More guides on this topic

• Coordination and control - The nervous system - OCR Gateway
• Coordination and control - The endocrine system - OCR Gateway
• Plant hormones - OCR Gateway
• Sample exam questions - organism level systems - OCR Gateway

Related links

• Biology: Exam-style questions
• Biology revision resources
• Bitesize revision podcasts
• Personalise your Bitesize!
• Jobs that use Biology
• Save My Exams Subscription
• Quizlet
• Tassomai Subscription
• Headsqueeze
• Revision Buddies Subscription