Detailed revision notes for ‘Organisms Respond to Changes in their Internal and External Environments’ unit of the AQA Biology Specification.

Specifically, it covers:

• Stimuli, both internal and external, and how they lead to a response
• Survival and Response
• Receptors
• Control of Heart Rate
• Nerve Coordination
• Nerve Impulses
• Synaptic Transmission
• How Skeletal Muscles are stimulated to contract by nerves and how skeletal muscles act as effectors
• Principles of Homeostasis and Negative Feedback
• Control of Blood Glucose Concentration
• Control of Blood Water Potential

Several Practice Exam Questions are provided at the end of the revision booklet to apply what you have learnt