Unit 1 Introduction to Biology
Sub-topic Classifi cation of living things
Unit 2 Introduction to classifi cation
Unit 3 The external structure and importance
of fl owering plants
Figure 1.1 There is a great diversity of living things in Rwanda.
UNIT 1 Introduction to Biology
Key Unit Competence
be able to explain the meaning of biology and its application, recall the
characteristics common to all organisms and be able to apply safety and first aid
in daily life.
At the end of this unit, you should be able to:
• Define Biology and state its main branches
• Explain the importance of studying Biology
• Identify different forms of life from a wide range of organisms
• List the characteristics of living things
• Explain the principles of the first aid and how and when first aid kit is used
• Compare characteristics of life throughout different groups of organisms
focusing on their nutrition, respiration, excretion, reproduction, growth,
sensitivity and movement
• Compare living things and explain their differences
• Practice rules and regulations governing the laboratory and know how to
• Use first aid kit
• Know what to do if someone is injured in the laboratory
• Acknowledge the diversity and uniqueness of different organisms
• Appreciate the importance of Biology in society.
Environment and sustainability: Biology will help us understand how living organisms interact with their environments and how they keep a healthy balance to survive.
In groups, think about what you learnt in previous grades, and then
brainstorm the answers to these questions.
1. Name the two main groups of animals, and give an example of each.
2. Name the main classes of animals.
3. Can you think of some diseases that aff ect cattle?
4. What are the main parts of the circulatory system?
Topi Water lily Hippo
Algae, viewed under a Forest cobra Black-headed gonolek
Figure 1.2 Biology is the study of life. Have you seen any of these living things?
2 Topic 1: Biodiversity and classification
What is Biology?
The word Biology comes from two Greek words: bios, which means life, and
logos, which means knowledge. Biology therefore means the study of life, or
Think about the world around us. Every day you see living things.
Some of these living organisms are plants, such as trees, grasses and flowers.
Others are animals, such as birds, insects and dogs. Where do they get their
energy from? How do they move? What are they made of? When we study
Biology, we can learn more about these different aspects of life.
Branches of Biology
Biology is a subject that covers many different aspects. Some examples of
branches of Biology are shown below.
Why study Biology?
Biology is a science that is growing and developing quickly in the
21st century. Scientists who study Biology are known as biologists.
There are many reasons why we study Biology.
• It improves our understanding of diseases and their causes, prevention
• It helps us to meet the needs of a growing population; for example,
through increased food production.
• We can understand the variety of living organisms on Earth, and why
we need to look after all of them.
• We can appreciate how all life on Earth is connected.
• It helps us make decisions about our own health and form our opinions
on controversial issues, such as organ donation.
• It can provide us with career opportunities.