GCSE AQA TRIPLE BIOLOGY HIGHER TIER
PAPER 2 QUESTIONS AND ANSWERS WELL
ILLUSTRATED.
1. Homeostasis: 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.
2. Negative Feedback: 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.
3. The Thermoregulatory Centre: This is in the brain and it monitors and controls
body temperature, blood temperature via impulses from temperature receptors.
4. Effects when Body Temperature is too High: - Vasodilation.
- Swear more.
- Transfer of energy form the skin to the environment.
5. Effects when Body Temperature is too Low: - Vasoconstriction
- Stop sweating
- Piloerection
- Shiver
6. The Nervous System: This enables humans to react to their surroundings and
coordinate their behaviour. It stimulates a reflex arc.
7. Types of Neurones: Sensory Neurone, Motor Neurone, Relay Neurone.
8. Reflex Arc: 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
9. Synapse: The connection between neurones. When an electrical impulse reach-
es this, a chemical is released that diffused across the gap. This causes an electrical
impulse to be generated in the second one.
10. Human Reaction Time Required Practical: 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.
11. Parts of the brain: - Medulla
- Cerebellum
- Cerebral Cortex
PAPER 2 QUESTIONS AND ANSWERS WELL
ILLUSTRATED.
1. Homeostasis: 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.
2. Negative Feedback: 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.
3. The Thermoregulatory Centre: This is in the brain and it monitors and controls
body temperature, blood temperature via impulses from temperature receptors.
4. Effects when Body Temperature is too High: - Vasodilation.
- Swear more.
- Transfer of energy form the skin to the environment.
5. Effects when Body Temperature is too Low: - Vasoconstriction
- Stop sweating
- Piloerection
- Shiver
6. The Nervous System: This enables humans to react to their surroundings and
coordinate their behaviour. It stimulates a reflex arc.
7. Types of Neurones: Sensory Neurone, Motor Neurone, Relay Neurone.
8. Reflex Arc: 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
9. Synapse: The connection between neurones. When an electrical impulse reach-
es this, a chemical is released that diffused across the gap. This causes an electrical
impulse to be generated in the second one.
10. Human Reaction Time Required Practical: 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.
11. Parts of the brain: - Medulla
- Cerebellum
- Cerebral Cortex
