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132 Cards in this Set

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  • Back
How is blood pressure measured?
In millimetres of mercury/mmHg
What are the two measurements of blood pressure?
Systolic and Diastolic pressure.
What is systolic pressure?
The maximum pressure the heart produces.
What is Diastolic pressure?
The blood pressure between heartbeats.
What can cause blood pressure to increase?
Stress, high alcohol intake, smoking and being overweight.
What can cause blood pressure to decrease?
Regular exercise and a balanced diet.
What can high blood pressure cause?
Blood vessels to burst which can cause a stroke or damage to the kidneys.
What can low blood pressure cause?
Dizziness and fainting because the blood supply to the brain is reduced, and poor circulation to other areas such as the fingers and toes.
What is the difference between fitness and health?
Fitness is the ability to do physical activity and health is being free from diseases such as those caused by bacteria and viruses.
How can your general level of fitness be measured?
By your cardiovascular efficiency.
What activities are there to measure your fitness?
Strength - By the amount of weight lifted
Flexibility - By the amount of joint movement
Stamina - By the time of sustained exercise
Agility - By changing direction many times
Speed - By a sprint race
Why should ways of measuring fitness be evaluated?
To check effectiveness in particular situations.
How does smoking increase blood pressure?
Carbon monoxide in cigarette smoke causes the blood to carry less oxygen, this means that heart race increases so that the tissues receive enough oxygen.
What does nicotine in cigarette smoke do?
Directly increase heart rate.
What are the effects of carbon monoxide on the body?
Carbon monoxide decreases the oxygen carrying capacity of blood. It combines with haemoglobin, preventing it combining with oxygen so less oxygen is carried.
What is heart disease caused by?
Restricted blood flow to the heart muscle.
What is the risk of getting heart disease increased by?
A high level of saturated fat in the diet, which leads to a build up a cholesterol in the arteries.
High levels of salt, which can increase blood pressure.
What is the narrowing of arteries caused by?
Plaques in the coronary arteries.
What happens when the coronary arteries are narrowed?
They reduce blood flow to the heart muscle and make blood clots or thrombosis more likely to occur, which will also block the artery.
What does a balanced diet contain?
Carbohydrates, fats and protein.
What are carbohydrates made up of?
Simple sugars such as glucose.
What are proteins made up of?
Amino acids.
What are fats made up of?
Fatty acids and glycerol.
What are the factors that can vary a balanced diet?
Age, gender, level of activity, religion, being vegetarian or vegan, food allergies.
If you eat too much fat or carbohydrate, how are they stored in the body?
Carbohydrates are stored in the liver as glycogen or converted into fats.
Fats are stored under the skin and around organs as adipose tissue.
Although proteins are essential for growth and repair, they cannot be stored around the body.
How do you calculate EAR?
EAR = 0.6 x body mass in kg
What does too little protein in the diet cause?
Kwashiorkor.
Why is kwashiorkor more frequent in underdeveloped countries?
Because of overpopulation and no money to improve agriculture.
What factors affect a persons EAR?
Body mass, age, pregnancy or breast feeding.
Although proteins can not be stored in the body, what happens to some amino acids?
Can be converted by the body into other amino acids.
What are proteins from meat and fish called?
First class proteins.
What are first class proteins?
Proteins from meat and fish that contain all the essential amino acids that the body cannot make.
Why are plant proteins called second class proteins?
They do not contain all the essential amino acids.
How do you calculate BMI?
BMI = mass in kg / (height in m)2
Why do some people become ill?
(To do with food)
Because they choose to eat less than they need due to low self esteem, poor self image or desire for what they think is perfection.
What is malaria caused by?
A protozoan called Plasmodium which feeds on human red blood cells.
What is plasmodium carried by and how is it transmitted to humans?
It is carried by mosquitoes which are vectors (not affected by the disease) and transmitted to humans by mosquito bites.
What is a parasite?
An organism that feeds off another living organism, causing it harm.
What has knowledge of a mosquito's life helped?
Stop the spread of malaria and helped to develop new treatments for malaria.
How can the spread of malaria be controlled?
-Draining stagnant water
-Putting oil on the water surface
-Spraying insecticide
How can changes in lifestyles reduce the risk of cancers?
Not smoking reduces the risk of lung cancer
Using sunscreen reduces the risk of skin cancer
What are benign tumours?
Tumours that divide slowly, like warts, and are harmless.
What type of tumours are cancers?
Malignant tumours; the cells display uncontrolled growth and may spread.
What should be considered?
(To do with cancer idek)
Ways of interpreting data on cancer and survival rates should be considered.
What do pathogens produce?
The symptoms of an infectious disease by damaging the bodys cells or producing poisonous waste products called toxins.
Hwo does the body protect itself against pathogens?
It produces antibodies which lock onto antigens on the surface of pathogens such as bacterium, which kills the pathogen.
What is active immunity?
When human white blood cells produce antibodies, which is a slow process but has a long lasting effect.
What is passive immunity?
When vaccinations using antibodies from another human or animal are used, which has a quick but short term effect.
What does each pathogen have that is its own?
Its own antigens, so a specific antibody is needed for each pathogen.
What is the process of immunisation?
It starts with an injection containing harmless pathogens which carries antigens. The antigens trigger a response by the white blood cells, which produce the correct antibodies. Memory cells remain the body, providing long-lasting immunity of that disease.
What does immunisation carry?
(In terms of risks)
A small risk to the individual, but it avoids the potentially lethal affect of the pathogen, as well as reducing the risk of spreading the disease.
What are antibiotics against?
Bacteria and fungi.
What are antiviral drugs against?
Viruses.
Whats the difference between an antibiotic and an antiviral drug?
An antibiotic destroys a pathogen, an antiviral drugs slows down a pathogens development.
What are new treatments tested using?
Animals, computer models and human tissue before human trials.
What is a placebo?
A harmless pill used as a comparison in drug testing so the effect of a new drug can be assessed.
What happens in a blind trial?
The patient does not know whether they are receiving a new drug or a placebo.
What happens in a double-blind trial?
Neither the patient nor the doctor know whether a placebo or a new drug is being used.
Why are blind trials used?
To prevent a 'feel-good factor' and a biased opinion.
What has excessive use of antibiotics caused?
Resistant forms of bacteria being more common than non-resistant forms. For example, MRSA has thrived, causing serious illness.
What happens to light rays by the cornea and lens?
They are refracted (bent) by the cornea and lens.
What does the retina contain?
Light receptors, some are sensitive to different colours.
What does binocular vision do?
Helps to judge distance by comparing the images from each eye, the more different they are; the closer away the object.
What is accommodation?
When the eye focuses light from distant or near objects by altering the shape of the lens.
How does the eye focus on near objects?
The ciliary muscles contract and the suspensory ligaments slacken, so the lens is a more rounded shape due to its elasticity.
How does the eye focus on distant objects?
The ciliary muscles relax and the suspensory ligaments tighten so the lens has a less rounded shape.
What is red-green colour blindness caused by?
A lack of specialised cells in the retina.
What happens in long sight?
The eyeball is too short or the lens is too thin, so the image is focused behind the retina.
What happens in short sight?
The eyeball is too long or the lens is too rounded so the lens refracts too much light, so the image is focused infront of the retina.
What corrects long and short sight?
Corneal surgery, glasses or contact lenses.
What type of lens is used to correct long sight?
A convex lens.
What type of lens is used to correct short sight?
A concave lens.
What are nerve cells called?
Neurones
What do nerve impulses pass along?
The axon.
What are the links in a reflex arc?
Stimulus > receptor > sensory neurone > central nervous system > motor neurone > effector > response
What is the pathway for a spinal reflex?
Receptor > sensory neurone > relay neurone > motor neurone > effector
How are neurones adapted?
They have long, have branched ending to pick up impulses and have an insulator sheath.
What is the gap between neurones called?
A synapse.
What happens upon the arrival of an impulse?
It triggers the release of a transmitter substance, which diffuses across the synapse. The transmitter substance binds with the receptor molecules in the membrane of the next neurone causing the impulse to continue.
What are the different types of drugs?
Depressants (alcohol)
Painkillers (paracetamol)
Stimulants (nicotine)
Performance enhancers (steroids)
Hallucinogens (lsd)
What do depressants do?
Block the transmission of nerve impulses across synapses by binding with receptor molecules in the membrane of the receiving neurones.
What do stimulants do?
Cause more neurotransmitter substances to cross synapses.
What does cigarette smoke contain?
Chemicals that stop cilia moving.
What are cilia?
Tiny hairs found in the trachea, bronchi and bronchioles.
What is smokers cough a result of?
-Dust and particles in cigarette smoke collecting and irritating the epithelial lining.
-Mucus not being moved by the cilia.
What does drinking alcohol increase?
Reaction time and the risk of accidents.
What is cirrhosis of the liver?
When the liver is damaged from breaking down toxic chemicals such as alcohol.
What is homoeostasis?
Keeping a constant internal environment.
What does homoeostasis involve?
Balancing bodily inputs and outputs
What do automatic control systems do?
Keep the levels of water, temperature and carbon dioxide steady.
What are negative feedback systems and where are they used?
They act to cancel out a change such as decreasing temperature, used is homoeostasis.
What is the optimum temperature for many enzymes?
37oC
What can a high temperature cause?
-A heat stroke (skin becomes cold and clammy, pulse is rapid and weak)
-Dehydration (loss of too much water)
What does the evaporation of sweating require?
Heat transfer form the body to the environment.
What can a low temperature cause?
-Hypothermia (slow pulse rate, violent shivering)
What is blood temperature measured by?
The hypothalamus gland in the brain.
What are reaction to temperature extremes controlled by?
The nervous and hormonal systems which trigger vasodilation or vasoconstriction.
What is vasodilation?
Vasodilation is the widening of small blood vessels in the skin. The causes to the blood to flow near the skin surface resulting in more heat transfer.
What is vasoconstriction?
Vasoconstriction is the narrowing of small blood vessels in the skin. This causes less blood flow and less heat transfer.
What controls blood sugar levels?
A hormone called insulin.
Why is hormone action slower than nervous reaction?
Hormones travel in the blood.
What is type 1 diabetes caused by?
The pancreas not producing insulin, so must be treated by doses of insulin.
What is type 2 diabetes caused by?
The body not producing enough insulin or not reacting to it, can be controlled by diet.
What does insulin do?
Converts excess glucose in the blood into glycogen, which is stored in the liver. This regulates the blood sugar levels.
The insulin dosage in Type 1 diabetes needs to vary according to what?
The persons diet and activity. Strenuous exercise needs more glucose to be present in the blood, so less insulin is required.
What is phototropism?
A plants response to light.
What is geotropism?
A plants response to gravity.
Why do parts of a plant respond in different ways?
A plants shoot is positively phototropic and negatively geotropic.
A plants roots are negatively phototropic and positively geotropic.
What are auxins?
Plant hormones that move through the plant solution.
Where are auxins made?
In the shoot and tip.
Where are different amounts of auxin found?
In different parts of the shoot where the tip is exposed to light.
Where is more auxin found?
In the shady part of shoots.
What does a higher amount of auxin do?
Increase the length of cells, therefore, the increase in cell length on the shady side of the shoot curvature of the shoot towards the light.
What are the commercial uses of plant hormones? (4)
-As selective weedkillers, which kill specific weeds and increase crop yield
-As rooting powder to increase root growth of cuttings
-To delay or accelerate fruit ripening to meet market demands
-To control dormancy in seeds
What are the two different types of human characteristic?
Dominant and recessive.
What are alleles?
Different versions of the same gene.
What is there a debate over?
How much nature or nurture affect intelligence, sporting ability and health.
What do dominant and recessive characteristics depend on?
Dominant and recessive alleles.
When are dominant and recessive alleles expressed?
Dominant alleles are expressed when present but recessive alleles are expressed only in the absence of the dominant allele.
What do most body cells have the same number of?
Chromosomes.
How many pairs of chromosomes do humans have?
23
What do sex chromosomes determine?
The sex in mammals.
What is the difference in sex chromosomes?
Females have identical chromosomes XX, Males have different chromosomes XY
Why is there an equal chance of offspring being male or female?
A sperm will carry either an X or Y chromosome, all eggs will carry an X chromosome. There is a random chance of which sperm fertilises an egg.
What is genetic variation caused by?
-Mutations, which are random changes in genes or chromosomes
-Rearrangement of genes during the formation of gametes
-Fertilisation which results in a zygote with alleles from the father and mother
What does a monohybrid cross involve?
Only one pair of characteristics controlled by a single gene, one allele being dominant and one recessive.
What do homozygous and heterozygous mean?
Homozygous means having identical alleles, heterozygous means having different alleles.
What is a genotype and a phenoype?
A genotype is a persons genetic makeup, a phenotype is which alleles are expressed.
What are inherited disorders caused by?
Faulty genes.
When are many personal and ethical issues raised?
-In deciding to have a genetic test (a positive result could alter lifestyles, career, insurance)
-By knowing the risks of passing on an inherited disorder (whether to marry/have a family)
What are inherited disorders caused by?
Faulty alleles, most of which are recessive.
How is it possible to predict the probability of inheriting a disorder?
By interpreting genetic diagrams.