Improvements to paper 1 Flashcards
What component in the blood is responsible for it clotting?
platelets
Name 3 ways white blood cells are adapted for their function
change shape to engulf pathogens
can produce antibodies
can produce antitoxins
What is needed for muscle contraction? and which subcellular structure helps this process?
energy from respiration, which is provided by the mitochondria
Was is the function of waxy cuticles in plants?
To act as a barrier to prevent pathogens from entering
What drug has been developed from a chemical in foxgloves?
Digitalis
Name properties of an artery
Thick vessel wall (layers of muscle and elastic fibres) to withstand HIGH blood pressure and allow them to stretch and spring back due to surges
Name properties of a vein
Lower pressure blood, so walls are thinner. Wide lumen to help blood flow despite lower pressure.
Also have valves to keep the blood flowing in the right direction.
Name properties of capillaries
Thin permeable wall (one cell thick) for quick diffusion due to tiny distance to travel. (supply food and oxygen and take away CO2)
What do statins do?
Statins keep cholesterol levels down, which slows down the rate at which fatty deposits form in the coronary arteries
What do stents do?
Keep arteries open, making sure blood can pass through to heart which keeps the heart beating.
Advantages of stents
Lower the risk of a heart attack. Effective long term, and the recovery time from surgery is quick.
Disadvantages of stents
Surgical procedure so there’s a risk of infection or developing a blood clot.
Advantages of statins?
statins may also prevent some other diseases.
reduce risk of strokes, heart disease and heart attacks.
Disadvantages of statins?
Have to remember to keep taking them so could forget.
Cause negative side effects e.g. headaches
takes time for their effect to kick in.
Why are drug trials carried out on healthy volunteers before patients?
To make sure side effects don’t have an effect on the body when working normally
What variable must be controlled in a double blind trial?
equal mix of age/genders.
Why is it important that a blind trial selects patients randomly?
To remove bias.
Why is it sometimes seen as unethical to prescribe somebody a placebo?
Patients with the placebo could become very ill without proper treatment.
What effect is cystic fibrosis likely to have on gas exchange?
Gas exchange less efficient as mucus blocks parts of alveoli reducing their SA.
What smaller molecules make up a lipid
3 molecules of fatty acid and one glycerol molecule.
Give two ways energy is used for respiration
to keep warm, and contracting muscles & movement