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Subject Summary: Part IA Physiology of Organisms

Physiology deals with how living organisms work. While often concentrating on the organ level (“how does the heart work?”), it covers life from the molecular level right up to the behaviour of the whole organism. In its applied aspects, physiology deals with the function and malfunction of parts of the human body with reference to health and disease (areas relating to medicine), how to improve crop yield (areas relating to plant sciences) as well as how organisms respond to challenging conditions (areas relating to ecology).  

We begin with an overview of physiological concepts, as applied to animal physiology. We look at how the basic organ systems such as the nervous, cardiovascular and respiratory systems work, how homeostasis is maintained and how animals respond to environmental challenges. Although mammalian physiology is taught in most detail, this is a comparative physiology course and so we also consider some of the different strategies found in other animals, such as fish and insects.

In the second term we move to plants. How do plants interact with the environment to obtain raw materials, and how these are processed and distributed? Control of growth and development is a major contributor to the survival and propagation of plants at all stages of the life cycle, and we explore the functional links between changes in the world outside and the physiological responses that enable plants to counter or exploit them. The second term concludes with an overview of microbial physiology, and considers how microbes and plants interact. 

The third term takes a more integrative approach, drawing on what you now know about plant and animal physiology. We consider the profound importance of body size and scaling in both groups of organisms, exploring aspects such as structure and locomotion. 

Experimental practical classes allow you to explore for yourself what you hear about in lectures, and see how science is actually done. In the animal physiology classes you will, among other things, look at the properties of nerves and muscles, examine the activity of your own heart, discover how the body adjusts to exercise and even see how much sweat you produce while pedalling on a bicycle ergometer! In the Plant Sciences practicals you will explore how leaves control gas exchange, how enzyme regulation contributes to plant nutrient acquisition and how plants respond to viral infection. 

The Physiology of Organisms course gives a contemporary and integrated understanding of how organisms function. It provides a wider context for the material in the other 1A biology courses and represents a strong background for many of our IB well as being of general interest to anyone curious to know how complex biological machines work.

Knowledge of A2-level Biology (or equivalent) is not assumed in this course but is certainly very helpful, as is familiarity with mathematics up to at leave AS level. Some knowledge of chemistry and physics at AS or A2 level can also be helpful, but most of our students do not have a physics background. 

Programme Specification: Part IA Physiology of Organisms

This course is taught jointly by the Departments of Plant Sciences, Physiology, Development, & Neuroscience, and Zoology.


  1. to provide a course of basic comparative physiology, introducing students to the principles of normal biological function in a wide range of organisms;
  2. to prepare students for subsequent biological courses that require an understanding of the physiology of organisms;
  3. to compare how animals and plants maintain an internal steady state, how they acquire nutrients and how they detect and respond to changes in their environments;
  4. to outline the physiology of bacteria and fungi;
  5. to consider the influence that body size has on physiology;
  6. to develop practical biological skills.

Learning outcomes

At the end of the course students should:h

  1. ave an enhanced knowledge and appreciation of the physiology of organisms;
  2. be able to explain the similarities and differences in how animals and plants maintain an internal steady state, how they acquire nutrients and how they detect and respond to changes in their environments;
  3. be able to outline the basic physiology of bacteria and fungi and how they interact with other organisms;
  4. understand the influence that body size has on physiology;
  5. be able to develop cogent and critical written arguments, requiring the integration of related topics from separate parts of the course;
  6. be familiar with the safe use and application of some of the basic laboratory equipment used in physiological studies of plants and animals;
  7. be able to perform, critically analyse and report on experiments and observations in physiology;

Teaching and learning methods

These include:

  • lectures, practical classes and practical feedback provided in seminar format or through online notes;
  • additional, web-based resources;
  • College-based supervisions.


Assessment for this course is through:

  • one unseen written examination, covering the theory parts of the course (for aim 6 and learning outcomes 1-5);
  • one unseen written examination, assessing the practical material (for aims 1-5 and learning outcomes 1-4).

Courses of Preparation

Essential: None.

Recommended: A2 Level Biology and AS/A2 level Mathematics.  AS/A2 level Chemistry and/or Physics will also be useful.  Most of our students would not have Physics though.

Additional Information

Further information is available on the Course Websites pages.