B1- OCR Gateway Biology Science

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  • Created by: Georgia
  • Created on: 29-12-11 19:01
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Healthy- no infections or disease
Fit- how well you can perform physical tasks... strength, speed, agility,
flexibility, stamina
Cardiovascular efficiency- ability of heart to supply muscles with oxygen...
measured by stamina
Blood pressure- pressure is needed to pump blood to body parts...
Low blood pressure -poor circulation -tissues get less food and oxygen
High blood pressure -smoking -overweight -too much alcohol
Blood vessels burst -strokes -brain damage -kidney damage
Smoking- carbon monoxide combines with haemoglobin in red blood cells,
instead of oxygen- heart rate has to increase to get enough oxygen to
tissues... heart contracts more... increases blood pressure.
Nicotine increases heart rate... heart contracts more often...
increases blood pressure.
Poor diet- cholesterol=fatty substance and high salt levels
Some cholesterol for making cell membranes... too much- build up in arteries

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Makes plaques in artery wall... narrow arteries- restricts blood flow... heart
Narrow arteries... 1) heart muscles supplied with blood- coronary arteries
2) narrowed- blood flow restricted...…read more

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Water Prevent
Some amino acids- not made by body... have to get from diet- essential
amino acids.
All essential amino acids can be attained by eating meat (produced by animals)
- first class proteins.
Plant proteins don't contain all essential amino acids- second class proteins.…read more

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Different diets... religious, e.g. Hindus don't eat cows, sacred... personal,
e.g. vegetarians, cruel to eat meat... medical reasons, intolerance or allergies
Too little protein- kwashiorkor... swollen stomach
Overpopulation- demand for protein-rich food is more than amount that's
Money- not enough to invest in agriculture... without good farming
techniques cannot grow enough protein-rich food
EAR (Estimated Average daily Requirement) of protein (g) = 0.6 x body mass
Teenagers- more, growing
Pregnant and lactating women- more, baby needs it
Anorexia and bulimia...…read more

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­ 40 Moderately obese
Above 40 Severely obese
Not always reliable- athletes, muscle. Alternative= measuring % body fat
Infectious diseases- pathogens which are microorganisms.
1) Fungi ­ e.g. athlete's foot
2) Bacteria ­ e.g. cholera
3) Viruses ­ e.g. flu
4) Protozoa (single-celled organisms) ­ malaria
Symptoms- caused by cell damage or toxins produced by pathogens
Caused by protozoa
Carried by mosquitos
Protozoan is parasite- organism that lives off another organism
(host) and often causes it harm
Mosquitos- vectors...…read more

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Producing antibodies...
a) Antigens- unique molecules of surface of each pathogen
b) When white blood cells find foreign antigen they'll produce antibodies-
which lock onto and kill invading cells. Antibodies specific to pathogen
c) Antibodies produced rapidly- kill all similar bacteria or viruses
d) Some white blood cells stay in blood after pathogen has been fought
off... memory cells... same pathogen again, cells remember
antibodies... immunity
Immunisation (vaccination) stops infections
Injecting dead or inactive pathogens... carry antigens but harmless
If live pathogens ever occur...…read more

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Some bacteria- naturally resistant to certain antibiotics... misuse (over
prescription) increased rate of development of resistant strains
Antivirals- drugs that stop viruses from reproducing
Cancer- cells dividing out of control tumour (mass of cells)
Benign Malignant
Grows until no more room Grows and spreads to other places
Cells stay where they are Dangerous
Not normally dangerous Can be fatal
Healthy lifestyle and diet- reduces risk of some cancers
E.g. not smoking... less chance of lung cancer
E.g. eat less processed meat and more fibre...…read more

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Open label Easy to conduct Risk of bias
Blind Medium to conduct Doctor may influence
Double blind No bias Hard to conduct
Drugs- substances which alter the way the body works e.g. illegal or medically
useful such as antibiotics... prescription or over-the-counter
Addictions...physical need for the drugs (not psychological) caffeine,
withdrawal symptoms... headaches, shakiness and irritability
Tolerance... body gets used to having it... need higher dose for same effect.…read more

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Painkillers Aspirin Reduces number of
painful stimuli at nerve endings
Performance Anabolic steroids e.g.…read more

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Drunk- impaired judgement -poor balance -poor coordination
-slurred speech -blurred vision -sleepiness
Legal alcohol driving limits- 80mg alcohol in 100mg blood
Lifestyle guidelines- women- 14 units per week
- men- 21 units per week
1 unit... half pint of beer OR small glass of wine OR pub measure of spirits
Nicotine- addictive
Carbon monoxide, tar and particulates
1) Heart disease
Carbon monoxide reduces oxygen carrying capacity of blood. Heart
muscle... not enough oxygen...…read more


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