AQA biology a-level paper 2
Acetylation of DNA - ANS-acetyl businesses brought to histones, so DNA is much less tightly
wound spherical it, making it less difficult for RNA polymerase and transcriptional factors to
bind, so transcription can arise.
Allopatric speciation - ANS-When populations of a species emerge as geographically
remoted. Gene glide among them ceases (reproductive isolation). The new environment will
trigger a alternate inside the gene pool because of natural choice imposed on them.
If the populations are especially small, they may revel in a founder impact.
Selection and genetic flow will act differently on these two specific genetic backgrounds,
developing genetic variations between the two new species.
Codominance - ANS-happens where heterozygote has a phenotype this is unique from each
homozygotes.
Neither allele is dominant over the opposite; they both make a contribution similarly to the
phenotype.
Define biomass - ANS-the whole mass of organisms in a given area
define network. - ANS-all of the populations of different species dwelling and interacting in a
selected place on the identical time.
Outline area of interest. - ANS-the position and function a species has in its environment; the
way it meets its desires for food and refuge, the way it survives, and how it reproduces. A
species' niche consists of all of its interactions with the biotic and abiotic elements of its
environment.
Define populace. - ANS-a collection of people of one species that occupy the same habitat
on the identical time and are potentially able to interbreed.
Describe and explain the position of hormones in osmoregulation. - ANS-1.Osmoreceptors in
hypothalamus locate fall in water potential as they begin to decrease, inflicting hypothalamus
to supply ADH.
2. ADH goes to posterior pituitary gland, in which it is secreted into capillaries.
3. ADH goes from blood to kidneys, where it binds to receptors at the cells of of distil
convoluted tubule and amassing duct.
Four. This activates phosphorylase enzyme.
5. This reasons vesicles, which include water channel proteins, to fuse with cell surface
membrane. As a result, making it greater permeable to water.
6. Additionally increases permeability of gathering duct to urea so it passes out and lowers
water ability, so more water can pass out via osmosis.
Describe and explain the steps in the light structured reaction of photosynthesis - ANS-1.
Photoionisation: mild reaches chlorophyll in PSII, that is absorbed by an electron, which
becomes excited and movements to a higher power degree.
2. The electron passes to a provider protein in the thylakoid membrane, and is surpassed
down a sequence of carrier molecules referred to as an electron switch chain.
Three. As the electron actions down, strength is lost from the electron and is released as
ATP.
4. The lack of electron from PSII is 'refilled' by an electron produced by using photolysis,
which additionally produces hydrogen and oxygen.
, Five. The misplaced electron reaches PSI, which absorbs light power and boosts every other
electron to a better strength stage (excitation).
6. This electron also is going down an electron delivery chain.
7. This reaches the very last electron acceptor that's a proton. They combine to shape H and
decrease NADP to NADPH.
Describe and give an explanation for the stairs within the light unbiased reaction pf
photosynthesis. - ANS-1. CO2 diffuses into stroma and combines with ribulose bisphosphate
(RuBP) using the enzyme rubisco.
2. This bureaucracy an risky 6 carbon molecule, which splits into 2 3 carbon molecules,
glyercate-three-phosphate (G3P) .
3. G3P is decreased by means of NADPH to triose-phosphate (TP), that's aided through
ATP for energy.
4. TP can be converted into beneficial natural materials.
5. TP also can be reformed into RuBP using ATP.
Describe rapid twitch fibres - ANS-agreement extra rapidly and more effective however over
a shorter period of time.
Tailored for extreme exercising
have thicker and more severa myosin filament, have more glycogen, have more enzymes to
carry out anaerobic breathing, has phosphocreatine.
Describe glycolysis in respiratory. Provide internet formation. - ANS-1. Glucose is
transformed into phosphorylated glucose by means of 2ATP. This makes it very reactive, so
it splits into 2 triose phosphate (TP).
2. 2TP is then oxidised by using 2NAD and four ATP is formed to shape pyruvate.
Three. NET: 2ATP, 2Pyruvate, 2NADH, 2H+
describe krebs cycle in respiratory. Deliver net formation. - ANS-1. Acetyl co-enzyme A
combines with four carbon molecule (oxaloacetate) to shape 6 carbon citric acid.
2. CO2 is misplaced (decarboxylation), molecule is oxidised by means of NAD and ATP is
produce. This bureaucracy 5 carbon compound.
3. It's far oxidised by means of 2NADH and FAD, and is decarboxylated.
4. This forms four carbon molecule again.
Describe hyperlinks reaction in respiratory. Provide internet formation. - ANS-1. Pyruvate
diffuses into the matrix of mitochondria.
2. Pyruvate is oxidised via NAD. CO2 is misplaced. This bureaucracy acetate.
Three. Acetate and co-enzyme A combine to form acetyl co-enzyme A.
Four. NET: CO2, reduced NAD, acetyl co-enzyme A
describe oxidative phosphorylation in respiratory. - ANS-1. Reduced coenzyme passes its H
to a carrier protein inside the ETC. This splits right into a proton and electron.
2. The protons skip thru the space among internal and outer mitochondrial membrane.
Three. Electrons bypass via proteins on ETC.
Four. Protons go back back via ATP synthase in the membrane, generating ATP.
5. The protons and electrons recombine to shape H, which mixes with O to form water.
6. Oxygen is the last electron acceptor in the ETC.
Describe gradual twitch fibres - ANS-settlement greater slowly and offer less effective
contractions but over a longer period.
Tailored for cardio respiration to avoid lactic acid build up.
Tailored for staying power work.
Has plenty of myoglobin, rich bloody deliver and lots of mitochondria.
Describe the additives of a reflex arc and provide an example. - ANS-1. Stimulus- warmth
Acetylation of DNA - ANS-acetyl businesses brought to histones, so DNA is much less tightly
wound spherical it, making it less difficult for RNA polymerase and transcriptional factors to
bind, so transcription can arise.
Allopatric speciation - ANS-When populations of a species emerge as geographically
remoted. Gene glide among them ceases (reproductive isolation). The new environment will
trigger a alternate inside the gene pool because of natural choice imposed on them.
If the populations are especially small, they may revel in a founder impact.
Selection and genetic flow will act differently on these two specific genetic backgrounds,
developing genetic variations between the two new species.
Codominance - ANS-happens where heterozygote has a phenotype this is unique from each
homozygotes.
Neither allele is dominant over the opposite; they both make a contribution similarly to the
phenotype.
Define biomass - ANS-the whole mass of organisms in a given area
define network. - ANS-all of the populations of different species dwelling and interacting in a
selected place on the identical time.
Outline area of interest. - ANS-the position and function a species has in its environment; the
way it meets its desires for food and refuge, the way it survives, and how it reproduces. A
species' niche consists of all of its interactions with the biotic and abiotic elements of its
environment.
Define populace. - ANS-a collection of people of one species that occupy the same habitat
on the identical time and are potentially able to interbreed.
Describe and explain the position of hormones in osmoregulation. - ANS-1.Osmoreceptors in
hypothalamus locate fall in water potential as they begin to decrease, inflicting hypothalamus
to supply ADH.
2. ADH goes to posterior pituitary gland, in which it is secreted into capillaries.
3. ADH goes from blood to kidneys, where it binds to receptors at the cells of of distil
convoluted tubule and amassing duct.
Four. This activates phosphorylase enzyme.
5. This reasons vesicles, which include water channel proteins, to fuse with cell surface
membrane. As a result, making it greater permeable to water.
6. Additionally increases permeability of gathering duct to urea so it passes out and lowers
water ability, so more water can pass out via osmosis.
Describe and explain the steps in the light structured reaction of photosynthesis - ANS-1.
Photoionisation: mild reaches chlorophyll in PSII, that is absorbed by an electron, which
becomes excited and movements to a higher power degree.
2. The electron passes to a provider protein in the thylakoid membrane, and is surpassed
down a sequence of carrier molecules referred to as an electron switch chain.
Three. As the electron actions down, strength is lost from the electron and is released as
ATP.
4. The lack of electron from PSII is 'refilled' by an electron produced by using photolysis,
which additionally produces hydrogen and oxygen.
, Five. The misplaced electron reaches PSI, which absorbs light power and boosts every other
electron to a better strength stage (excitation).
6. This electron also is going down an electron delivery chain.
7. This reaches the very last electron acceptor that's a proton. They combine to shape H and
decrease NADP to NADPH.
Describe and give an explanation for the stairs within the light unbiased reaction pf
photosynthesis. - ANS-1. CO2 diffuses into stroma and combines with ribulose bisphosphate
(RuBP) using the enzyme rubisco.
2. This bureaucracy an risky 6 carbon molecule, which splits into 2 3 carbon molecules,
glyercate-three-phosphate (G3P) .
3. G3P is decreased by means of NADPH to triose-phosphate (TP), that's aided through
ATP for energy.
4. TP can be converted into beneficial natural materials.
5. TP also can be reformed into RuBP using ATP.
Describe rapid twitch fibres - ANS-agreement extra rapidly and more effective however over
a shorter period of time.
Tailored for extreme exercising
have thicker and more severa myosin filament, have more glycogen, have more enzymes to
carry out anaerobic breathing, has phosphocreatine.
Describe glycolysis in respiratory. Provide internet formation. - ANS-1. Glucose is
transformed into phosphorylated glucose by means of 2ATP. This makes it very reactive, so
it splits into 2 triose phosphate (TP).
2. 2TP is then oxidised by using 2NAD and four ATP is formed to shape pyruvate.
Three. NET: 2ATP, 2Pyruvate, 2NADH, 2H+
describe krebs cycle in respiratory. Deliver net formation. - ANS-1. Acetyl co-enzyme A
combines with four carbon molecule (oxaloacetate) to shape 6 carbon citric acid.
2. CO2 is misplaced (decarboxylation), molecule is oxidised by means of NAD and ATP is
produce. This bureaucracy 5 carbon compound.
3. It's far oxidised by means of 2NADH and FAD, and is decarboxylated.
4. This forms four carbon molecule again.
Describe hyperlinks reaction in respiratory. Provide internet formation. - ANS-1. Pyruvate
diffuses into the matrix of mitochondria.
2. Pyruvate is oxidised via NAD. CO2 is misplaced. This bureaucracy acetate.
Three. Acetate and co-enzyme A combine to form acetyl co-enzyme A.
Four. NET: CO2, reduced NAD, acetyl co-enzyme A
describe oxidative phosphorylation in respiratory. - ANS-1. Reduced coenzyme passes its H
to a carrier protein inside the ETC. This splits right into a proton and electron.
2. The protons skip thru the space among internal and outer mitochondrial membrane.
Three. Electrons bypass via proteins on ETC.
Four. Protons go back back via ATP synthase in the membrane, generating ATP.
5. The protons and electrons recombine to shape H, which mixes with O to form water.
6. Oxygen is the last electron acceptor in the ETC.
Describe gradual twitch fibres - ANS-settlement greater slowly and offer less effective
contractions but over a longer period.
Tailored for cardio respiration to avoid lactic acid build up.
Tailored for staying power work.
Has plenty of myoglobin, rich bloody deliver and lots of mitochondria.
Describe the additives of a reflex arc and provide an example. - ANS-1. Stimulus- warmth
