What is biology?

A forest. Full of life. Living birds, squirrels, moss, and trees. But what's happening? The trees are cut..

Sawn.. And become.. A building. And in that process the trees went from living organisms -- to an inanimate thing. A building.

What is it that makes one thing alive and something else not alive? What is life? How do various forms of life differ from each other? And what is required for a living creature to function in its environment? The answers to these questions, we seek in Biology.

The scientific study of life, living things, and their interactions. But what is "life"? Well, there are some basic properties that are common for everything living. The most important of these are... ... that everything living consists of cells.

Cells are the building blocks of life. ... that everything living needs energy. Organisms can convert nutrients - food - to energy in complex chemical processes. Plants use sunlight as their energy source. ... that everything living reproduces.

Animals have offspring, and plants spread seeds. Properties are inherited from generation to generation. ... that everything living changes. Over billions of years, life has evolved. New species have occurred, others have become extinct.

This process goes on and on. It takes place in tiny steps over many generations, by the organism's adaptation to its environment. The process is called evolution. -- The study of life-forms and their interaction with their surroundings is as old as mankind. Early humans studied animals and their behaviour, to hunt more successfully. The more they understood, the better chance they had to find food for themselves and their children.

They also collected knowledge about plants. So instead of just gathering plant foods and hunting animals, they learned how to farm them. Biology has its roots in the age of early humans, but not until many centuries later, we can call Biology a science: something that is studied systematically and methodically. In the 18th century, scientist Carl Linnaeus carried out meticulous studies, mainly of plants. Linnaeus was one of those who laid the foundation for Biology as a modern science.

And Biology has continued to develop since then. Today, doctors have advanced knowledge of how the body works, and can treat illnesses that would have been lethal a hundred years ago. Thanks to -- Biology. We have gathered knowledge of how to develop crops, so that agriculture becomes more efficient. This has saved millions of people from starvation, worldwide.

This knowledge is -- Biology. Biology is a field of research important to our everyday lives today, in many ways. Biology is divided into various branches. The study of animals is called Zoology. The study of plants is called Botany... ...

the study of how organisms interact in nature is called Ecology. The list is a lot longer than that. Biology is an extensive subject. And we've just begun to scratch the surface of it. We have a lot more to learn.

About life. Nature. And ourselves.