UNIT OVERVIEW

This revision unit covers how humans and plants detect and respond to changes around them. You will revise:

• The human nervous system (how nerve signals travel)
• The human endocrine system (how hormones control the body)
• Homeostasis (how the body stays balanced inside)
• Plant hormones and tropisms (how plants grow toward light and respond to gravity)

These topics are heavily examined. This unit will help you understand the key ideas, avoid common mistakes, and practise CAPS-style questions.