Science of Living Things – SS1 Biology Lesson Note (First Term)

Biology is the science that studies living things in nature. Science is the study of nature, both living and non-living things. Biology has two main branches, botany (plants) and zoology (animals). Biologists use the scientific method, a systematic series of steps from observation to theory or law, to investigate questions about life.

Behavioural objectives

By the end of the lesson, students should be able to:

• define science and biology, and state the origin of the word “biology”;
• name the main branches of biology;
• list the steps of the scientific method and explain each one briefly;
• describe the pattern used to report an experiment;
• state areas of human life in which biology is applied.

What is biology?

Science is the study of nature (living and non-living things). Biology is a science that studies living things in nature. The word biology was formed from the Greek words “bio” (meaning life) and “logos” (meaning study of).

What are the branches of biology?

The organisms studied in biology are generally classified into plants and animals. Therefore, biology can be subdivided into two main branches:

• Botany: the study of plants.
• Zoology: the study of animals.

Other branches of biology include microbiology, parasitology, anatomy, physiology and biotechnology.

What is the scientific method?

The scientific method is a systematic approach used to investigate enquiries arising from any observation made in nature. Therefore, it is the tool used to unravel the mysteries of life. The steps are:

1. Observation
2. Classification
3. Inference
4. Measurement and identification
5. Hypothesis
6. Experiment
7. Control or conclusion
8. Theory or law

How do the steps lead to one another?

The starting point of the scientific method is observation, which involves the use of the senses to describe what one has seen or felt about an object. The observation then leads to classification, then to inference (logical reasoning) and later to measurement and identification of the existing problem.

This is followed by a hypothesis, which is a reasonable explanation for an observation made and which can be tested experimentally. A tested hypothesis may be accepted, rejected or modified to form a new hypothesis. A tested hypothesis that is found to be repeatedly true within the limits of available evidence becomes a theory.

A theory is therefore an aggregate of many verified hypotheses. An extensively tested and proven theory becomes a law or principle, which is still subject to change due to continual experimentation or research.

What is a controlled experiment?

To carry out a successful experiment (free from false conclusions), a parallel experiment called a controlled experiment is usually set up. This is done by keeping constant all factors affecting the result of the main experiment and varying the factor being tested.

How is an experiment reported?

Experiments should be reported following a generally accepted pattern laid down by scientists. The pattern includes:

1. Aim: the purpose of the experiment.
2. Apparatus/materials required.
3. Method/procedure followed.
4. Observation made.
5. Conclusion based on the observation made and the final result obtained.

Note: Precautions, that is, the care that should be taken against dangers or hazards, can also feature during experimentation.

What is the relevance of biology?

Biology has found great applications in many areas of human life, some of which include:

• Medicine: production of drugs and vaccines for preventing and curing many diseases (for example penicillin), organ transplants (for example kidney or renal transplant) and in-vitro fertilization for infertile couples.
• Agriculture: production of hybrid crops and animals with desired qualities, and the use of biological ideas to control agricultural pests.
• Bioremediation: the use of naturally occurring bacteria to clean up oil spills and toxic chemicals.
• Biotechnology: the use of genetic engineering to fight genetic diseases.
• Food production: production of single-cell protein (SCP) to reduce protein deficiency problems, and food storage and preservation.

Evaluation

1. Define science and biology.
2. Name the two main branches of biology and say what each studies.
3. List the steps of the scientific method in order.
4. What is a hypothesis, and what can happen to it after testing?
5. State three areas of human life in which biology is applied.

Assignment

1. “Biology is a science that studies life.” Explain.
2. State the various professions practicable with adequate knowledge of biology.
3. How relevant is biology to you as a living organism?
4. What is a scientific method?
5. Describe the pattern followed during experimentation in a scientific study.