B1 Flashcards
Describe the factors that increase blood pressure.
The factors that increase blood pressure are smoking, eating too much salt, being overweight, stress, drinking too much alcohol regularly, eating a lot of saturated fat.
Describe the factors that decrease blood pressure.
Blood pressure can be reduced by not smoking, reducing salt in the diet, maintaiing a healthy weight, reducing stress, reducing alcohol consumption and saturated fat intake.
Explain how diet can increase the risk of heart disease.
The liver makes cholesterol from saturated fat. Cholesterol is carried in the blood and may be deposited in artery walls, forming fatty plaques. These deposits narrow the arteries and restrict blood flow causing an increased blood pressure.
Recall what proteins, fats and carbohydrates are made from
Proteins are made of amino acids. Fats are made of fatty acids and glycerol. Carbohydrates are made from glucose.
Explain factors that affect how a balanced diet will vary.
A balanced diet is not the same for everyone. It may vary according to age, gender, religion, medical reasons eg diabetes, allergies or personal choice eg vegetarian / vegan.
explain why protein deficiency is linked to developing countries
Protein deficiency is linked to developing countries because they do not eat enough protein. This is because of over population and/or limited food production.
How is EAR (Estimated Average Requirement) of protein calculated?
EAR in g = 0.6 x body mass in kg
How is BMI (Body Mass Index) calculated?
BMI is calculated by dividing a person’s mass in kg by their height in metres, squared.
What are the causes of infectious disease?
The causes of infectious disease are bacteria, viruses, fungi and protazoa.
How do pathogens cause the symptoms of a disease?
Pathogens cause symptoms by invading cells and releasing toxins.
Explain the difference between active immunity and passive immunity.
Active immunity is created when your body makes it’s own antibodies. Passive immunity is created when you receive antibodies rather than make them eg in a vaccination.
Describe how new treatments are tested.
New medical drugs have to be tested to ensure that they work, and are safe, before they can be prescribed. There are three main stages of testing. 1) The drugs are tested using computer models and human cells grown in a laboratory. 2) Drugs that pass the first stage are tested on animals. 3) Drugs that have passed animal tests are used in clinical trials. They are tested on healthy volunteers to check that they are safe. Very low doses of the drug are given to begin with. If there are no problems, further clinical trials are done to find the optimum dose for the drug.
Describe the function of the cornea.
The cornea refracts (bends) light as it enters the eye.
Describe the function of the iris.
The iris controls how much light enters the pupil.
Describe the function of the lens.
The lens focuses light on to the retina.
Describe the function of the retina.
The retina contains light receptors.
Describe the function of the optic nerve.
The optic nerve carries impulses from the eye to the brain.
Explain how short sight is caused.
Someone with short-sightedness can see near objects clearly, but can’t focus properly on distant objects. This is because the lens focuses the sharpest image in front of the retina, instead of on it.
Explain how long sight is caused.
Someone with long-sightedness can see distant objects clearly, but can’t focus properly on near objects. This is because the lens focuses the sharpest image behind the retina, instead of on it.
Describe a reflex arc.
In a simple reflex action : stimulus ? receptor ? sensory neurone ? relay neurone ? motor neurone ? effector
explain the consequences of high blood pressure
High blood pressure can cause: kidney damage, burst blood vessels, strokes.
explain the consequences of low blood pressure
Low blood pressure can cause dizziness, fainting, poor ciculation and organ failure.
explain how a thrombosis can increase the risk of a heart attack
Cholesterol deposits may lead to a thrombosis. A thrombosis in an artery supplying the heart muscle can cause a heart attack.
describe the differences between first and second class proteins
Proteins from plants are ‘second class’ proteins. Proteins from animals are ‘first class’ proteins – they provide all the essential amino acids, including those that the body can’t make.
Explain why the EAR results may vary
A growing teenager will need more protein in their diet than an adult with the same body mass. Pregnant women will also need more protein in their diet, as will new mothers who are breast feeding their baby.
Explain why each pathogen needs specific antibodies
Each pathogen needs specific antibodies because each type of antibody has has a particular shape and can lock on to a particular antigen.
Explain the process of immunisation.
Vaccination involves putting a small amount of an inactive form of a pathogen, or dead pathogen, into the body. White blood cells are stimulated to produce antibodies against the pathogen.
What is a double blind trial?
>
In a double blind trial neither the doctor or the volunteers know who is receiving the drug or the placebo.
Explain how the eye focuses light.
Light passes through the eyeball to the retina. It is refracted (its rays are bent) by the cornea and lens, so that the light is brought to a focus on the retina.
Explain how long sight can be corrected.
Long sight can be corrected with a converging lens which bends light rays inwards before they enter the eye.
Explain how short sight can be corrected.
Short sight can be corrected with a diverging lens which bends the light rays outwards before they enter the eye.
Describe the nerve transmission across 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.
Describe how mosquitos spread malaria.
Mosquitos are a vector that carry plasmodium. Plasmodium is injected in to the blood stream when the mosquito bites.
Describe a reflex arc.
In a simple reflex action : stimulus ? receptor ? sensory neurone ? relay neurone ? motor neurone ? effector
How do pathogens cause the symptoms of a disease?
Pathogens release toxins and damage cells
What are the causes of infectious disease?
The causes of infectious disease are bacteria, viruses, fungi and protazoa.
Why does each pathogen need specific antibodies?
Antibodies lock on to the antigen and so need to be a specific shape.
Name the 5 types of drugs?
>
The 5 types of drugs are : stimulants, depressants, performance enhancers, hallucinogens and pain killers.
Give an example of a stimulant.
/tr>
Some examples of stimulants are : Nicotine, caffeine, ecstasy.
Give an example of a depressant.
table>
Some examples of depressants are : Alcohol, solvents, tamazepam.
Give an example of a performance enhancer.
An example of a performance enhancer is anabolic steroids.
Give an example of a halluginogen.
An example of a hallucinogen is LSD.
Give an example of a pain killer.
Some examples of painkillers are : Aspirin and paracetamol.
Explain the basis of the legal classification of drugs
Illegal drugs are classified from Class A to Class C. Class A drugs are the most dangerous, with the most serious penalties for possession or dealing. Class C are the least dangerous, with the lightest penalties, but this does not mean they are safe to use.
What is the effect of stimulants on synapses?
Stimulants cause more neurotransmitter molecules to diffuse across the synapse
State a long term effect of alcohol.
Liver damage /Cirrhosis
State three short term effects of alcohol.
Sleepiness, impaired judgement, blurred vision, red skin due to increased blood flow.
What is homeostasis?
Homeostasis is maintaining a constant internal environment.
Explain the difference between Type 1 and Type 2 diabetes
Type 1 diabetes - the pancreas does not produce enough insulin. Type 2 diabetes - the body no longer responds to insulin.
Why can the flu not be treated with antibiotics?
Antibiotics kill bacteria. The flu is caused by a virus.
What is the effect of depressants on synapses?
Depressants bind to receptor molecules.
What is the body’s core temperature?
37 degrees celcius.
What part of the brain monitors blood temperature?
Hypothalamus
html>
How does the body decrease its temperature?
Sweating - heat evaporates away from the skin taking heat energy with it. Vasodilattion - more blood can flow through capillaries next to the skin so more heat can be lost.
How does the body increase its temperature?
Shivering - heat energy is released by muscle contraction. Vasoconstriction - less blood flows through capillaries so heat is not lost from the skin.
What is the name of the hormone that controls blood sugar level?
Insulin
What organ produces insulin?
r>
Pancreas
What is the name of the hormone responsible for growth in plants?
Auxin
Define a positive tropism
A plant grows towards a stimulus
Define a negative tropism
html>
A plant grows away from a stimulus
Where are auxins produced?
tml>
Auxins are produced in the shoots and tips of plants.
What effect do auxins have on plant cells?
Auxins cause cell elongation.
>
What are male sex chromosomes?
XY
What are female sex chromosomes?
XX
How many chromosomes do human cells have?
46 chromosomes / 23 pairs
html>
How many chromosomes do human gametes have?
23 chromosomes
What is an allele?
Alleles are different forms of the same gene.
What is a dominant allele?
Only one copy is needed for that characteristic to be expressed.
What is a recessive allele?
Two copies are needed for that characteristic to be expressed.
Give an example of an inherited disorder.
*Sickle cell anaemia * Cystic Fibrosis * Colour blindness
What effect does sunlight have on auxin?
Sunlight causes auxin to break down.
Explain why a plant grows towards light.
Auxins are produced in the tip. Sunlight breaks down auxin and so auxin gathers on the shady side. The auxin causes cell elongation.
What are proteins made from?
Amino acids
What are carbohydrates made from?
Glucose
What are fats made from?
Fatty acids and glycerol
