AQA A LEVEL BIOLOGY PAPER 2 ACCURATE QUESTIONS AND
ANSWERS (VERIFIED) 2025
air spaces between them = rapid diffusion, long and narrow and are packed with chloroplast the thin
tissue of the leaf allows light to reach mesophyll - ANS-Name three advantages of mesophyll in the leaf
stroma in the fluid filled matrix - ANS-where does the LIR occur?
100 stacked discs of thylakoids - ANS-what is the grana?
chlorophyll absorbs light energy, excite electrons, move along carriers etc releasing energy, used to join
ADP and pi to form ATP, photolysis of water produces protons electrons oxygen, NADP reduced by
electrons - ANS-describe the light dependent reaction starting with Photolysis
electron is oxidised that reduces NADP, carries out series of redox reactions along the electron transport
chain that is then accepted by oxygen that is the terminal electron receptor which oxidises NADPH back
to NADP - ANS-describe the electron transport chain
contain both DNA and RNA so proteins can be manufactured quickly, thylakoid membrane has a large SA
for rapid DF and a network of proteins in the Grana to maximise the absorbance of light - ANS-name
three advantages of the structure of a chloraplast
CO2 combines 5 carbon ribulose-bi-phosphate to make 6 carbon molecule that is then catalysed by
rubisco to create two 3 phosphate glycerate molecules that are then reduced via NADP and energy from
ATP from LDR to triose phosphate that will eventually turn into glucose, NADP reformed and goes back
to LDR - ANS-describe the process of the LIR
phosphorylated glucose is broken down in two 3 carbon molecules called pyruvate (happens in the
matrix mitochondria - ANS-what is glycolysis and where does it happen?
, pyruvate is decarboxylated and dehydrogenated to acetate NAD is reduced - ANS-what happens in the
link reaction after Glycolysis?
acetyl coenzyme A combines with oxaloacetate to form citrate which is decarboxylated and
dehydrogenated to form 5 carbon molecule which is then dehydrogenated and decarboxylated to form
4 carbon ATP made by substrate-level phosphorylation and FAD is reduced, oxalacetate is then
regenerated to restart the cycle - ANS-what happens in the Krebs Cycle after the link reaction?
H+ from oxidized reduced NAD and FAD, splits into p and e travels down electron transport chain via
oxidation-reduction reactions losing energy each carrier used pump p from matrix into intermembrane
space creating high concentration forming electrochemical gradient move down into matrix by ATP
synthase drives synthesis ATP chemiosmosis, Matriz end transport chain p,e, and o combine form water.
o final electron acceptor. - ANS-what is oxidative phosphorylation?
hydrolysed to glycerol that is phosphorylated into into triose phosphate that becomes glucose and thus
glycolysis can occur - ANS-how does the respiration of lipids occur?
where no oxygen is available to accept the H+ ion and so reduced NAD builds up and cannot take
anymore H+ from Glyolysis thus pyruvate is now reduced and produces lactate and oxdidised NAD and
produces ethanol in plants - ANS-what is anaerobic respiration?
the dry weight of the total mass of living material in a specific area at a given time - ANS-what is
biomass?
gross primary production - respiratory losses = the chemical energy left - ANS-what is the calculation for
net primary production? and what is it?
total chemical plant biomass - ANS-what is gross primary production?
net production = chemical energy of ingested plants - (energy lost in faeces + energy lost in respiration) -
ANS-what is the calculation for net production?
ANSWERS (VERIFIED) 2025
air spaces between them = rapid diffusion, long and narrow and are packed with chloroplast the thin
tissue of the leaf allows light to reach mesophyll - ANS-Name three advantages of mesophyll in the leaf
stroma in the fluid filled matrix - ANS-where does the LIR occur?
100 stacked discs of thylakoids - ANS-what is the grana?
chlorophyll absorbs light energy, excite electrons, move along carriers etc releasing energy, used to join
ADP and pi to form ATP, photolysis of water produces protons electrons oxygen, NADP reduced by
electrons - ANS-describe the light dependent reaction starting with Photolysis
electron is oxidised that reduces NADP, carries out series of redox reactions along the electron transport
chain that is then accepted by oxygen that is the terminal electron receptor which oxidises NADPH back
to NADP - ANS-describe the electron transport chain
contain both DNA and RNA so proteins can be manufactured quickly, thylakoid membrane has a large SA
for rapid DF and a network of proteins in the Grana to maximise the absorbance of light - ANS-name
three advantages of the structure of a chloraplast
CO2 combines 5 carbon ribulose-bi-phosphate to make 6 carbon molecule that is then catalysed by
rubisco to create two 3 phosphate glycerate molecules that are then reduced via NADP and energy from
ATP from LDR to triose phosphate that will eventually turn into glucose, NADP reformed and goes back
to LDR - ANS-describe the process of the LIR
phosphorylated glucose is broken down in two 3 carbon molecules called pyruvate (happens in the
matrix mitochondria - ANS-what is glycolysis and where does it happen?
, pyruvate is decarboxylated and dehydrogenated to acetate NAD is reduced - ANS-what happens in the
link reaction after Glycolysis?
acetyl coenzyme A combines with oxaloacetate to form citrate which is decarboxylated and
dehydrogenated to form 5 carbon molecule which is then dehydrogenated and decarboxylated to form
4 carbon ATP made by substrate-level phosphorylation and FAD is reduced, oxalacetate is then
regenerated to restart the cycle - ANS-what happens in the Krebs Cycle after the link reaction?
H+ from oxidized reduced NAD and FAD, splits into p and e travels down electron transport chain via
oxidation-reduction reactions losing energy each carrier used pump p from matrix into intermembrane
space creating high concentration forming electrochemical gradient move down into matrix by ATP
synthase drives synthesis ATP chemiosmosis, Matriz end transport chain p,e, and o combine form water.
o final electron acceptor. - ANS-what is oxidative phosphorylation?
hydrolysed to glycerol that is phosphorylated into into triose phosphate that becomes glucose and thus
glycolysis can occur - ANS-how does the respiration of lipids occur?
where no oxygen is available to accept the H+ ion and so reduced NAD builds up and cannot take
anymore H+ from Glyolysis thus pyruvate is now reduced and produces lactate and oxdidised NAD and
produces ethanol in plants - ANS-what is anaerobic respiration?
the dry weight of the total mass of living material in a specific area at a given time - ANS-what is
biomass?
gross primary production - respiratory losses = the chemical energy left - ANS-what is the calculation for
net primary production? and what is it?
total chemical plant biomass - ANS-what is gross primary production?
net production = chemical energy of ingested plants - (energy lost in faeces + energy lost in respiration) -
ANS-what is the calculation for net production?
