GCSE AQA Triple Biology Higher Tier
Paper 2 Exam Questions And Answers
Graded A+.
Homeostasis - Answer The regulation of the internal conditions of a cell or organism in response to
internal or external changes. E.g. the control of: blood glucose concentration, body temperature, water
and ion levels, etc.
Negative Feedback - Answer This is a type of control mechanism:
1) a receptor detects a change in a stimulus.
2) the coordination centre compares the stimulus to a set point.
3) an effector then produces a response to correct any difference from the set point.
The Thermoregulatory Centre - Answer This is in the brain and it monitors and controls body
temperature, blood temperature via impulses from temperature receptors.
Effects when Body Temperature is too High - Answer - Vasodilation.
- Swear more.
- Transfer of energy form the skin to the environment.
Effects when Body Temperature is too Low - Answer - Vasoconstriction
- Stop sweating
- Piloerection
- Shiver
The Nervous System - Answer This enables humans to react to their surroundings and coordinate their
behaviour. It stimulates a reflex arc.
Types of Neurones - Answer Sensory Neurone, Motor Neurone, Relay Neurone.
, Reflex Arc - Answer 1) the pain stimulus is detected by receptors.
2) impulses from the receptor pass along a sensory Neurone to the CNS.
3) an impulse then passed through a relay Neurone.
4) a motor neurone carries an impulse to the effector.
5) the effector (muscle or gland) responds
Synapse - Answer The connection between neurones. When an electrical impulse reaches this, a
chemical is released that diffused across the gap. This causes an electrical impulse to be generated in the
second one.
Human Reaction Time Required Practical - Answer 1) the experimenter holds a meter rule from the
end.
2) the subject had their finger and thumb a small distant apart either side of the ruler on the 50cm line.
3) the experimenter lets go of the ruler and the subject has to trap it.
4) the distance the ruler travels from the 50cm line is noted.
5) the experiment is repeated on the subjects that have just drunk coffee and the subjects that have not.
Parts of the brain - Answer - Medulla
- Cerebellum
- Cerebral Cortex
Medulla - Answer controls automatic actions such as heartbeat and breathing.
Cerebellum - Answer coordinates movement and balance
cerebral cortex - Answer responsible for consciousness, intelligence, memory and language.
Parts and Functions of the Eye - Answer - Retina - contains receptor cells that are sensitive to
brightness and colour of light.
Paper 2 Exam Questions And Answers
Graded A+.
Homeostasis - Answer The regulation of the internal conditions of a cell or organism in response to
internal or external changes. E.g. the control of: blood glucose concentration, body temperature, water
and ion levels, etc.
Negative Feedback - Answer This is a type of control mechanism:
1) a receptor detects a change in a stimulus.
2) the coordination centre compares the stimulus to a set point.
3) an effector then produces a response to correct any difference from the set point.
The Thermoregulatory Centre - Answer This is in the brain and it monitors and controls body
temperature, blood temperature via impulses from temperature receptors.
Effects when Body Temperature is too High - Answer - Vasodilation.
- Swear more.
- Transfer of energy form the skin to the environment.
Effects when Body Temperature is too Low - Answer - Vasoconstriction
- Stop sweating
- Piloerection
- Shiver
The Nervous System - Answer This enables humans to react to their surroundings and coordinate their
behaviour. It stimulates a reflex arc.
Types of Neurones - Answer Sensory Neurone, Motor Neurone, Relay Neurone.
, Reflex Arc - Answer 1) the pain stimulus is detected by receptors.
2) impulses from the receptor pass along a sensory Neurone to the CNS.
3) an impulse then passed through a relay Neurone.
4) a motor neurone carries an impulse to the effector.
5) the effector (muscle or gland) responds
Synapse - Answer The connection between neurones. When an electrical impulse reaches this, a
chemical is released that diffused across the gap. This causes an electrical impulse to be generated in the
second one.
Human Reaction Time Required Practical - Answer 1) the experimenter holds a meter rule from the
end.
2) the subject had their finger and thumb a small distant apart either side of the ruler on the 50cm line.
3) the experimenter lets go of the ruler and the subject has to trap it.
4) the distance the ruler travels from the 50cm line is noted.
5) the experiment is repeated on the subjects that have just drunk coffee and the subjects that have not.
Parts of the brain - Answer - Medulla
- Cerebellum
- Cerebral Cortex
Medulla - Answer controls automatic actions such as heartbeat and breathing.
Cerebellum - Answer coordinates movement and balance
cerebral cortex - Answer responsible for consciousness, intelligence, memory and language.
Parts and Functions of the Eye - Answer - Retina - contains receptor cells that are sensitive to
brightness and colour of light.
