OCR A Level Biology A
OCR A Level Biology A Communication and Homeostasis Exam Questions
Free OCR A Level Biology A exam questions on Communication and Homeostasis, with mark schemes. Covers the need for communication, cell signalling, homeostasis, negative feedback and thermoregulation.
Communication and Homeostasis exam questions
1 question pack of real past exam questions with its mark scheme. Answer every question without notes, then mark your answers line by line against the mark scheme.
StemUp mark scheme flashcards
OCR A Level Biology A H420 Flashcards (Anki & Quizlet)
Every answer is written in mark scheme wording, so you learn exactly what examiners give marks for. Use them on Anki or Quizlet, then test yourself with the questions on this page.
From £10.99View flashcards
About OCR A Level Biology A Communication and Homeostasis
This topic introduces how organisms keep internal conditions stable.
What you need to know
- Cell signalling Communication between cells using neurones and hormones.
- Homeostasis Maintaining a constant internal environment.
- Feedback Negative feedback restores the norm; positive feedback amplifies change.
- Thermoregulation Ectotherms and endotherms; vasodilation, sweating and shivering.
Common mistakes in Communication and Homeostasis
- Saying blood vessels move to the skin surface.
- Confusing ectotherms and endotherms.
- Giving positive feedback examples as homeostatic.
Try three Communication and Homeostasis exam-style questions
1. Define negative feedback. (1 mark)
Show the mark scheme answer
A change triggers a response that reverses the change.
2. Explain how vasoconstriction reduces heat loss. (2 marks)
Show the mark scheme answer
Arterioles near the skin narrow (1), so less blood flows near the surface and less heat radiates (1).
3. Give one example of positive feedback. (1 mark)
Show the mark scheme answer
Oxytocin release during childbirth.
Communication and Homeostasis FAQs
What does this topic cover?
Cell signalling, homeostasis and thermoregulation.
How do ectotherms control temperature?
Mainly by behaviour, such as basking.
What detects temperature changes?
Thermoreceptors and the hypothalamus.
Revise this topic with flashcards: OCR A Level Biology A H420 Flashcards, with mark scheme answers for Anki and Quizlet.
