BASIC CONCEPTS AND TERMINOLOGIES IN BIOLOGY
The term Biology comes from two Greek words, “Bios” that means Life and “Logos” that means study. Therefore;· Biology is the branch of science that deals with the study of life. A person who studies biology is called a Biologist.
· Biology is also defined as the study of life and living things. The living things are also called organisms. They include plants, animals, fungi and micro-organism.
· Microorganisms are very small living things such as bacteria and some protozoans which cannot be seen with the naked eyes.
What is Life?
Life is the quality or state that distinguishes living things from dead or non-living things.
The following are the characteristics of living:
(i) Movement. It is the change of position of the whole organism or part of the organism. All living things can move.
(ii) Reproduction. This is the process by which living things produce new organisms of their own kind. All living things make more of their own kind.
(iii) Sensitivity or Irritability. All living things are sensitive to their surroundings. They are aware of what is happening around them. This is because they have special sense organs such as eyes, skin, tongue, nose and ears.
(iv) Growth. This is the increase in size and weight of organism. All living things get bigger and repair damage.
(v) Respiration. This is the breaking down of food to release energy. All living things take in oxygen and release carbon dioxide
(vi) Excretion. This the process of removing waste products from the body. All living things remove toxic substances from their body.
(vii) Nutrition. This is the process of obtaining food, digesting it and using it to release energy. All living things feed by taking in nutrients in order to obtain energy.
Table 1: The differences between living things and non-living things.
The following are the characteristics of living:
(i) Movement. It is the change of position of the whole organism or part of the organism. All living things can move.
(ii) Reproduction. This is the process by which living things produce new organisms of their own kind. All living things make more of their own kind.
(iii) Sensitivity or Irritability. All living things are sensitive to their surroundings. They are aware of what is happening around them. This is because they have special sense organs such as eyes, skin, tongue, nose and ears.
(iv) Growth. This is the increase in size and weight of organism. All living things get bigger and repair damage.
(v) Respiration. This is the breaking down of food to release energy. All living things take in oxygen and release carbon dioxide
(vi) Excretion. This the process of removing waste products from the body. All living things remove toxic substances from their body.
(vii) Nutrition. This is the process of obtaining food, digesting it and using it to release energy. All living things feed by taking in nutrients in order to obtain energy.
Table 1: The differences between living things and non-living things.
Living things | Non-living things |
| They can respire | They do not respire |
| They can grow | They do not grow |
| They can respond to their surroundings | They do not respond to their surroundings |
| They can reproduce | They do not reproduce |
| They can excrete | They do not excrete |
| They can feed | They do not feed |
| They can move | They do not move |
What is the basic unit of life?
§ A Cell is a basic unit of life. All things are made up of cells.
§ Cells are very small such that they cannot be seen with naked eyes. They can only be seen using the microscope.
§ The microscope is an instrument used to enlarge very small things so that they can be easily seen and examined. The process of enlarging very small things is called magnification.
§ A Cell is a basic unit of life. All things are made up of cells.
§ Cells are very small such that they cannot be seen with naked eyes. They can only be seen using the microscope.
§ The microscope is an instrument used to enlarge very small things so that they can be easily seen and examined. The process of enlarging very small things is called magnification.
THE BRANCHES OF BIOLOGY
The main branches of biology include Zoology, Botany and Microbiology.MAIN BRANCHES OF BIOLOGY | ||
Zoology § The study of animals. | Botany § The study of plants. | Microbiology § The study of microbes (microorganisms). |
| § A person who deals with the study of animals is called zoologist. | § A person who deals with the study of plants is called botanist. | § A person who deals with the study of microbes is called microbiologist. |
Other Branches of Biology That Deal with Different Aspects of Living Things
| Branch | Area of study |
| (i) Anatomy | Body structures and functions. |
| (ii) Cytology | Structure, composition and function of cells. |
| (iii) Ecology | Relationship between organisms and their environment. |
| (iv) Entomology | Insects. |
| (v) Genetics | Heredity and variation in organisms. |
| (vi) Immunology | Immune system |
| (vii) Mycology | Fungi |
| (viii) Parasitology | Parasites and their effects on living organisms. |
| (ix) Taxonomy | Classification system (classification of organisms). |
| (x) Physiology | Physical and chemical processes taking place within living organisms (Body function). |
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