay Example | Topics and Well Written Essays - 1500 words - 1

Foreign Exchange Risk - Essay Example Exporting and importing also implies considerable foreign exchange risks for the companies involved. Importers will have to pay a higher price if their home currency depreciates against the exporting foreign country and vice versa. International retailing operations also entail high exposure to foreign exchange risk as the exchange rate of any of the two countries fluctuates. The fluctuations in exchange rate â€Å"†¦result in direct changes in the relative prices of domestic and foreign goods†¦Ã¢â‚¬  (Bartov and Bodnar, 1994, p. 1758) It ultimately increases the exposure of virtually all forms of international operations to foreign exchange risk. Foreign exchange or currency risk affects a company in several different ways viz. sales level, future cash flows, financial reporting, product price and production etc. Bartov and Bodnar propound that exchange rate fluctuations â€Å"†¦influence both the current and future expected cash flows of firms with international operations.† (1994, p. 1758). Fluctuation in exchange rate can affect a company’s future cash flows by increasing or decreasing the price of goods and services in the domestic or foreign country. It can also affect a company’s operational performance by increasing or decreasing the cost of importing raw material. Currency rates have a significant impact on the reporting of sales level. If the foreign exchange rates are favourable, the company’s reported sales will rise (Bartov and Bodnar, 1994). Therefore, apart from affecting its real future cash flows, exchange rate fluctuations bear the capacity to influence its reported revenues. Exposure to foreign exchange risk can also affect a company’s production level and its prices. It will be costlier for companies to import products from a foreign country having a high exchange rate as compared to the domestic

Journal about Religion Assignment Example | Topics and Well Written Essays - 250 words

Journal about Religion - Assignment Example These religions contribute to creation and maintenance of peace among people. They also help to instil and shape the moral aspects of human beings by teaching people how to behave in the society. People can identify what is bad and good or wrong and right through religious teachings. For instance, through religious teachings, a child grows up knowing that stealing is wrong and helping others is right. Therefore, the religion helps to shape up the behaviors of people by promoting morality and righteousness in life (Haight 123). Most of the religions in the world support peace. However, wars and violence historically and presently seem to transpire in the name of religion. Most armed conflicts and wars are undertaken for religious reasons. Religious components contribute either directly or indirectly to armed as well as inter-ethnic conflicts. For instance, Muslims and Christians have lived their life-fighting due to religious differences. Some Muslims fanatics, particularly in the country of Somalia, execute Christians unnecessarily (Williams

Why White Collar Crimes are Committed Essay Example | Topics and Well Written Essays - 500 words

Why White Collar Crimes are Committed - Essay Example By implementing the theory of Individualism in criminology, certain factors that lead to the causation of this form of white collar crime become evident. According to Sutherland (1994), personality and individual characteristics are not sufficient to offer a full comprehensive example of white collar crime. However, these two characteristics should not be dismissed entirely nor should the theory of the individualistic level (Friedrich 2004). The reason this is stated is due to the implied idea that top corporate professionals, within these aforementioned companies are interpreted to the general public as being greedy and self preserving. This is obvious by the fact that if ethic's and concern for other investors had been deciding factors, these criminal actions of fraud and embezzlement (among others) would have never taken place. Many times the individualistic theory in white collar crime points to greed as the main causation for the crime or crimes. What it amounts to is the fact that these executives would rather take the wrong highway to achieve higher positions of importance and financial flare/success than worry about what repercussions for their actions might be later down the road (Friedrich 2004).

Cross cultural Coursework Example | Topics and Well Written Essays - 1500 words

Cross cultural - Coursework Example In this empirical research, the leadership style of Indian, UK and US managers have been compared. The basic theory used in this research is Hofstede theory of culture. As the leadership styles are influenced by cultures of different nations, it is important to understand the basic culture of the nation. Thus, Hofstede’s cultural dimensions theory will help in evaluating strategies which leaders need to apply while working in different nations (Hofstede, 2007). Leadership styles Leadership styles across the globe are diverse and influenced by specific attributes dominating the environment. Various leadership styles have been researched and identifies by scholars. These include; 1. Autocratic Leadership It is described as an extreme transactional leadership style. The leader exerts a lot of power over individuals. There is a little opportunity for staffs and team members in terms of making suggestions or decisions. The style is best used during crisis situation. 2. Bureaucratic Leadership In bureaucratic style, rules are followed vigorously and the major objective of the leader is to make sure that every team member follows the guidelines and procedures. This style of leadership will work best on organisations having routine tasks such as factories and manufacturing units. 3. Charismatic Leadership It is a type of transformational leadership. ... Leadership studies Leadership can be defined as an individual’s ability to influence and inspire the attitude, behaviour and thinking of other individuals. The principle objective of a leader is to assure that synergy is achieved in the organisation where the leader works. A leader is expected to bring mutual understanding and coordination in the workplace through joint efforts from the employees working in the organisation (Dowling, Welch and Schuler, 1999). Researches from various studies conducted all over the world have suggested that leadership styles vary from nation to nation and even from region to region. In some nations leadership means authority, control and power (Fatehi, 1996). While in other nations it may signify motivating employees and subordinates, in a manner which is non-coercive. Thus, it is becoming increasingly important for leaders to understand the culture and perception of people/employees, where the company has established its subsidiary (Aycan, et a l., 2000). Countries and leadership styles USA Most of the US leaders tend to use participative, charismatic or directive leadership styles. Freedom of action is less for board of directors and executives in America. There is no congruent culture and the general tendencies include dominance, individualism and functionalism. UK Individualistic, informative and descriptive leadership styles are followed by managers in UK. They have a particular affinity to details and in-depth analysis. They are more willing to take decisions on individual basis and also delegate responsibilities and tasks to others. Comparison of the US, UK and Indian leadership Styles In order to compare leadership styles of America and India, Hofstede Cultural model have been used. 1.

Minority Group and Multiculturalism Essay Example for Free

Minority Group and Multiculturalism Essay Ideas about the legal and political accommodation of ethnic diversity — commonly termed â€Å"multiculturalism† — emerged in the West as a vehicle for replacing older forms of ethnic and racial hierarchy with new relations of democratic citizenship. Despite substantial evidence that these policies are making progress toward that goal, a chorus of political leaders has declared them a failure and heralded the death of multiculturalism. This popular master narrative is problematic because it mischaracterizes the nature of the experiments in multiculturalism that have been undertaken, exaggerates the extent to which they have been abandoned, and misidentifies not only the genuine difficulties and limitations they have encountered but the options for addressing these problems. Talk about the retreat from multiculturalism has obscured the fact that a form of multicultural integration remains a live option for Western democracies. This report challenges four powerful myths about multiculturalism. First, it disputes the caricature of multiculturalism as the uncritical celebration of diversity at the expense of addressing grave societal problems such as unemployment and social isolation. Instead it offers an account of multiculturalism as the pursuit of new relations of democratic citizenship, inspired and constrained by human-rights ideals. Second, it contests the idea that multiculturalism has been in wholesale retreat, and offers instead evidence that multiculturalism policies (MCPs) have persisted, and have even grown stronger, over the past ten years. Third, it challenges the idea that multiculturalism has failed, and offers instead evidence that MCPs have had positive effects. Fourth, it disputes the idea that the spread of civic integration policies has displaced multiculturalism or rendered it obsolete. The report instead offers evidence that MCPs are fully consistent with certain forms of civic integration policies, and that indeed the combination of multiculturalism with an â€Å"enabling† form of civic integration is both normatively desirable and empirically effective in at least some cases. To help address these issues, this paper draws upon the Multiculturalism Policy Index. This index 1) identifies eight concrete policy areas where liberal-democratic states — faced with a choice — decided to develop more multicultural forms of citizenship in relation to immigrant groups and 2) measures the extent to which countries have espoused some or all of these policies over time. While there have been some high-profile cases of retreat from MCPs, such as the Netherlands, the general pattern from 1980 to 2010 has been one of modest strengthening. Ironically, some countries that have been vociferous about multiculturalism’s â€Å"failure† (e. g. , Germany) have not actually practiced an active multicultural strategy. Talk about the retreat from multiculturalism has obscured the fact that a form of multicultural integration remains a live option for Western democracies. However, not all attempts to adopt new models of multicultural citizenship have taken root or succeeded in achieving their intended effects. There are several factors that can either facilitate or impede the successful implementation of multiculturalism: Multiculturalism: Success, Failure, and the Future 1 MIGRATION POLICY INSTITUTE Desecuritization of ethnic relations. Multiculturalism works best if relations between the state and minorities are seen as an issue of social policy, not as an issue of state security. If the state perceives immigrants to be a security threat (such as Arabs and Muslims after 9/11), support for multiculturalism will drop and the space for minorities to even voice multicultural claims will diminish. Human rights. Support for multiculturalism rests on the assumption that there is a shared commitment to human rights across ethnic and religious lines. If states perceive certain groups as unable or unwilling to respect human-rights norms, they are unlikely to accord them multicultural rights or resources. Much of the backlash against multiculturalism is fundamentally driven by anxieties about Muslims, in particular, and their perceived unwillingness to embrace liberal-democratic norms. Border control. Multiculturalism is more controversial when citizens fear they lack control over their borders — for instance when countries are faced with large numbers (or unexpected surges) of unauthorized immigrants or asylum seekers — than when citizens feel the borders are secure. Diversity of immigrant groups. Multiculturalism works best when it is genuinely multicultural — that is, when immigrants come from many source countries rather than coming overwhelmingly from just one (which is more likely to lead to polarized relations with the majority). Economic contributions. Support for multiculturalism depends on the perception that immigrants are holding up their end of the bargain and making a good-faith effort to contribute to society — particularly economically. When these facilitating conditions are present, multiculturalism can be seen as a low-risk option, and indeed seems to have worked well in such cases. Multiculturalism tends to lose support in high-risk situations where immigrants are seen as predominantly illegal, as potential carriers of illiberal practices or movements, or as net burdens on the welfare state. However, one could argue that rejecting immigrant multiculturalism under these circumstances is in fact the higher-risk move. It is precisely when immigrants are perceived as illegitimate, illiberal, and burdensome that multiculturalism may be most needed. I. Introduction Ideas about the legal and political accommodation of ethnic diversity have been in a state of flux around the world for the past 40 years. One hears much about the â€Å"rise and fall of multiculturalism. † Indeed, this has become a kind of master narrative, widely invoked by scholars, journalists, and policymakers alike to explain the evolution of contemporary debates about diversity. Although people disagree about what comes after multiculturalism, there is a surprising consensus that we are in a post-multicultural era. This report contends that this master narrative obscures as much as it reveals, and that we need an alternative framework for thinking about the choices we face. Multiculturalism’s successes and failures, as well as its level of public acceptance, have depended on the nature of the issues at stake and the countries involved, and we need to understand these variations if we are to identify a more sustainable model for accommodating diversity. This paper will argue that the master narrative 1) mischaracterizes the nature of the experiments in multiculturalism that have been undertaken, 2) exaggerates the extent to which they have been abandoned, and 3) misidentifies the genuine difficulties and limitations they have encountered and the options for addressing these problems. 2 Multiculturalism: Success, Failure, and the Future MIGRATION POLICY INSTITUTE Before we can decide whether to celebrate or lament the fall of multiculturalism, we need first to make sure we know what multiculturalism has meant both in theory and in practice, where it has succeeded or failed to meet its objectives, and under what conditions it is likely to thrive in the future. The Rise and Fall of Multiculturalism The master narrative of the â€Å"rise and fall of multiculturalism† helpfully captures important features of our current debates. Yet in some respects it is misleading, and may obscure the real challenges and opportunities we face. In its simplest form, the master narrative goes like this:1 Since the mid-1990s we have seen a backlash and retreat from multiculturalism. From the 1970s to mid-1990s, there was a clear trend across Western democracies toward the increased recognition and accommodation of diversity through a range of multiculturalism policies (MCPs) and minority rights. These policies were endorsed both at the domestic level in some states and by international organizations, and involved a rejection of earlier ideas of unitary and homogeneous nationhood. Since the mid-1990s, however, we have seen a backlash and retreat from multiculturalism, and a reassertion of ideas of nation building, common values and identity, and unitary citizenship — even a call for the â€Å"return of assimilation. † This retreat is partly driven by fears among the majority group that the accommodation of diversity has â€Å"gone too far† and is threatening their way of life. This fear often expresses itself in the rise of nativist and populist right-wing political movements, such as the Danish People’s Party, defending old ideas of â€Å"Denmark for the Danish. † But the retreat also reflects a belief among the center-left that multiculturalism has failed to help the intended beneficiaries — namely, minorities themselves — because it has failed to address the underlying sources of their social, economic, and political exclusion and may have unintentionally contributed to their social isolation. As a result, even the center-left political movements that initially championed multiculturalism, such as the social democratic parties in Europe, have backed 1 For influential academic statements of this â€Å"rise and fall† narrative, claiming that it applies across the Western democracies, see Rogers Brubaker, â€Å"The Return of Assimilation? † Ethnic and Racial Studies 24, no. 4 (2001): 531–48; and Christian Joppke, â€Å"The Retreat of Multiculturalism in the Liberal State: Theory and Policy,† British Journal of Sociology 55, no. 2 (2004): 237–57. There are also many accounts of the â€Å"decline,† â€Å"retreat,† or â€Å"crisis† of multiculturalism in particular countries. For the Netherlands, see Han Entzinger, â€Å"The Rise and Fall of Multiculturalism in the Netherlands,† in Toward Assimilation and Citizenship: Immigrants in Liberal Nation-States, eds. Christian Joppke and Ewa Morawska (London: Palgrave, 2003) and Ruud Koopmans, â€Å"Trade-Offs between Equality and Difference: The Crisis of Dutch Multiculturalism in Cross-National Perspective† (Brief, Danish Institute for International Studies, Copenhagen, December 2006). For Britain, see Randall Hansen, â€Å"Diversity, Integration and the Turn from Multiculturalism in the United Kingdom,† in Belonging? Diversity, Recognition and Shared Citizenship in Canada, eds. Keith G. Banting, Thomas J. Courchene, and F. Leslie Seidle (Montreal: Institute for Research on Public Policy, 2007); Les Back, Michael Keith, Azra Khan, Kalbir Shukra, and John Solomos, â€Å"New Labour’s White Heart: Politics, Multiculturalism and the Return of Assimilation,† Political Quarterly 73, No. 4 (2002): 445–54; Steven Vertovec, â€Å"Towards post-multiculturalism? Changing communities, conditions and contexts of diversity,† International Social Science Journal 61 (2010): 83–95. For Australia, see Ien Ang and John Stratton, â€Å"Multiculturalism in Crisis: The New Politics of Race and National Identity in Australia,† in On Not Speaking Chinese: Living Between Asia and the West, ed. I. Ang (London: Routledge, 2001). For Canada, see Lloyd Wong, Joseph Garcea, and Anna Kirova, An Analysis of the ‘Anti- and Post-Multiculturalism’ Discourses: The Fragmentation Position (Alberta: Prairie Centre for Excellence in Research on Immigration and Integration, 2005), http://pmc.metropolis. Net/Virtual%20Library/FinalReports/Post-multi%20FINAL%20REPORT%20for%20PCERII%20_2_. pdf. For a good overview of the backlash discourse in various countries, see Steven Vertovec and Susan Wessendorf, eds. , The Multiculturalism Backlash: European Discourses, Policies and Practices (London: Routledge, 2010). Multiculturalism: Success, Failure, and the Future 3 MIGRATION POLICY INSTITUTE away from it and shifted to a discourse that emphasizes â€Å"civic integration,† â€Å"social cohesion,† â€Å"common values,† and â€Å"shared citizenship. †2 The social-democratic discourse of civic integration differs from the radical-right discourse in emphasizing the need to develop a more inclusive national identity and to fight racism and discrimination, but it nonetheless distances itself from the rhetoric and policies of multiculturalism. The term postmulticulturalism has often been invoked to signal this new approach, which seeks to overcome the limits of a naive or misguided multiculturalism while avoiding the oppressive reassertion of homogenizing nationalist ideologies. 3 II. What Is Multiculturalism? A. Misleading Model In much of the post-multiculturalist literature, multiculturalism is characterized as a feel-good celebration of ethnocultural diversity, encouraging citizens to acknowledge and embrace the panoply of customs, traditions, music, and cuisine that exist in a multiethnic society. Yasmin Alibhai-Brown calls this the â€Å"3S† model of multiculturalism in Britain — saris, samosas, and steeldrums. 4. Multiculturalism takes these familiar cultural markers of ethnic groups — clothing, cuisine, and music — and treats them as authentic practices to be preserved by their members and safely consumed by others. Under the banner of multiculturalism they are taught in school, performed in festivals, displayed in media and museums, and so on. This celebratory model of multiculturalism has been the focus of many critiques, including the following: It ignores issues of economic and political inequality. Even if all Britons come to enjoy Jamaican steeldrum music or Indian samosas, this would do nothing to address the real problems facing Caribbean and South Asian communities in Britain — problems of unemployment, poor educational outcomes, residential segregation, poor English language skills, and political marginalization. These economic and political issues cannot be solved simply by celebrating cultural differences. Even with respect to the (legitimate) goal of promoting greater understanding of cultural differences, the focus on celebrating â€Å"authentic† cultural practices that are â€Å"unique† to each group is potentially dangerous. First, not all customs that may be traditionally practiced within a particular group are worthy of being celebrated, or even of being legally tolerated, such as forced marriage. To avoid stirring up controversy, there’s a tendency to choose as the focus of multicultural celebrations safely inoffensive practices — such as cuisine or music — that can be enjoyably consumed by members of the larger society. But this runs the opposite risk 2. For an overview of the attitudes of European social democratic parties to these issues, see Rene Cuperus, Karl Duffek, and Johannes Kandel, eds. , The Challenge of Diversity: European Social Democracy Facing Migration, Integration and Multiculturalism (Innsbruck: Studien Verlag, 2003). For references to â€Å"post-multiculturalism† by progressive intellectuals, who distinguish it from the radical right’s â€Å"antimulticulturalism,† see, regarding the United Kingdom, Yasmin Alibhai-Brown, After Multiculturalism (London: Foreign Policy Centre, 2000), and â€Å"Beyond Multiculturalism,† Canadian Diversity/Diversite Canadienne 3, no. 2 (2004): 51–4; regarding Australia, James Jupp, From White Australia to Woomera: The Story of Australian Immigration, 2nd edition (Cambridge: Cambridge University Press, 2007); and regarding the United States, Desmond King, The Liberty of Strangers: Making the American Nation (Oxford: Oxford University Press, 2004), and David A. Hollinger, Post-ethnic America: Beyond Multiculturalism, revised edition (New York: Basic Books, 2006). Alibhai-Brown, After Multiculturalism. 3 4 4 Multiculturalism: Success, Failure, and the Future MIGRATION POLICY INSTITUTE of the trivialization or Disneyfication of cultural differences,5 ignoring the real challenges that differences in cultural and religious values can raise. Third, the 3S model of multiculturalism can encourage a conception of groups as hermetically sealed and static, each reproducing its own distinct practices. Multiculturalism may be intended to encourage people to share their customs, but the assumption that each group has its own distinctive customs ignores processes of cultural adaptation, mixing, and melange, as well as emerging cultural commonalities, thereby potentially reinforcing perceptions of minorities as eternally â€Å"other. † This in turn can lead to the strengthening of prejudice and stereotyping, and more generally to the polarization of ethnic relations. Fourth, this model can end up reinforcing power inequalities and cultural restrictions within minority groups. In deciding which traditions are â€Å"authentic,† and how to interpret and display them, the state generally consults the traditional elites within the group — typically older males — while ignoring the way these traditional practices (and traditional elites) are often challenged by internal reformers, who have different views about how, say, a â€Å"good Muslim† should act. It can therefore imprison people in â€Å"cultural scripts† that they are not allowed to question or dispute. According to post-multiculturalists, the growing recognition of these flaws underlies the retreat from multiculturalism and signals the search for new models of citizenship that emphasize 1) political participation and economic opportunities over the symbolic politics of cultural recognition, 2) human rights and individual freedom over respect for cultural traditions, 3) the building of inclusive national identities over the recognition of ancestral cultural identities, and 4) cultural change and cultural mixing over the reification of static cultural differences. This narrative about the rise and fall of 3S multiculturalism will no doubt be familiar to many readers. In my view, however, it is inaccurate. Not only is it a caricature of the reality of multiculturalism as it has developed over the past 40 years in the Western democracies, but it is a distraction from the real issues that we need to face. The 3S model captures something important about natural human tendencies to simplify ethnic differences, and about the logic of global capitalism to sell cosmopolitan cultural products, but it does not capture the nature of post-1960s government MCPs, which have had more complex historical sources and political goals. B. Multiculturalism in Context It is important to put multiculturalism in its historical context. In one sense, it is as old as humanity — different cultures have always found ways of coexisting, and respect for diversity was a familiar feature of many historic empires, such as the Ottoman Empire. But the sort of multiculturalism that is said to have had a â€Å"rise and fall† is a more specific historic phenomenon, emerging first in the Western democracies in the late 1960s. This timing is important, for it helps us situate multiculturalism in relation to larger social transformations of the postwar era. More specifically, multiculturalism is part of a larger human-rights revolution involving ethnic and racial diversity. Prior to World War II, ethnocultural and religious diversity in the West was characterized by a range of illiberal and undemocratic relationships of hierarchy,6 justified by racialist ideologies that explicitly propounded the superiority of some peoples and cultures and their right to rule over others. These ideologies were widely accepted throughout the Western world and underpinned both domestic laws (e. g. , racially biased immigration and citizenship policies) and foreign policies (e. g. , in relation to overseas colonies). 5 6 Neil Bissoondath, Selling Illusions: The Cult of Multiculturalism in Canada. (Toronto: Penguin, 1994). Including relations of conqueror and conquered, colonizer and colonized, master and slave, settler and indigenous, racialized and unmarked, normalized and deviant, orthodox and heretic, civilized and primitive, and ally and enemy. Multiculturalism: Success, Failure, and the Future 5 MIGRATION POLICY INSTITUTE After World War II, however, the world recoiled against Hitler’s fanatical and murderous use of such ideologies, and the United Nations decisively repudiated them in favor of a new ideology of the equality of races and peoples. And this new assumption of human equality generated a series of political movements designed to contest the lingering presence or enduring effects of older hierarchies. We can distinguish three â€Å"waves† of such movements: 1) the struggle for decolonization, concentrated in the period 1948–65; 2) the struggle against racial segregation and discrimination, initiated and exemplified by the AfricanAmerican civil-rights movement from 1955 to 1965; and 3) the struggle for multiculturalism and minority rights, which emerged in the late 1960s. Multiculturalism is part of a larger human-rights revolution involving ethnic and racial diversity. Each of these movements draws upon the human-rights revolution, and its foundational ideology of the equality of races and peoples, to challenge the legacies of earlier ethnic and racial hierarchies. Indeed, the human-rights revolution plays a double role here, not just as the inspiration for a struggle, but also as a constraint on the permissible goals and means of that struggle. Insofar as historically excluded or stigmatized groups struggle against earlier hierarchies in the name of equality, they too have to renounce their own traditions of exclusion or oppression in the treatment of, say, women, gays, people of mixed race, religious dissenters, and so on. Human rights, and liberal-democratic constitutionalism more generally, provide the overarching framework within which these struggles are debated and addressed. Each of these movements, therefore, can be seen as contributing to a process of democratic â€Å"citizenization† — that is, turning the earlier catalog of hierarchical relations into relationships of liberaldemocratic citizenship. This entails transforming both the vertical relationships between minorities and the state and the horizontal relationships among the members of different groups. In the past, it was often assumed that the only way to engage in this process of citizenization was to impose a single undifferentiated model of citizenship on all individuals. But the ideas and policies of multiculturalism that emerged from the 1960s start from the assumption that this complex history inevitably and appropriately generates group-differentiated ethnopolitical claims. The key to citizenization is not to suppress these differential claims but to filter them through and frame them within the language of human rights, civil liberties, and democratic accountability. And this is what multiculturalist movements have aimed to do. The precise character of the resulting multicultural reforms varies from group to group, as befits the distinctive history that each has faced. They all start from the antidiscrimination principle that underpinned the second wave but go beyond it to challenge other forms of exclusion or stigmatization. In most Western countries, explicit state-sponsored discrimination against ethnic, racial, or religious minorities had largely ceased by the 1960s and 1970s, under the influence of the second wave of humanrights struggles. Yet ethnic and racial hierarchies persist in many societies, whether measured in terms of economic inequalities, political underrepresentation, social stigmatization, or cultural invisibility. Various forms of multiculturalism have been developed to help overcome these lingering inequalities. The focus in this report is on multiculturalism as it pertains to (permanently settled) immigrant groups,7 7 There was briefly in some European countries a form of â€Å"multiculturalism† that was not aimed at the inclusion of permanent immigrants, but rather at ensuring that temporary migrants would return to their country of origin. For example, mothertongue education in Germany was not initially introduced â€Å"as a minority right but in order to enable guest worker children to reintegrate in their countries of origin† (Karen Schonwalder, â€Å"Germany: Integration Policy and Pluralism in a Self-Conscious Country of Immigration,† in The Multiculturalism Backlash: European Discourses, Policies and Practices, eds. Steven Vertovec and Susanne Wessendorf [London: Routledge, 2010], 160). Needless to say, this sort of â€Å"returnist† multiculturalism — premised on the idea that migrants are foreigners who should return to their real home — has nothing to do with multiculturalism policies (MCPs) premised on the idea that immigrants belong in their host countries, and which aim to make immigrants 6 Multiculturalism: Success, Failure, and the Future MIGRATION POLICY INSTITUTE but it is worth noting that struggles for multicultural citizenship have also emerged in relation to historic minorities and indigenous peoples. 8 C. The Evolution of Multiculturalism Policies. The case of immigrant multiculturalism is just one aspect of a larger â€Å"ethnic revival† across the Western democracies,9 in which different types of minorities have struggled for new forms of multicultural citizenship that combine both antidiscrimination measures and positive forms of recognition and accommodation. Multicultural citizenship for immigrant groups clearly does not involve the same types of claims as for indigenous peoples or national minorities: immigrant groups do not typically seek land rights, territorial autonomy, or official language status. What then is the substance of multicultural citizenship in relation to immigrant groups? The Multiculturalism Policy Index is one attempt to measure the evolution of MCPs in a standardized format that enables comparative research. 10 The index takes the following eight policies as the most common or emblematic forms of immigrant MCPs:11 Constitutional, legislative, or parliamentary affirmation of multiculturalism, at the central and/ or regional and municipal levels The adoption of multiculturalism in school curricula The inclusion of ethnic representation/sensitivity in the mandate of public media or media licensing Exemptions from dress codes, either by statute or by court cases Allowing of dual citizenship The funding of ethnic group organizations to support cultural activities The funding of bilingual education or mother-tongue instruction Affirmative action for disadvantaged immigrant groups12 feel more at home where they are. The focus of this paper is on the latter type of multiculturalism, which is centrally concerned with constructing new relations of citizenship. 8 In relation to indigenous peoples, for example — such as the Maori in New Zealand, Aboriginal peoples in Canada and Australia, American Indians, the Sami in Scandinavia, and the Inuit of Greenland — new models of multicultural citizenship have emerged since the late 1960s that include policies such as land rights, self-government rights, recognition of customary laws, and guarantees of political consultation. And in relation to substate national groups — such as the Basques and Catalans in Spain, Flemish and Walloons in Belgium, Scots and Welsh in Britain, Quebecois in Canada, Germans in South Tyrol, Swedish in Finland — we see new models of multicultural citizenship that include policies such as federal or quasi-federal territorial autonomy; official language status, either in the region or nationally; and guarantees of representation in the central government or on constitutional courts. 9. Anthony Smith, The Ethnic Revival in the Modern World (Cambridge: Cambridge University Press, 1981). 10 Keith Banting and I developed this index, first published in Keith Banting and Will Kymlicka, eds. , Multiculturalism and the Welfare State: Recognition and Redistribution in Contemporary Democracies (Oxford: Oxford University Press, 2006). Many of the ideas discussed in this paper are the result of our collaboration. 11 As with all cross-national indices, there is a trade-off between standardization and sensitivity to local nuances. There is no universally accepted definition of multiculturalism policies and no hard and fast line that would sharply distinguish MCPs from closely related policy fields, such as antidiscrimination policies, citizenship policies, and integration policies. Different countries (or indeed different actors within a single country) are likely to draw this line in different places, and any list is therefore likely to be controversial. 12 For a fuller description of these policies, and the justification for including them in the Multiculturalism Policy Index, see the index website, www.queensu. ca/mcp. The site also includes our separate index of MCPs for indigenous peoples and for national minorities. Multiculturalism: Success, Failure, and the Future 7 MIGRATION POLICY INSTITUTE Other policies could be added (or subtracted) from the index, but there was a recognizable â€Å"multiculturalist turn† across Western democracies in the last few decades of the 20th century, and we can identify a range of public policies that are seen, by both critics and defenders, as emblematic of this turn. Each of the eight policy indicators listed above is intended to capture a policy dimension where liberaldemocratic states faced a choice about whether or not to take a multicultural turn and to develop more multicultural forms of citizenship in relation to immigrant groups. While multiculturalism for immigrant groups clearly differs in substance from that for indigenous peoples or national minorities, each policy has been defended as a means to overcome the legacies of earlier hierarchies and to help build fairer and more inclusive democratic societies. Therefore, multiculturalism is first and foremost about developing new models of democratic citizenship, grounded in human-rights ideals, to replace earlier uncivil and undemocratic relations of hierarchy and exclusion. Needless to say, this account of multiculturalism-as-citizenization differs dramatically from the 3S account of multiculturalism as the celebration of static cultural differences. Whereas the 3S account says that multiculturalism is about displaying and consuming differences in cuisine, clothing, and music, while neglecting issues of political and economic inequality, the citizenization account says that multiculturalism is precisely about constructing new civic and political relations to overcome the deeply entrenched inequalities that have persisted after the abolition of formal discrimination. It is important to determine which of these accounts more accurately describes the Western experience with multiculturalism. Before we can decide whether to celebrate or lament the fall of multiculturalism, we first need to make sure we know what multiculturalism has in fact been. The 3S account is misleading for three principal reasons. 13 Multiculturalism is first and foremost about developing new models of democratic citizenship, grounded in human-rights ideals. First, the claim that multiculturalism is solely or primarily about symbolic cultural politics depends on a misreading of the actual policies. Whether we look at indigenous peoples, national minorities, or immigrant groups, it is immediately apparent that MCPs combine economic, political, social, and cultural dimensions. While minorities are (rightly) concerned to contest the historic stigmatization of their cultures, immigrant multiculturalism also includes policies that are concerned with access to political power and economic opportunities — for example, policies of affirmative action, mechanisms of political consultation, funding for ethnic self-organization, and facilitated access to citizenship. In relation all three types of groups, MCPs combine cultural recognition, economic redistribution, and political participation. Second, the claim that multiculturalism ignores the importance of universal human rights is equally misplaced. On the contrary, as we’ve seen, multiculturalism is itself a human-rights-based movement, inspired and constrained by principles of human rights and liberal-democratic constitutionalism. Its goal is to challenge the traditional ethnic and racial hierarchies that have been discredited by the postwar human-rights revolution. Understood in this way, multiculturalism-as-citizenization offers no support for accommodating the illiberal cultural practices within minority groups that have also The same human-righ.