Biology aqa A level common questions
Biology Aqa A Level Common Questions
Containing 87 Terms with Definitive
Solutions 2024-2025.
give two factors other than age and gender that would affect the concentration of
creatinine in the blood? - Answer: muscle/ body mass
ethnicity
, Biology aqa A level common questions
Explain how the cells of the collecting duct are able to absorb water from the
filtrate through the protein channels in their plasma membranes? - Answer: lower
w.p/ more negative inside tubule cells so h2o enters by osmosis
Suggest why diabetes insipidus is more common in males? - Answer: Bc males
only have X chromosome do not have Y chromosome single copy of recessive
allele will be expressed
A recessive allele which has harmful effects is able to reach a higher frequency in a
population than a harmful dominant allele. Explain how? - Answer: recessive
allele can be carried by individuals showing effects dominant alley always
expressed
organisms that are affected are more likely to reproduce therefore recessive
alleles are more likely to be passed on
In some forms of kidney disease, proteins from the blood plasma are found in the
urine. Which part of the nephron would have been damaged by the disease to
cause proteins from blood plasma to be present in the urine? Explain your answer
- Answer: glomerulus/ bowman’s capsule
basement membrane
proteins are large molecules cannot normally pass through filter
can only pass through if filter damaged
Describe the role of the hormone glucagon in the control of blood sugar
concentration? - Answer: glucagon binds to specific receptor on liver cells
, Biology aqa A level common questions
activation of enzymes in liver
hydrolysis of glycogen
F.D of glucose out of liver cells
increases blood glucose levels
Explain two ways in which the cells of the proximal convoluted tubule are adapted
for reabsorption.? - Answer: microvilli provide a large S.A for reabsorption
carrier proteins in membrane for A.T
channel proteins for F.D
many mitochondria for A.T and providing Atp
Explain the role of the loop of Henle in the absorption of water from the filtrate? -
Answer: in the ascending limb na+ ions actively transported
ascending limb impermeable to water
in descending limb na+ ions diffuse in
descending limb h2o moves out
low w.p (high conc of ions in medulla) the longer the loop, lower w.p in medulla
h2o leaves collecting duct by osmosis down w.p gradient
Explain the role of ADH in the production of concentrated urine? - Answer: when
w.p of blood too low it is detected by receptors in hypothalamus
pituitary secretes releases more ADH
ADH increases permeability opens channels for h2o in DCT
more h2o reabsorbed into blood by osmosis down w.p gradient
Biology Aqa A Level Common Questions
Containing 87 Terms with Definitive
Solutions 2024-2025.
give two factors other than age and gender that would affect the concentration of
creatinine in the blood? - Answer: muscle/ body mass
ethnicity
, Biology aqa A level common questions
Explain how the cells of the collecting duct are able to absorb water from the
filtrate through the protein channels in their plasma membranes? - Answer: lower
w.p/ more negative inside tubule cells so h2o enters by osmosis
Suggest why diabetes insipidus is more common in males? - Answer: Bc males
only have X chromosome do not have Y chromosome single copy of recessive
allele will be expressed
A recessive allele which has harmful effects is able to reach a higher frequency in a
population than a harmful dominant allele. Explain how? - Answer: recessive
allele can be carried by individuals showing effects dominant alley always
expressed
organisms that are affected are more likely to reproduce therefore recessive
alleles are more likely to be passed on
In some forms of kidney disease, proteins from the blood plasma are found in the
urine. Which part of the nephron would have been damaged by the disease to
cause proteins from blood plasma to be present in the urine? Explain your answer
- Answer: glomerulus/ bowman’s capsule
basement membrane
proteins are large molecules cannot normally pass through filter
can only pass through if filter damaged
Describe the role of the hormone glucagon in the control of blood sugar
concentration? - Answer: glucagon binds to specific receptor on liver cells
, Biology aqa A level common questions
activation of enzymes in liver
hydrolysis of glycogen
F.D of glucose out of liver cells
increases blood glucose levels
Explain two ways in which the cells of the proximal convoluted tubule are adapted
for reabsorption.? - Answer: microvilli provide a large S.A for reabsorption
carrier proteins in membrane for A.T
channel proteins for F.D
many mitochondria for A.T and providing Atp
Explain the role of the loop of Henle in the absorption of water from the filtrate? -
Answer: in the ascending limb na+ ions actively transported
ascending limb impermeable to water
in descending limb na+ ions diffuse in
descending limb h2o moves out
low w.p (high conc of ions in medulla) the longer the loop, lower w.p in medulla
h2o leaves collecting duct by osmosis down w.p gradient
Explain the role of ADH in the production of concentrated urine? - Answer: when
w.p of blood too low it is detected by receptors in hypothalamus
pituitary secretes releases more ADH
ADH increases permeability opens channels for h2o in DCT
more h2o reabsorbed into blood by osmosis down w.p gradient
