1. Communication and Homeostasis
5.1.1 a-c
FLIP learning d

2. Spec (a) the need for communication systems in multicellular organisms
To include the need for animals and plants to respond to changes in the internal and external environment and to coordinate the activities of different organs.
(b) the communication between cells by cell signalling
To include signalling between adjacent cells and signalling between distant cells.
(c) the principles of homeostasis
To include the differences between receptors and effectors, and the differences between negative feedback and positive feedback.

3. Spec for Flipped
d) the physiological and behavioural responses involved in temperature control in ectotherms and endotherms.
To include, • endotherms – peripheral temperature receptors, the role of the hypothalamus and effectors in skin and muscles; behavioural responses • ectotherms – behavioural responses. An opportunity to monitor physiological functions in ectotherms and/or endotherms.

4. Learning Objective Success Criteria
Know about homeostasis
Outline the need for communication systems within multi-cellular organisms
Explain the principles of homeostasis

5. Starter Question
What conditions do you need to consider for efficient enzyme action?

6. Why do multicellular organisms need communication systems?
Internal Changes
External Changes
Co-ordinate activities of different organs

7. Cell Signalling The way in which cells can communicate with each other
Process in which one cell will release a chemical that is detected by another cell. The second cell will respond to the signal released by the first cell

8. Communication on a cellular level
Cell Signalling
Nervous System
Neurones & Synapses
Rapid
Hormonal System
Hormones carried in blood
Only recognised by target cells
Longer term responses

9. Task: Key terms: What do they mean?
Endocrine gland
Exocrine gland
Hormone
Target Tissue

10. Answers: Key terms: What do they mean?
Endocrine gland
Secretes hormones directly into the blood
Exocrine gland
Secretes molecules into a duct which carries them to where they are used
Hormone
Molecules released by endocrine glands directly into blood. Act as messengers carrying signal from endocrine gland to target tissue
Target Tissue
Possess specific receptor on their plasma membrane. Shape of receptor is complementary to the shape of the hormone molecule.

11. Negative Feedback Loop

12. Answer: Negative Feedback Loop
Optimum conditions
Effector reacts to reverse change
Change away from optimum
Communication system informs effector
Return to optimum
Receptor detects change

13. Freeze Screen!
Can students work out the stages from the songs?
Write answers on mini whiteboards

14. For teacher, don’t show to students!

15. Stimulus
Monitoring
Receptor
Control Centre
Effector
Response
Can you make a better memory prompt than I could?
List the songs for each step?
Change

16. Task
Using information on negative feedback complete the feedback loop for the example given

17. Positive Feedback Response to increase the original change
Destabilises the system
E.g. Dilation of the cervix during labour
Cervix stretches
Posterior pituitary gland secretes oxytocin
Causes uterine contractions
Stretches the cervix more
Causes the secretion of more oxytocin

18. Plenary
Past paper questions

19. Homeostasis Jan 12

20. Homeostasis Jan 12 Markscheme

21. Task: FLIP Learning
How do Ectotherms maintain a core body temperature?
Behavioural Responses
How do Endotherms maintain a core body temperature?
Physiological Responses
With reference to peripheral temperature receptors, hypothalamus & effectors in skin and muscles
Instruction sheet available to print

22. Spec for Flipped
d) the physiological and behavioural responses involved in temperature control in ectotherms and endotherms.
To include, • endotherms – peripheral temperature receptors, the role of the hypothalamus and effectors in skin and muscles; behavioural responses • ectotherms – behavioural responses. An opportunity to monitor physiological functions in ectotherms and/or endotherms.