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
When does anaerobic respiration take place?
In the absence of oxygen
Product of anaerobic respiration?
lactic acid
Products of aerobic respiration?
CO2 and water
Which method of respiration transfers more energy?
Aerobic
What do both aerobic and anaerobic respiration use?
Glucose
What solution indicates the presence of protein?
Biuret solution turns from blue to pink/purple
Explain how malaria is spread from person to person
The pathogen is carried by a mosquito which acts as a vector (carry and spread the disease) The mosquito passes it between people when it bites them.
What is meant by a vector?
a vector is any organism that facilitates the spread of a disease. Vectors do not inherently cause diseases but are mere vehicles of the germs that cause disease.
Describe how monoclonal antibodies are made
mouse injected with chosen antigen from pathogen.
B lymphocytes taken from mouse as they produce antibodies against antigen
fused with tumour cell= hybridoma
hybrdoma cells cloned to produce many identical cells all producing monoclonal antibodies
antibodies then collected an purified
What are monoclonal antibodies currently used for?
Pregnancy tests, they use antibodies to the hormone released (only in pregnant women) so the hormone binds to the antibodies and is carried up the stick by the urine with the blue beads attached to the hormone. They then bind to the antibodies on the strip and the blue beads get stuck turning it blue.
What effect does a vaccine has on the number of cases of the disease?
White blood cells quickly respond and produce anti-malaria(any disease) antibodies against it
If larger % vaccinated then less people can pass it on so it would help prevent spread of disease
vaccination prevents anybody catching the disease
Creates immunity to the people receiving the vaccine.
What molecules are formed from nitrate ions and glucose?
Amino acids
What is a limiting factor?
A factor that is preventing something from happening as quickly as it could
How can bacteria make us feel ill?
By producing toxins that damage your cells and tissues
What is a tissue?
A group of similar cells
Why is the nerve cell the shape it is?
Branched connections at their ends to connect to other nerve ells and forms a network throughout the body to carry electrical signals
What are chromosomes?
Coiled up lengths of DNA molecules
What is the name of the process by which bacteria divide?
Binary Fission
Name 3 ways to make sure bacteria hasn’t been contaminated (in culturing microorganisms experiment)
Keep upside down to prevent condensation dripping onto agar surface.
Put inoculating loop through hot flame (sterilise)
Petri dishes must be sterilised by heating at a high temp
Two ways embryonic stem cells could be used to cure diseases.
Insulin producing cells for people with diabetes
Healthy person can give bone marrow to replace faulty blood cells
Why are people against stem cell research?
Each embryo is viewed as a potential human life
Surgical procedure so risks mother.
How is a phloem cell specialised?
Very few subcellular structures to allow more to flow through them
describe events of the cell cycle that need to occur before mitosis can begin
The cell has to grow and increase the amount of mitochondria and ribosomes.
It also needs to duplicate its dna ready for the new cells
Two things that help to maximise the rate of binary fission?
Warm environments and lots of nutrients
How can stem cells be used to preserve rare plant species?
They can produce clones as they have meristem which can differentiate into any type of plant cell.
They can also grow crops of identical plants with disease resistance.
Give 3 adaptations of exchange surfaces that increase the efficiency of diffusion
lots of blood vessels to get stuff into and out of the blood quickly
thin permeable wall for quicker diffusion (less distance)
high SA so many substances can go at once.
How are leaves adapted to maximise the amount of CO2 getting into their cells?
Flattened shape increases SA
Air spaces inside the leaf increase the area so more chance for CO2 to enter cells
Where is protease produced?
Stomach, pancreas, small intestine.
Salivary glands produce which enzyme?
Amylase
Where is lipase produced?
Pancreas and small intestine
what is the cell cycle?
The process of cells dividing.
Where is amylase produced?
Salivary glands, small intestine and pancreas
what does large intestine do?
absorbs excess water from food
