Biology B1

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  • Created by: .n.
  • Created on: 12-05-16 17:51
Whats the difference between fit and healthy?
Fitness is the level of physical activity a person is able to do(or how strong/flexible/agile they are). Helath is free from disease.
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What increases blood pressure?
smoking, being under stress, high intake of salt, high intake of alcohol, being overweight
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Explain how smoking increases blood pressure.
Carbon monoxide takes the place of oxygen in red blood cells and the heart has to pump faster to get the same amount of oxygen around the body. Nictotine is a stimulant and causes the heart to speed up.
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How can narrow arteries lead to a heart attack?
the heart is supplied with oxygen through the conorary artieries. If these become blocked by a plaque the heart recieves less oxygen as blood flow is restricted. If a thrombosis (blood clot) happens in an already narrow artery, blood flow is cut off.
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Why are plants second class protiens?
They dont contain all of the essential protiens that the body needs, only some. This is why vegitarians need to eat protiens form a wide range of plants to make sure they get a range of amino acids.
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What causes kwashiorkor?
Eating too little protien. It is common in developing countries where protiens are difficult to come by due to over population and a lack of money in agriculture.
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What is a parasite?
An organism that lives on another organism and often causes harm.
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How do white blood cells destroy pathogens?
By engulfing them, By producing antitoxins, By producing antibodies that lock onto the surface of a pathogens surface.
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How does immunisation work?
Harmless pathogen given which carries the antigens, Antigens trigger immune respinse in white blood cells, which then produce antibodies. Immunity remains because memory cells are produced.
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How are drugs tested before being released for public use?
Tested on computer models to simulate a human response, This identifies which drugs look promising enough to be tested at the next stage but not accurate as seeing affects on a live organism.
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How are drugs tested before being released for pulic use?(2)
Tested on syntheticall made human tissue, Shows affects on that one part but doesnt show affect on large organ systems, e.g the respiratory system.
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How are drugs tested before being released for public use?(3)
Tested on animals, some think it is cruel to use animls however it is the best way to test the affects of a new drug to make sure its safe for human consumption.
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Risks and benefits of immunisation?
Risks; cant be vaccinated if you are already ill, Possible link between vaccines and other diseases, Short term side affects. Benefits; If more people are immunised then diseases dont spread as easily, and individuals dont get sick.
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What is the difference between antibiotics and antivirals?
Antibiotics KILL bacterial cells, Antiviral drugs stop viruses from reproducing.
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What is the affect of depressants on the synapses?
Depressants bind with receptor molecules, blocking the transmission of impulses.
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What is the affect of stimulants on the synapses?
Stimulants cause more neurotransmitters to cross the synapses.
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How can the liver become damaged as it breaks down alcohol?
The liver breaks down alcohol and produces some toxic products. If you drin too much and these toxic products are left in the liver, the liver cells start to die. this forms scar tissue that stop blood from reaching the liver. This is called Cirrhosi
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describe the path of light through the eye.
The cornea reflects light onto the lens, The lens focuses light onto the retina, and sends impulses to the brain and a picture is made
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How does the eye focus on a distant object?
The cillary muscle RELAXES, The suspensory ligaments TIGHTEN and the lens is LONG AND THIN. This means light is LESS refracted.
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How does the eye focus on close objects?
The cillary muscle CONTRACTS, The suspensory ligaments SLACKEN, The lens is THICK AND FAT. This means light is refracted MORE.
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What causes long-sighted vision?
Long sighted people are unable to focus on near objects, This occurs when the lens doesnt refrect light enough or the eyeball is too short. The images of near objects are brought into focus behind the retina. This can be fixed with a convex lens.
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What cause short-sighted vision?
The lens is too thick, or the eyeball is too long. The light focuses infront of the retina. This can be fixed with a CONVEX lens.
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Describe the reflex arc.
Stimulus, Receptor, Sensory Neurone, CNS, Motor Neurone, Effector, Response.
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Describe the spinal reflex arc.
Stimulus, receptor, sensory neurone, relay neurone, motor neurone effector, response
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How do neurones transmit information around the body?
Electrical impulses are passed along the axon of the cell, then to other neurones across the synapses.
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How does an impulse cross the synapse?
the electrical impulse at the end of one neurone triggers the release of transmitter chemicals which diffuse across the gap between neurones.The chemicals bind to receptor molecules in the membrane of the next neurone. This starts a new electrImpulse
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Define homeostasis
Maintaining a constant internal environment.
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How do negative feedback mechnisms work?
They work automatically to keep a constant internal environment. If a chnage is detected a response to counteract the change is triggered. It only works within certain boundries.
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WHat happens when you are too hot?
Hairs lie flat, lots of sweat is produced to remove heat as it evapourates, blood vessels at the surface/close to the skin widen to allow more blood flow at the surface and ore heat can radiate to surroundinga. This is called VASODILATION
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What happens when you are too cold?
Hairs stand on end to trap air, Very little-no sweating, Blood vessels near the surface constrict in VASOCONSTRICTION to limit heat lost to surroundings, Shivering because the movement in your muslces creates heat.
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How does the brain control body temperature?
The thermoregulatory gland in the brain detects changes in temperature and responds using hormone and nervous reponses to counteract the change
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What are auxins?
Plant growth hormones; they move through the plant in solution; they respond to light and gravity (phototropism and geotropism)
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How does auxin make plants grow?
detects light in the tip of the plant, if more light is detected on one side, the auxin elonates the cell on the shady side so the plant grows towards the light.
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Give three ways plant growth hormones are used commercially.
Selective weedkillers, Fruit ripening(delay or accceleration), Control of dormancy in seedlings.
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What is an allele?
A different form of the same gene, e.g. the allels for the eye colour gene include brown (dominant) and blue(recessive)
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explain the difference between heteroezygous and homozygous
heterozygous is two different alleles of the same gene in a person, Homozygous is the same two alleles of a gene.
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Other cards in this set

Card 2


What increases blood pressure?


smoking, being under stress, high intake of salt, high intake of alcohol, being overweight

Card 3


Explain how smoking increases blood pressure.


Preview of the front of card 3

Card 4


How can narrow arteries lead to a heart attack?


Preview of the front of card 4

Card 5


Why are plants second class protiens?


Preview of the front of card 5
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