AQA a level biology paper 3 2025Questions And
Answers 2025/2026
explain binary fission in bacteria - CORRECT ANSWER-the circular DNA molecule
gets replicated so therefore the plasmids replicate, then the cytoplasm divides
equally producing two genetically identical daughter cells
% increase in number of bacteria in 20 degrees versus 24 degrees celsius -
CORRECT ANSWER-10^5.2-10^4.1 divided by 10^4.1 multiplied by 100=1159%
BD is a drug that inhibits ATP synthase in myobacteria by stopping hydrogen ions
movement. Explain how BD kills these bacteria. - CORRECT ANSWER-No protons
will be able to move through the ATP synthase meaning there will be no energy to
add inorganic phosphate to ADP, no ATP for metabolic processes.
Table 1 shows for statements and the names of four parts of a nephron- tick the
true statements for each part. - CORRECT ANSWER-ADH receptors- distal
convoluted tube and collecting duct. Water can be absorbed from filtrate-
proximal convoluted tubule, distal convoluted tubule and collecting duct. Blood is
under high pressure- glomerulus. Glucose is absorbed from filtrate- proximal
convoluted tubule.
Why is protein not present in urine? - CORRECT ANSWER-Plasma proteins are too
large to filter through the basement membrane.
, Evaluation question. - CORRECT ANSWER-Small sample size, only done in rats not
humans, only two quantities, not a long time HOWEVER statistical test was
carried out showing that results were significant, rats and humans are both
mammals.
How many different genera of beetles are used in information provided. -
CORRECT ANSWER-2
Suggest two reasons why the first sample of beetles was captured during the
second week of august - CORRECT ANSWER-Beetles have enough time to emerge
from soil, to allow beetles to randomly distribute .
Why beetles have to be identified before being marked - CORRECT ANSWER-all 3
beetles are green.
Use the table provided to estimate population size of C. graminis - CORRECT
ANSWER-248+124=372. 405X372 divided by 124=1215
State two precautions they would've taken each year to obtain comparable data -
CORRECT ANSWER-collect samples at same time of year, make sure marking isn't
toxic.
general structure of an amino acid - CORRECT ANSWER-
Answers 2025/2026
explain binary fission in bacteria - CORRECT ANSWER-the circular DNA molecule
gets replicated so therefore the plasmids replicate, then the cytoplasm divides
equally producing two genetically identical daughter cells
% increase in number of bacteria in 20 degrees versus 24 degrees celsius -
CORRECT ANSWER-10^5.2-10^4.1 divided by 10^4.1 multiplied by 100=1159%
BD is a drug that inhibits ATP synthase in myobacteria by stopping hydrogen ions
movement. Explain how BD kills these bacteria. - CORRECT ANSWER-No protons
will be able to move through the ATP synthase meaning there will be no energy to
add inorganic phosphate to ADP, no ATP for metabolic processes.
Table 1 shows for statements and the names of four parts of a nephron- tick the
true statements for each part. - CORRECT ANSWER-ADH receptors- distal
convoluted tube and collecting duct. Water can be absorbed from filtrate-
proximal convoluted tubule, distal convoluted tubule and collecting duct. Blood is
under high pressure- glomerulus. Glucose is absorbed from filtrate- proximal
convoluted tubule.
Why is protein not present in urine? - CORRECT ANSWER-Plasma proteins are too
large to filter through the basement membrane.
, Evaluation question. - CORRECT ANSWER-Small sample size, only done in rats not
humans, only two quantities, not a long time HOWEVER statistical test was
carried out showing that results were significant, rats and humans are both
mammals.
How many different genera of beetles are used in information provided. -
CORRECT ANSWER-2
Suggest two reasons why the first sample of beetles was captured during the
second week of august - CORRECT ANSWER-Beetles have enough time to emerge
from soil, to allow beetles to randomly distribute .
Why beetles have to be identified before being marked - CORRECT ANSWER-all 3
beetles are green.
Use the table provided to estimate population size of C. graminis - CORRECT
ANSWER-248+124=372. 405X372 divided by 124=1215
State two precautions they would've taken each year to obtain comparable data -
CORRECT ANSWER-collect samples at same time of year, make sure marking isn't
toxic.
general structure of an amino acid - CORRECT ANSWER-
