B1 UNDERSTANDING ORGANISMS

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Fitness & Health

fitness level, measuring, stamina, strength, flexibility, agility, speed, cardiovascular efficiency

good health is being free from disease

heart disease: increased if high BP, smoke, to much saturdated fat, to much salt

BP: muscle contracts each time heart beats, contracts: systolic, relax: diastolic, systolic increases when exercising

high BP: causes, smoking, alcohol, salt, overweight, stress, saturdated fat, more likely to have heart attack, stroke, suffer from kidney damage.

smoking can increase BP by carbon monoxide combines with haemoglobin in the red cells (carry less oxygeon) nicotine increases heart rate

thrombosis and saturated fat: blood clot deposited in the artery walls restrics the blood flow.

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Health & Diet

right amount of different foods carbs: energy: stored in the liver: fat: energy:  stored under skin: proteins: growth and repair: iron heamoglobin: vitamin C: prevent scurvy: fibre: prevent constipation: wateer: prevent dehidration replace lost water. may change according to age, gender, religion, medical reasons, personal choice

ear always an average. EAR in grams= 0.6 x body mass in Kg

if you dont eat enough protien as a child you will develop Kwashiorkor, a disiese mostly found in under developed contries this can lead to children being malnourished and they contract the disease, and their belly swells but their arms are extremely skinny

BMI: mass / height in meters. underweight= under 18kg/m . normal= 18-25. overweight= 20-30 obese= over 30. possible health risks with being over weight are heart disease, arthritis, diabetes, breast cancer.

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Preventing Disease

caused by microorganisms (parasites). vitamin deficiency: scurvey. mineral difficiency: anaemia. body disorder: diabetes, cancer. genetic inheritance: red-green colour blindness

the risks of cancer can be reduced by, sunbathing little, avoid eating fat, avoid eating red meat and processed food, eat plenty of fresh foods, do regular exercise, drink little alcohol.

tumours:people with cancer have a tumour. if the tumour does not spread to other parts of the body it is benign, if it spreads to the other parts of the body it is malignant. a benign tumour is easier to dealth with as it can be cut out. once the tumour spreads there may be many cancer cells all over the body.

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Infectious Diseases And Antibiotics

fungi: athletes foot, bacterica: cholera, viruses: flu, protozoa: malaria

infectious diseases spread: steps to control malaria. 1. sleeping under a mosquito net. 2. draining the areas of stagnent water. 3. insectisides to kill mosquito

incidence of disease, rate of new cases in a population each year.

climate: vectors multiply rapidly.

socio-economic factors: cholera is high in countries

antibiotics used to kill pathogens, doesnt work in viruses

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Immunity

pathogeons: skin, tears, stomach acid, blood clotting when cut, mucus in thr airways.

white blood cells: phogocytes engulf the pathogeons lymphocytes produce antibodies

each pathogeon has a particular antigens, its a particular shape.

immunisation makes people immune to a diease without them having the actual disease. a small amount of dead pathogeon is intoduced to the body, the body will then fight the disease and then if the disease is ever introduced to the body again, the body will be able to fight it.

bird flu was an epidemic as was swine flu and ebola.

active and passive immunity, active is where you can make your own antibodies, passive is where you cannot make your own antibodies.

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The Eye

pupil, iris, retina, cornea, lens, optic nerve, blind spot, the optic nerve leaves the eye.

binocular and monocular: animals have both eyes facing forward and both eyes focus on the the same thing. the eyes on each side of the head is monocular vision.

problems with vision: red-green colour blindess is inherited people cannot tell the difference between red and green colours. people with ling sight can see things in thr distance clearly and vise versa with short sighted.

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The Nervous System

stimuli are changes.

structure of the nervous system, central nervous system. brain and the spinal chord, periphera; nervous system nerves taking infomation from sense organs.

sense organs: skin: pressure, temperature, touch, pain. tongue: chemicals in food. nose: chemicals in air. eyes: light. ears: sound. sent by neurons.

reflex actions, a fast response to immediate pain. stimulus--receptor--sensory neurone--relay neurone--motor neurone--effector--response. reflex arc synapses are gaps between neurones.

effectors are glands or muscles that carry out a responce, respond by contracting g;and by secreting chemical substances

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Drugs

alters the way your body or brain work. prescribed because have side effetcs, interfere with other medicine harmful to patient, be harmful if taken too often.

properties of drugs people become tolerent to them nausia, poop, sick, hallucin, shakes.

rehab go to special centre

types of drug: depressant, alcohol, slow down. painkiller, paracetemol, block nerve endings. stimulant, nicotenes, increase performance. anabolic: develop hallucinoges. LSD: distort

Illegal drugs: rated from class A-C  Ceing less dangerous. A being very dangerous.

testing on labratory animals,andomised blind trail.

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Tobacco and Alcohol

produces carbon monoxide, nicotine, tar and particulates 30 years will develop to lung cancer.

carbon monoxide reduces oxygeon, makes the heart work harder, tar irritsnt causes cancer, smokers cough. small particles, accumulate in  the lungs nicotine addictive increases heart rate

to relax, depressant, short term: blurred vision, speech, confusion, violent, unconsiousness. long term: cirrhosis, brain damage, fetus, weight gain, diabetes

drivers and piolets: impirs judgement, and slows down reaction times, having an accident is greatly increased.

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Controlling Body Temperature

cells will not function if they are the wrong temperature, not enough water, too mmuch carbon dioxide on blood balencing is called homeostasis

37 degrees celcius, is core fingers and toes will be cooler.

measured by clinical themometer strips digital.

above 40 degrees celcius can cause a heat stroke below 35 degrees celcius can cause hypothermia.

blood carries excess heat away

heat in cold conditions resperation, shiver, vasoconstriction, exercise, more clothes loses heat when not vasodialation sweat, fewer clothes

negative feedback the level change away from steady, sense organ, send infomation to the brain, back to the body, starts to rebalance

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Controlling Blood Glucose

hormones are created from glands. travel to target organ, regulate, co-ordinate, usually work slowly, bar adrenaline, thyroid gland: produce adrenaline pancreas produces insulin overies (female) estrogeon. testes (male) testosterone.

insulin regulates blood glucose the pancreas creates insulin, travels in blood to liver, liver take up glucose, change it into glycogeon

type one diabetes: the persons own immune system has destroyed the cells in the pancreas that make insulin. this can be controlled with insulin injections at meal times. patients should also eat a balanced diet and take exercise.

type 2: ocurs in later life. it may be linked with being over weight. the persons cells do not respond to insulin and their pancreas may also not make enough insulin. may be controlled by eating a balanced diet, with more fibre and less sugar. people may also take medicines to make their pancreas more insulin. in some cases they may need insulin injections.

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Controlling plant growth

plant as well as animals respond to stimuli, changed in their enviroment, plants make chemical ones that control and coordinate. plants grow towars the light, if you want them to grow straight you have to keep turning them. a plant response to a stimulus is called  a tropism

phototropism- if the plants grow towards the light they are positively phototropic. they make a plant hormone called auxin. this moves through the plant in solution. when light strikes one side of the shoot tip. this causes the shoot tip to bend over, this increases the plants survival because it needs light to photosynthesise and make food.

auxin is made in the shoot tip and uneavenly distributed when the shoot is exposed to light from one side. the auxin moves down the stem and causes cells on the side of the shoot furthest from the light to elongate more than those nearest the light.

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Controlling plant growth

plant as well as animals respond to stimuli, changed in their enviroment, plants make chemical ones that control and coordinate. plants grow towars the light, if you want them to grow straight you have to keep turning them. a plant response to a stimulus is called  a tropism

phototropism- if the plants grow towards the light they are positively phototropic. they make a plant hormone called auxin. this moves through the plant in solution. when light strikes one side of the shoot tip. this causes the shoot tip to bend over, this increases the plants survival because it needs light to photosynthesise and make food.

auxin is made in the shoot tip and uneavenly distributed when the shoot is exposed to light from one side. the auxin moves down the stem and causes cells on the side of the shoot furthest from the light to elongate more than those nearest the light.

geotropism is the response of a plant to gravity, roots grow downwards in response to the pull of gravity. auxins may be involved in this response byt other chemicals inhibit growth may also be a part.

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Variation

some characteristics are determined by the eniroment, some by genes, and some by both genes and enviroment. determined by the enviroment: scars, learning to speak a language. if you get scars and then have a child your children will not gain the same scars. characteristics gianed  by genes, eye colour, earlobe shape, nose shape.

genes are particular regions of chromosomes, the thread-like structures inside the nucleus of each cell. chromosomes are made of chemical claled DNA each gene is a length of DNA. each gene controls the development of a particular characteristic.

23 matched pairs of chromosomes,

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causes of genetic variation.

mutations, formation of gametes and fertilisation can all produce variation. mutations can be caused by chemicals (tar) in tobacco smoke, chemicals used for dying materials, ultraviolet radiation in sunlight, ionising radiation like x-rays and gama rays. 

a mutation may change a gene to a different version, called an allele. it still codes for the same characteristics but will produce a slightly different version of the characteristic. the gene for an earlobe has two alleles: one codes for free lobes and the other codes for the attached lobes.

gametes are special sex cells. they contain only 23 chromosomes, this is half the normal body cells,female gametes are eggs, make gametes are sperms.  during cell division the chomosomes in each pair may swap pieces with each other, giving tem different combinations of alleles, but still remaining the same gene.

during the fertilisation process, the process is random, and this produces genetic variation. each egg produced by the mother is genetically different from the other eggs she makes. the father can make many sperms and any one of them could join with the egg. the gametes fuse toether, resulting in a fertilised egg, which will make a baby. 

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Human Characteristics

you have 23 pairs of chromosomes in the nucleus of all body cells, i yo have XX chromosomes you are female and if you have Xy you are a male. 

the genes you inherit from your parents detemine your genotype, the physical expression of the genes you carry for a paricular characteristic is you phenotype. if you have two different types of gene you are hetrozygous. if they are the same gene they are homozygous 

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Inherited disorders

example of inherited disorders are: cystic fibross, sickle cell anaemia, red-green colour blindness. 

not all mutations are harmful, early hmans who lived in africa and had dark skin which protected them from sunburn, a mutation game them pale skin would be harmful, however as humans migrated to areas less inense in sunlight. pa;e skin was useful. this was because it would allow the uns less intense rays to penetrate the skin enough to make vitamin D. this allows us to absorb calcium from food this prevnts rickets. 

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