IGCSE resources

The unit considers the special features that make living things different from non-living objects. The structure and functions of animal and plant cells is studied. Some particular examples of specialised cells are then considered, which introduces the idea of structural adaptations for particular functions. Movement of substances within, and into living organisms by diffusion and osmosis is studied. The basic nature and properties of enzymes, including the effects of temperature and pH on their action, concludes this unit.

This unit starts by considering the molecules from which living organisms are made, and then looks at food sources for animals and their necessity to build up the structure of their bodies, and also to supply energy. The way in which small molecules can be used to make larger ones is briefly considered, and the idea of a balanced diet is studied.

The requirement for large molecules to be broken down before they can be absorbed through the wall of the alimentary canal is explained in the last section on Animal Nutrition. The functions of the main digestive enzymes are considered, linking back to the work on enzymes in Unit 1. The use of food to supply energy will be covered in more detail in Unit 4.

Plant nutrition is studied by looking at the way in which plants manufacture organic substances using sunlight and inorganic molecules as their raw materials.

Knowledge of cell structure, covered in Unit 1, is extended to look more fully at the structure and function of cells and tissues in a leaf. The idea of adaptation of structure to function should be reinforced when studying the leaf structure.


The movement of water in xylem is studied. Starting with the uptake of water from the soil, the pathway of water movement is followed until water vapour is lost by the leaves. The factors affecting the rate of transpiration are then considered. 

The unit covers the important topic of respiration, which will be met again when the carbon cycle is dealt with in Unit 10. The need for a constant supply of energy for life processes requires a constant supply of oxygen and glucose to respiring cells, and removal of carbon dioxide from them. Gas exchange in humans follows naturally in this unit.


There is considerable opportunity for practical work about respiration. For gas exchange the scope for practical work is more limited, and is mainly examination of the relevant organs.

In this unit the circulatory system is described, including details of the heart and blood vessels. There are limited opportunities for practical work apart from studying the relevant organs. The effects of exercise on heart rate are then studied. This gives an opportunity for practical work. The composition and functions of blood, including defence against disease are then covered.

The theme running throughout this unit is communication within the body, through chemicals and the nervous system.

The similarity and differences of the mechanisms by which both plants and animals achieve responses to stimuli.

Homeostasis illustrated by temperature regulation in humans and the control of blood glucose concentration

An overview of how negative feedback is involved in control mechanisms

In this unit, general features of both asexual and sexual reproduction are considered, before looking in detail at sexual reproduction in plants. Many learners have preconceived ideas about plants and the more interactive activities usually stimulate the class. The unit should therefore be covered at a time of year when suitable flowers are likely to be available. This is then followed by the biological aspects of human reproduction.

This unit considers the biological aspects of human reproduction.
It is a relatively short unit, with no real opportunities for practical work!
This unit can easily be combined with Unit 9 Inheritance and evolution.

This unit brings together ideas from several earlier units  It also consolidates knowledge of photosynthesis and the topics on respiration and excretion. 


It is hoped that learners will be able to visit a local habitat, even if only in the school grounds, during this unit. The flow of energy from the sun, through producers and consumers is studied, and the causes of energy loss are discussed. The cycling of the element carbon in the environment is also covered in this unit.


Lesson details for G10 Triple Science Biology

This is a short course with the following aims:

  • To help you get ready for further studies
  • To learn some real biological techniques
  • To revisit some IGCSE Biology
  • To develop critical thinking skills
  • To ask questions and seek understanding
  • To discuss ideas and help each other.
  • To improve data analysis skills
  • To enjoy a bit of a challenge