Master GCSE Biology

MS1:

- Stimulus: A change in the environment that triggers a response (1)

- Example: Light, sound, temperature, etc. (1)

MS2:

- Signal (electrical impulse) travels along the axon towards the synapse (1)

- Neurotransmitter is released from the presynaptic neurone (1)

- Neurotransmitter diffuses across the synaptic cleft and binds to receptors on the postsynaptic neurone (1)

MS3:

- When blood glucose levels rise, the pancreas releases insulin (1)

- Insulin promotes glucose uptake by body cells (1)

- When blood glucose levels fall, the pancreas releases glucagon (1)

- Glucagon stimulates the liver to convert stored glycogen to glucose (1)

MS4:

- Reduces urine output by increasing water reabsorption in the kidneys (1)

- Maintains water balance in the body (1)

MS5:

- Auxins: Promote cell elongation and root growth (1)

- Gibberellins: Promote stem elongation and seed germination (1)

- Both are plant hormones that regulate plant development and growth (1)

MS6:

- Stimulus detected by receptor (1)

- Sensory neurone transmits signal from receptor to central nervous system (brain/spinal cord) (1)

- Central nervous system processes signal and sends motor response to effector (muscle/gland) (1)

- Effector carries out the response (1)

MS7:

- Adrenal gland (1)

- Adrenaline (epinephrine) prepares the body for the 'fight or flight' response (1)

MS8:

- Insulin: Lowers blood glucose levels (1)

- Glucagon: Raises blood glucose levels (1)

- Their opposing actions help maintain glucose homeostasis (1)

MS9:

- Thyroxine is produced by the thyroid gland (1)

- Increases metabolic rate and heat production (1)

- Regulates body temperature and energy levels (1)

- Influences growth and development (1)

MS10:

- Synapse: A junction between two neurones (1)

- Located at the end of the axon of the presynaptic neurone (1)