Master GCSE Biology

MS1:

- Stimulus: Any change in the internal or external environment that can trigger a response in an organism (1 mark)

- Example: Change in temperature, light intensity, or presence of a chemical (1 mark)

MS2:

- Receptors detect and respond to specific stimuli (1 mark)

- They convert stimuli into electrical signals (nerve impulses) or chemical signals (hormones) (1 mark)

MS3:

- Neurons have a cell body, dendrites (receive signals), and an axon (transmits signals) (1 mark)

- Electrical signals are generated in the cell body and travel along the axon (1 mark)

- Neurotransmitters are released from the axon to transmit signals across synapses (1 mark)

MS4:

- Insulin (1 mark)

MS5:

- Glucagon raises blood glucose levels (1 mark)

- Secreted by the pancreas when blood glucose levels drop (1 mark)

MS6:

- Stimulus: Change in temperature (1 mark)

- Receptor: Temperature receptors in the skin (1 mark)

- Effector: Muscles (1 mark)

- Voluntary or involuntary response: Shivering or sweating (1 mark)

MS7:

- Adrenaline (1 mark)

MS8:

- Auxins stimulate cell elongation (1 mark)

- They help regulate phototropism and gravitropism (1 mark)

MS9:

- Insulin lowers blood sugar levels (1 mark)

- Glucagon raises blood sugar levels (1 mark)

- These hormones are secreted by the pancreas (1 mark)

MS10:

- Thyroxine (1 mark)