8464 B 1H BIOLOGY PAPER 1H ACTUAL EXAM
PAPER 2026 QUESTIONS WITH SOLUTIONS
GRADED A+
◉ 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.