AQA GCSE Biology - Paper 2 NEWEST 2025 ACTUAL EXAM COMPLETE 180
QUESTIONS AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS) |100%
GUARANTEED PASS!!
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.
QUESTIONS AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS) |100%
GUARANTEED PASS!!
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.
