AQA GCSE Biology Paper 2 Exam |
Questions And Answers| Latest Exam
2026-2027 |
What is homeostasis? -ANSWER The maintenance of a constant internal environment.
What is a stimulus? -ANSWER A change in your environment than requires a response.
e.g Light, sound, touch, pressure, pain, chemical or temperature.
What do the receptors do? -ANSWER Detect the stimulus or change in environment.
What happens after the receptors? -ANSWER Receptors send messages to the CNS via
the sensory neurone.
What makes up the central nervous system? -ANSWER The brain or spinal cord
What is an effector? -ANSWER Muscles or glands that bring about a response.
What do the muscles and glands do in response to stimuli? -ANSWER Muscles contract
and glands secrete chemical substances(hormones).
What is a sensory neurone? -ANSWER A neurone that carry information from the
receptors to the CNS.
What is a relay neurone? -ANSWER Neurones that carry impulses from the sensory
neurone to the motor neurone.
What is a motor neurone? -ANSWER Neurones that carry information from the CNS to
the effectors.
What is the nervous system? -ANSWER It is a system that allows you to react to your
surroundings.
How do signals travel across a synapse? -ANSWER The chemical or neurotransmitter
diffuses across the synapse and binds to a complementary receptor on the neurone
(postsynaptic). This causes an electrical impulse to travel down the next neurone.
What is a synapse? -ANSWER A gap between two neurones.
What is the thermoregulatory centre of the brain? -ANSWER Near the hypothalamus,
monitors the temperature of blood.
,Describe the stages in a reflex arc. -ANSWER Stimulus->Receptor->sensory neurone-
>CNS (relay neurone) -> motor neurone -> effector -> response
Name responses that reduce body temperature. -ANSWER Hairs lie flat, sweat and blood
vessels get wider(vasodilation)
What happens during vasodilation? -ANSWER The blood vessels supplying the skin
dilate (widen). This helps to transfer energy to the environment.
Name responses that increase body temperature. -ANSWER Hairs stand up, no sweat,
shivering and blood vessels constrict(vasoconstriction)
What happens during vasoconstriction? -ANSWER The blood vessels supplying the skin
constrict to close off the skins blood supply.
What is the body's core temp? -ANSWER 37 degrees Celsius
What are hormones? -ANSWER Chemical messengers that travel in the blood to target
organs.
Compare and Contrast the endocrine (hormone) system and the nervous system. -
ANSWER Nervous is faster acting than the endocrine system.
Hormones have longer lasting effects compared to electrical impulses. Nerves act on a
very specific area whereas hormones act more general.
What does the thyroid gland do? -ANSWER Produces thyroxine which is involved in
regulating metabolism.
What do the adrenal glands do? -ANSWER Produce adrenaline which is used to prepare
the body for fight or flight.
What is the role of the pancreas? -ANSWER Produces glucagon and insulin which are
involved in regulating glucose levels in the blood.
Name the hormone that is released if blood sugar is too high. -ANSWER Insulin
What does insulin do? -ANSWER It makes the liver convert glucose into glycogen. This
causes blood glucose levels to decrease.
Name the hormone that is released if blood sugar is too low. -ANSWER Glucagon
What does glucagon do? HINT GLU-COSE-GONE -ANSWER It makes the liver convert
glycogen to glucose. This causes the blood glucose level to increase.
What is type I diabetes? -ANSWER When the pancreas produces little or no insulin.
, What is type II diabetes? -ANSWER When a person becomes resistant to their own
insulin. Being overweight can increase your chances of type II diabetes.
How can type I diabetes be treated? -ANSWER Insulin injections, limiting intake of foods
rich is simple carbohydrates e.g. sugars and regular exercise.
How can type II diabetes be treated? -ANSWER It can be controlled by eating a
carbohydrate controlled diet and getting regular exercise.
What is the role of the kidneys. -ANSWER Kidneys make urine by taking unwanted waste
products out of your blood. They are involved in selective reabsorption.
Name three things that are re-absorbed by the kidneys into the blood. -ANSWER
Glucose, water and ions.
Name three things that are removed from the body in the urine. -ANSWER Urea, water
and ions.
What is deamination? -ANSWER Proteins (excess amino acids) cannot be stored by the
body. Excess amino acids are converted to fats and carbohydrates. This occurs in the
liver.
What is produced as a waste product of deamination? -ANSWER Ammonia is produced
as a waste product. Ammonia is toxic so it is converted into urea in the liver.
What hormone controls the amount of water absorbed by the kidneys? -ANSWER ADH
What happens when the concentration of water in the blood is too low. I.e. the Blood is
MORE concentrated. -ANSWER Receptors in the hypothalamus detects the water
content is too low. The coordinator in the brain receives the information and coordinates
a response. The pituitary gland produces MORE (Anti-diuretic hormone) ADH, which
makes the kidney tubule MORE permeable. This means that MORE water is
reabsorbed into the bloodstream. The kidneys produce a small volume of concentrated
urine.
What happens when the concentration of water in the blood is too high. I.e. the Blood is
dilute/LESS concentrated. -ANSWER Receptors in the hypothalamus detects the water
content is too high. The coordinator in the brain receives the information and
coordinates a response. The pituitary gland produced LESS ADH, which makes the
kidney tubule LESS permeable. This means that LESS water is reabsorbed into the
bloodstream. The kidneys produce a large volume of dilute urine.
How does a dialysis machine work? -ANSWER In a dialysis machine the patients blood
flows between a partially permeable membrane surrounded by dialysis fluid. The
dialysis fluid contains the same concentration of dissolved ions and glucose as healthy
Questions And Answers| Latest Exam
2026-2027 |
What is homeostasis? -ANSWER The maintenance of a constant internal environment.
What is a stimulus? -ANSWER A change in your environment than requires a response.
e.g Light, sound, touch, pressure, pain, chemical or temperature.
What do the receptors do? -ANSWER Detect the stimulus or change in environment.
What happens after the receptors? -ANSWER Receptors send messages to the CNS via
the sensory neurone.
What makes up the central nervous system? -ANSWER The brain or spinal cord
What is an effector? -ANSWER Muscles or glands that bring about a response.
What do the muscles and glands do in response to stimuli? -ANSWER Muscles contract
and glands secrete chemical substances(hormones).
What is a sensory neurone? -ANSWER A neurone that carry information from the
receptors to the CNS.
What is a relay neurone? -ANSWER Neurones that carry impulses from the sensory
neurone to the motor neurone.
What is a motor neurone? -ANSWER Neurones that carry information from the CNS to
the effectors.
What is the nervous system? -ANSWER It is a system that allows you to react to your
surroundings.
How do signals travel across a synapse? -ANSWER The chemical or neurotransmitter
diffuses across the synapse and binds to a complementary receptor on the neurone
(postsynaptic). This causes an electrical impulse to travel down the next neurone.
What is a synapse? -ANSWER A gap between two neurones.
What is the thermoregulatory centre of the brain? -ANSWER Near the hypothalamus,
monitors the temperature of blood.
,Describe the stages in a reflex arc. -ANSWER Stimulus->Receptor->sensory neurone-
>CNS (relay neurone) -> motor neurone -> effector -> response
Name responses that reduce body temperature. -ANSWER Hairs lie flat, sweat and blood
vessels get wider(vasodilation)
What happens during vasodilation? -ANSWER The blood vessels supplying the skin
dilate (widen). This helps to transfer energy to the environment.
Name responses that increase body temperature. -ANSWER Hairs stand up, no sweat,
shivering and blood vessels constrict(vasoconstriction)
What happens during vasoconstriction? -ANSWER The blood vessels supplying the skin
constrict to close off the skins blood supply.
What is the body's core temp? -ANSWER 37 degrees Celsius
What are hormones? -ANSWER Chemical messengers that travel in the blood to target
organs.
Compare and Contrast the endocrine (hormone) system and the nervous system. -
ANSWER Nervous is faster acting than the endocrine system.
Hormones have longer lasting effects compared to electrical impulses. Nerves act on a
very specific area whereas hormones act more general.
What does the thyroid gland do? -ANSWER Produces thyroxine which is involved in
regulating metabolism.
What do the adrenal glands do? -ANSWER Produce adrenaline which is used to prepare
the body for fight or flight.
What is the role of the pancreas? -ANSWER Produces glucagon and insulin which are
involved in regulating glucose levels in the blood.
Name the hormone that is released if blood sugar is too high. -ANSWER Insulin
What does insulin do? -ANSWER It makes the liver convert glucose into glycogen. This
causes blood glucose levels to decrease.
Name the hormone that is released if blood sugar is too low. -ANSWER Glucagon
What does glucagon do? HINT GLU-COSE-GONE -ANSWER It makes the liver convert
glycogen to glucose. This causes the blood glucose level to increase.
What is type I diabetes? -ANSWER When the pancreas produces little or no insulin.
, What is type II diabetes? -ANSWER When a person becomes resistant to their own
insulin. Being overweight can increase your chances of type II diabetes.
How can type I diabetes be treated? -ANSWER Insulin injections, limiting intake of foods
rich is simple carbohydrates e.g. sugars and regular exercise.
How can type II diabetes be treated? -ANSWER It can be controlled by eating a
carbohydrate controlled diet and getting regular exercise.
What is the role of the kidneys. -ANSWER Kidneys make urine by taking unwanted waste
products out of your blood. They are involved in selective reabsorption.
Name three things that are re-absorbed by the kidneys into the blood. -ANSWER
Glucose, water and ions.
Name three things that are removed from the body in the urine. -ANSWER Urea, water
and ions.
What is deamination? -ANSWER Proteins (excess amino acids) cannot be stored by the
body. Excess amino acids are converted to fats and carbohydrates. This occurs in the
liver.
What is produced as a waste product of deamination? -ANSWER Ammonia is produced
as a waste product. Ammonia is toxic so it is converted into urea in the liver.
What hormone controls the amount of water absorbed by the kidneys? -ANSWER ADH
What happens when the concentration of water in the blood is too low. I.e. the Blood is
MORE concentrated. -ANSWER Receptors in the hypothalamus detects the water
content is too low. The coordinator in the brain receives the information and coordinates
a response. The pituitary gland produces MORE (Anti-diuretic hormone) ADH, which
makes the kidney tubule MORE permeable. This means that MORE water is
reabsorbed into the bloodstream. The kidneys produce a small volume of concentrated
urine.
What happens when the concentration of water in the blood is too high. I.e. the Blood is
dilute/LESS concentrated. -ANSWER Receptors in the hypothalamus detects the water
content is too high. The coordinator in the brain receives the information and
coordinates a response. The pituitary gland produced LESS ADH, which makes the
kidney tubule LESS permeable. This means that LESS water is reabsorbed into the
bloodstream. The kidneys produce a large volume of dilute urine.
How does a dialysis machine work? -ANSWER In a dialysis machine the patients blood
flows between a partially permeable membrane surrounded by dialysis fluid. The
dialysis fluid contains the same concentration of dissolved ions and glucose as healthy
