CoREs

•Describe the difference between an internal and external environment •Know what it means to be a regulator and a conformer •Homeostasis occurs in all living things, although varies depending on the species and is critical for their survival •Homeostasis is environment dependent •Know the role of the negative feedback response •Homeostasis can be disrupted by events such as disease and trauma •The endocrine and nervous system are the main homeostasis regulators in humans •All body systems are effectors of homeostasis •To understand human and plant regulation processes •To know the causes of an unstable internal environment are: 1.Nutrient concentration 2.Temperature 3.Water levels (dehydration) 4.Ion Concentration 5.pH 6.volume and pressure 7.Oxygen and Carbon Dioxide concentration 8.Red blood cells || Organisms respond to both external and internal signals.Detection of signals such as through the senses allows the organism to respond in an appropriate fashion. Similarly, detection of internal signals (e.g. low blood glucose) can result in an internal response. These systems are important in maintaining homeostasis.
 * **VCE Unit 3** || **Homeostasis** || **Detecting, transmission** **and responding** || **Self &****Non-self** ||
 * **What you intend the __students__ to learn about this idea. ** || •Homeostasis, keeping the cells at a stable internal environment

Responding involves two systems, the endocrine and the nervous systems.Signal transduction can occur through chemical means (endocrine - hormones and nervous - neurotransmitters) and through electrical impulse (nervous - action potential).

Specificity is a property of the signaling system and occurs through receptors for different chemical messengers which are located on cell membranes and within cells.

The immune system is an example of a highly specialised detection and response system. || To understand how the detection of self and non-self molecules occurs.

Understanding how antigens and membrane receptors work.

Physical and chemical barriers Immune response

Structure

Nonspecific/Specific

Disorders

Acquired immunity ||
 * **Why it is important for students to know this. ** || Homeostasis is crucial for the survival of all living things, and in regards to biology an understanding of homeostasis is needed to understand further concepts of immunity, cell denaturing and the effects an unstable environment has on an organism and its function and reproduction.

Also to understand that all organisms have a certain range that is ideal and anything outside their ideal is dangerous for health and life.

The importance of environmental effect on an organism, which can cause preventable side effects. || Organisms need to be able to respond to external stimuli to prevent damage to the organism (e.g. light shining on pupil, pain to fingers); can also respond to internal signals to maintain homeostasis.

Multiple systems are responsible for various effects (e.g. local vs. systemic effects). Knowledge of the different complimentary systems provides an understanding of how an organism is able to coordinate and regulate itself with great specificity, and allows for an understanding of various disorders that may arise from problems with such systems, as well as how to treat these problems.

Cells need to communicate to each other for organism to function with highly specialised cells that perform different tasks.

Receptors are the basis for cell-cell communication and most cellular processes that occur. ||  ||
 * **What else __you__ know about this idea (that you do not intend students to know yet). ** || * Homeostasis has a big impact on the self and non self detection of cells
 * The effects of denaturing a cell and the impact on its function
 * The role of homeostasis in evolution
 * The role of the nervous and endocrine systems in the balancing of homeostasis || Why do we have all the different signaling systems, instead of just one? [Different parts of nervous system, multiple signaling pathways, control of individual organs etc.]

How do we respond differently to very similar stimuli? [high level of specificity through multiple systems and receptors]

How does the body recognise only foreign material? [Segue into immunity and auto-immune diseases; this will be covered in immunity]. ||  ||
 * **Knowledge about students’ thinking ****/difficulties connected with teaching this idea ** || The textbook will describe homeostasis as a be all or end all circumstance

That we can use our knowledge of homeostasis to our benefit for health and living

Use a comparison of different species and organisms to identify the relationship between the regulatory processes and the environment e.g. mushrooms and beans || Understanding that every part of the human body is regulated might be a little intimidating at first (particularly for ‘everyday’ observations)

Confusion between electrical and chemical signals and in which systems they occur, there may also be confusion about the speed that signals are transmitted.

How are chemical signals not mixed up? Receptor specificity ||  ||
 * **Teaching procedures ****(and particular reasons for using these to engage with this idea). ** || **Mind map / Concept map**: Draw a concept map with “Homeostasis” as the centre point and have different words from this chapter and get the students to link the words to each other in relation to homeostasis.

**Crossword construction:** so students understand words and their definitions

**Flow chart**: Flow chart of the negative feedback response. Good visual activity.

**Name and Label**: Name and label each body system and how it remains stable (what makes it unstable). This is also a good visual activity.

**Practicals**: let the students get a visual understanding of the theory.

**Videos and websites:** Examples associated with homeostasis. These mix up the class.

**Chapter review/ summary questions**: Unit chosen textbook, Heinemann, Nelson or Nature of Biology all chapter 5. || **POE**: HR vs. exercise or iris dilation/contraction(understanding senses - how is information transmitted? segue into class discussion)

**Mapping:** out the systems (nervous, endocrine) against a model of the human body. Allows for some understanding of position and effect of the different systems. Trace a signal using the above systems to explain how a response is made

**Videos**: of receptor models and binding

**Modelling**: Get students to play with plasticine to develop models of receptor binding and explain properties of this phenomena (allows for kinaesthetic learners) - use for antibiotics (e.g. sulfa drugs).

In **Review** QuestionsJacaranda Nature of Biology Activity Manual pg. 56 - Nervous System (summary of nervous system as a topic) ||  ||
 * **Specific ways of ascertaining students’ understanding or confusion around this Idea ****(include likely range of responses). ** || ** Flow chart ** : to demonstrate the understanding of the process of negative feedback and the parts of the nervous or endocrine system it needs to go through. It’s also an opportunity for a visual demonstration rather than text.

**Crossword:** To develop an understanding of the terms and their meanings in regard to homeostasis.

**Practicals**: to put into a practice and observe the theory learnt.

**Chapter Review questions**: to highlight areas of understanding and areas of non understanding from the chapter for the students. || **Questioning the five senses**: what are they, how do they work – use to encounter misconceptions, students to annotate a map of the body to illustrate their understanding

**Quick quiz:** students to identify which systems are responsible for a variety of effects; e.g. lethargy after eating a sugar rich meal – endocrine, HR increase after startling

**Research task**: Ask students to choose a detection and response of their choice and detail the whole process (will require an understanding of multiple parts of the process and allows for individual interest to dictate what is studied)

**Modelling activity**: Of receptor binding. Asking students about what receptor types are present in certain cell types; often exemplars illustrate a single receptor type per cell which is a misconception || ** Flow chart ** : to demonstrate the understanding of the process of immunity and the detection of self and non – self molecules.


 * Crossword: ** To develop an understanding of the terms and their meanings in regard to immunity etc.


 * Practicals ** : to put into a practice and observe the theory learnt.


 * Chapter Review questions ** : to highlight areas of understanding and areas of non understanding from the chapter for the students. ||