Biology Kenya
Introduction to Biology
Introduction to Biology
Introduction to Biology
Definition of biology
Biology is a branch of science that deals with the study of living things. All things in the world aregrouped as either living things or non living things.
So biology can be defined as a branch of science which deals with the study of life. The term biology can also be defined as a branch of science which deals with the study of living things or organisms.
Biologist
A person specialized in the study of biology
Life
Life means being alive or existing. Something is alive or existing if it possesses life processes. The life processes are growth, movement or locomotion, respiration, excretion, reproduction, sensitivity and nutrition.
Organism
Organism is anything which has life. It is the other name of a living thing. Organisms are made up of cells.
Cell
A cell is a basic unit of living things. The cell has three main parts, cell membrane, cytoplasm and nucleus. Cells which make up plants are called plant cells and those which make up animals are called animal cells.
Some organisms are made up of one cell. They are called unicellular or single-celled organisms e.g. amoeba, euglena and yeast. Some organisms are made up of many cells, they are called multi cellular organisms e.g. animals, plants, and most fungi.
Branches of biology
Importance of biology
The study of biology is very important to man.The following is an outlines of why the study of biology is important:
- It helps us to understand ourselves better since we are living things.
- Skills and knowledge of biology can be applied to other scientific fields such as agriculture, forestry medicine, nutrition, pharmacy and veterinary science.
- It helps us to understand our environment better and principles of conserving it.
- Biology helps to answer some important questions such as, what do living things need, why do we resemble with a monkey, why do frogs lay many eggs but only few become adults?
- Knowledge of biology helps us to improve our health since causes, symptoms, transmission and treatment are of various diseases are studied in biology.
- Knowledge of biology helps us to avoid our selves from magical beliefs, superstitions and other traditional taboos.
- Knowledge of genetics helps us to clear some common doubts about certain inherited characteristics e.g. albinism, sickle cell anaemia, haemophilia, etc.
- Knowledge of the structure and chemical composition of the organisms enable us to acquire food, clothes and shelter from them.
Characteristics of living organisms
Movement/locomotion
All living organisms are capable of movement. Movement is the change of position of the whole organism or just part of an organism. For animals and unicellular organisms the movement is of the whole body. This is known as locomotion. Most animals move about using legs, wings or fins. Unicellular organisms such as amoeba, paramecium and euglena use the locomotory structures pseudopodia, cilia and flagella respectively.
In plants only part of it may move towards different factors such as light, water, gravity etc. They move by growing. Their roots grow down in the soil and their shoots grow up into the air or towards a source of light.
Comparisons between plants and animals
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