GCSE BIOLOGY - AQA BIOLOGY PAPER 2 EXAM REVISION
QUESTIONS WITH VERIFIED SOLUTIONS LATEST 2025 UPDATE.
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.
QUESTIONS WITH VERIFIED SOLUTIONS LATEST 2025 UPDATE.
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.
