Biology
Summary: Biology is the study of living things. In this unit, you will learn about you as a human being, the plants and animals around you, and the many tiny organisms that you cannot see. Tags: science oxford-science student-book-7 biology Created: 2026-05-19 Last Updated: 2026-05-19
Biology
Biology is the study of living things. In this unit, you will learn about you as a human being, the plants and animals around you, and the many tiny organisms that you cannot see.
You will find out what plants and animals are made of, and discover how these different structures work together to keep them alive.
Every second of every day, biology plays a huge part in your life. It determines what you look like, how you complete activities, and why you like (or do not like) certain things. Biology explains why you get ill and how you get better again.
Did you know that the human body has around 30 000 000 000 000 (30 trillion) Cells? Cells are tiny units. They work together to perform the basic functions necessary for an organism to stay alive. However, you do not just have human cells inside your body. You also have millions of bacteria. Some scientists believe that there are more bacterial cells in your body than there are human cells!
The sciatic nerve is the largest and longest nerve in the body. It starts at the bottom of your spine and goes all the way down the back of your leg to your toes. The nerves connected to the sciatic nerve control the movement of your legs and lower body.
Why can some animals only breathe underwater, while others can fly? Biology explains why all of the weird and wonderful organisms in the world, from blue whales to amoebas, exist.
By studying biology, you will find out about the processes happening all around you that allow life on planet Earth.
Biology and the world
We need a good understanding of biology to keep us healthy and to protect animal and plant habitats. Looking after the environment is essential for keeping us and other species alive. We depend on these species in our modern world.
Big Question What are living things made of? Scientists can look at the tiny structures that all living organisms are made of through a microscope.
Big Question How are new plants made? Scientists observe carefully how bees pollinate flowers – the first step in making a new plant.
Big Question How do plants make food? Plants and algae are the only living organisms that are able to transfer Energy from the Sun to make sugars. All other living things rely on plants as a source of food. Scientists continue to work on methods to enable plants to carry out this process more efficiently to give a better result over less time.
