Variety among humans and human characteristics
Organisms in a group have many characteristics in common. This is what helps us to recognise a cat as a cat or a tree as a tree. People are similar to each other in many ways: for example, they have skin, eyes and hair. They have organs inside their bodies, such as heart, lungs and stomach.
Individuals in any group of organisms will differ in some characteristics; this is an example of variation. People are different in many ways, and it is oftenthese differences that children first notice. Differences help us to identify individuals. Differences that are easily recognised include eye and hair colour, height and shoe size.
We inherit certain characteristics from our parents, for example height and eye colour. Some characteristics, such asheight or quality of teeth, can be influenced by factors such as diet. A healthy, nutritious diet may make children grow taller than their parents. Strong teeth may be inherited from parents, but a diet that is full of sugars may cause tooth decay.
In the early years children will be introduced to the external parts of the body. Later on they will learn about the major organs and organ systems, both external and internal. It is important that children realise that there is great variation among all organisms. Not only will this make them aware of their own uniqueness but it may also encourage more tolerance of other people. It may also help them to cope with the rapid changes and growth that will take place as they come towards the end of primary school.
EXEMPLAR 35 - Human variety and characteristics (infant classes)
EXEMPLAR 36 - The body's internal organs (middle classes)
Human life processes
The following life processes can be observed in humans: growth, feeding and digestion, respiration and breathing, movement, sensitivity, excretion and reproduction. Children will be introduced to simple aspects of these processes. They will also learn about factors that contribute to good health, including diet, life-style, personal hygiene, dental care, rest and exercise.
Growth is a gradual process, in which there is an increase in the size of the organism. Children could produce evidence of their growth and development through making collections of photographs, clothes and shoes. Children should appreciate that they grow at very different rates.
Digestion is the process of breaking down food into particles small enough to be absorbed by the gut wall. The blood carries the broken-down food to the cells of the body, thus acting as a transport system. Models of the inside of the body and cut-out pictures can help them clarify their ideas about digestion and the circulatory system. Heartbeat and pulse rates can be compared before and after exercise.
A similar approach can be used to develop ideas about respiration and breathing. Respiration is the process by which food combines with oxygen to produce energy. Oxygen is provided when we draw air into our lungs by breathing in, and waste, in the form of carbon dioxide, is removed when we breathe out. Children can discuss their ideas of breathing and the position and size of the lungs and other parts of the respiratory system. In the senior classes children can suggest ways to measure the amount of air they breathe in and to record and predict breathing rates before and after exercise.
Humans are supported by an internal skeleton of more than 200 bones. Movement of these bones and joints is brought about by muscles. Activities in physical education lessons such as running and jumping may make children aware of movements of bones and muscles. Movements of different bones and joints could be examined in detail and children could make models of limbs from cardboard and rubber bands.
Humans have sense organs such as skin, ears, eyes, nose and tongue with which they can respond to changes in the environment. Children can discover how one sense depends on another by devising games in which they are prevented from using one of their senses, for example trying to identify objects by touch alone without being able to see the object.
In the senior classes children will become familiar with life cycles and this concept can be linked with human reproduction. Questions about where living things come from and where babies grow before they are born may help children to clarify their ideas. Children may not be familiar with terms such as sperm, womb and so on, and it would be important to establish a suitable vocabulary.
EXEMPLAR 37 - Human life processes (infant and junior classes)
EXEMPLAR 38 - Human life processes (middle and senior classes)