Introduction to Biology

Biology is a word derived from two Greek words i.e. Biosand logoswhere Bios means life and logos means knowledge.    

Therefore Biology is a branch of science which deals with the study of life or living things. All living things are called organisms.


  1. Taxonomy, the study of classification of organisms
  2. Bacteriology, the study of bacteria.
  3. Genetics, the study of inheritance of characteristics of organisms
  4. Nutrition, the study of food and how living things feed.
  5. Zoology, the study of animals.
  6. Botany, the study of plants.
  7. Microbiology, the study of microorganisms.

Other branches of biology include

  • Anatomy, the study of the structure of living things.
  • Physiology, the study of how the body works.
  • Ecology, the study of how organisms are related to their environment / surrounding.
  • Mycology, the study of fungi.
  • Virology, the study of virus.
  • Entomology, the study of insects.
  • Physiology, the study of process and functioning of the body parts.


  1. Nutrition/feeding

It’s a process by which living things obtain.

All living things take in food from which they obtain materials for energy production, body growth, and Repair.

Green plants make their own food while the rest obtain already made food from the environment.

  • Respiration

Is the breakdown of food to release energy in the body.

  • Excretion

Process by which waste products are removed from the body e.g. urea in urine, carbondioxide, etc.

  • Reproduction

Is the ability of an organism to give rise to new organisms.

  • Movement

Is the ability of an organism to transfer its body from one place to another. They move in search for food, water, shelter, mates, and run away from predators.

  • Growth

Growth is a permanent increase in size of an organism. It is followed by development.

  • Irritability / sensitivity

It is the ability of an organism to respond to changes in its environment