Role of receptors and nervous system in increasing heart rate
This causes neurones to be sent along the sympathetic nervous system
These are detected by the motor neurones in the heart
The medulla oblongata will send the chemical signal along the sympathetic neurone
Baroreceptors and chemoreceptors detect changes in the aorta and carotid artery
Chemoreceptors in the wall of the casteroid arteries
Action potential is sent via the accelerous nerve
Baroreceptors detect the rise in blood pH due to increased CO2 levels
The electrical impulse is changed into a chemical, in order for it to diffuse across the synapses
The central nervous system which is either the spine or the brain
A relay neurone is not used as its a reflex action and it would take too long
Neuromuscular junctions are needed to create action potentials
The AVN sends an electrical wavelength across the atria
CO2 concn increases lowering the pH. It is detected by osmoreceptors
Neurons shoot to the brain and effectors travel to the heart
The nervous system is needed to send signals to the brain via relay, motor and sensory neurones
Receptors detect the presence of oxygen and glucose required for respiration, and if that isn't present, electrical impulses are sent down the nervous system
Cellular processes leading on from acetyl-CoA
This means that acetyl-CoA can bind to receptors on synapses
Fatty acid pathway and exercise
The fatty acids can be broken down into glucose
A human's biggest energy store per cm2 is lipids
How Sterile Insect Technique could reduce transmission of the virus causing dengue
When infertile males mate, they pass on radiation to their offspring
They don't reproduce so don't pass on infertility
The previous males could have immigrated to a different community
The number decreased steadily and then did not increase almost to 0
SIT would be complementary to receptors on post-synaptic neurone so it blocks receptor sites preventing virus from binding so electrical impulse is inhibited
As the sterile male does not contain the virus, it cannot transfer the virus to another mosquito
When they breed infertile offspring will be produced so die
If the virus is sterile it cannot inject its genetic material into a host cell
They are infertile so cannot breed and produce fertile offspring so cannot pass on the genes that cause dengue
Aedes aegypti cannot reproduce and pass on the virus to offspring
The alleles for dengue are not passed on to next generation if the fertile mosquitos breed with sterile, infertile males
Infertile males mean less successful fertilisation of women mosquitos
This will increase competition for females therefore resulting in more unsuccessful offspring produced
This decreases the birth rate of offspring with A. aegypti being born
Can't reproduce so can't produce offspring with dengue fever virus
Less mosquitoes would be carrying the virus (/). The gene would bcome a stronger allele. Genetic bottleneck could occur.
There is less chance of the disease being passed on to offspring
SIT will prevent the virus being inherited by the offspring of the Aedes aegypti
They may also be less aggressive if made infertile which would cause them to bite less therefore less chance of infecting humans
The infertile males will fight and if successful will mate with other mosquitos
Infected mosquitos will eventually die out
The gene of the sterile male mosquito will be changed by radiation. The offspring will have a possibility of not being the original
It will reduce the number of insects with the allele for being a carrier
Chance of mutations is lowered, gene pool is decreased and less genetically diverse
Exposure to the sterile virus would cause an immune response
Sterile males can no longer transmit dengue to females
Even if a diseased virus tries to mate and reproduce they are unable to pass on that virus to a new generation
Eventually they would die and the virus leaves with them instead of spreading
Other female mosquitos of the same species are more likly to breed with the sterile males which will not lead to offspring production
When sterile mosquito bites a person, virus is not passed on to person. Plus sterile male can mate with virus carrying female and not produce virus offspring
The sterile males would act like a competitive inhibitor
They are able to transmit the sterile form of the virus to people
Mosquitos with viral DNA in their cells are unable to breed with other mosquitos
When the SIT are released ...
Sterile mosquitos won't pass on the virus when mating
If they get the dengue, the mosquitos cannot pass the virus onto other organisms
Mark release recapture
Capture using an ethical random procedure
Collect sample of mosquitoes using a pitfall trap
Leave enough time for mosquitoes to reintegrate into society
Mark the mosquitos, release them into their habitat, then recapture the marked ones
Release the mosquitos back into their environment and ensure there is no immigration, emigration, births or deaths
Count the number that have been marked using a UV light source
The frequency of marked mosquitos in the mosquitos captured the second time can be used to estimate the original population size by dividing 100 by the frequency
After a week capture another sample and find how many have the virus
After a period of time which is not enough for them to mate but long enough to mix randomly with the rest of the population
Collect another sample a few weeks later (or the life cycle of mosquito later)
A sample will be taken using a quadrat
The second time only the mosquitos which had been marked are counted
Nerve cell communication
This causes temporary summation
ATP
ATP is required during the sliding filament theory of muscle contraction
Difference between mouse muscles
Trained mice had more ATP activity than controlled mice
Reasons for keeping water potential the same
If the water potentials were different water would move in and out by osmosis
Water potential might enter the chloroplasts in varying amounts
There is a chance that the chloroplast may shrink and burst due to osmotic pressure
Photosynthesis - light dependent reaction?
Why was tube containing DCPIP solution + no chloroplasts set up?
As a control test/tube to ensure that equipment is washed thoroughly
As a control to see the effect of nothing on DCPIP solution
To ensure that DCPIP would only react in the correct conditions
Chlorophyll absorbed light and electrons become exited
DCPIP is reduced by reducing sugars produced in photosynthesis
Advantage of IC50 (conc of chemical inhibiting decolorisation of DCIP by 50%)
It can be tracked as it is an isotope
It is measuring the change by a smaller amount so it is more accurate
The chemicals can be judged equally
It is an enzyme so it is only specific to DCPIP
It is effective at least half the time
It shows the concentration needed to decolorise half the solution
Comparison of Arbuscular Mycorrhiza Fungi on plant growth
Data may not be larger or representative
Use of a variety of DNA probes in detecting different viruses
The DNA probe is not likely to bind in a complementary way
The scientist produced a variety of primers in case one didn't work
Different primers are complementary to different ends of genes
There may be different base sequences that code for the same respiratory disease as it is a degenerate code
The virus may cause a mutation in base sequence so the primer may no longer be complementary
Different primers must be used for different people
A different primer is needed for each of the lengths of DNA wanting to be copied
Primers are specific to active sites of RNA
Primers may need to attach to different sections of RNA depending on if the virus is present or not
Biomass and primary productivity
The left over energy is used for mitosis which produces biomass
This cannot be converted into organic ions e.g. glucose
Gene pool definition
A location where there are different frequencies of alleles
Sympatric speciation
Alleles weren't shared between the two populations, causing a change in speciation between them
Their alleles changed to their genes giving them different characteristics
Sympatric speciation arises when two members are so far from each other they adapt and develop into two separate species over time
The two populations reproductive cycles are not in sink
Palm trees only mated with palm trees with similar characteristics
The trees couldn't flower and pollinate at the same time
Alzheimers disease in Andes
They are high in the mountain so genes are more likely to mutate
Why no natural selection against it?
Natural selection mainly affects recessive alleles
Natural selection requires an overproduction of offspring, but population is small
Health and other illnesses may increase the likelihood ..
Adults with the gene can still mate
In a small town it will take a long time for this to occur
There will be no alleles that dominate it for selection
Because they are isolated, people there have to mate with the people there
People don't live long enough for the mutation to have an effect
It is isolated so the gene pool will be low
The sample size is too small to be generalised
The mutation causes a degenerate code
DNA separated into 2 strands
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