Biology: is the the branch of science that deals with the living organisms and their vital processes.

Characteristics of Life:

• Nutrition: is the food required for correct mechanism of body.

• Respiration: is the release of energy by the breakdown of food substances like glucose into carbon dioxide and water.

• Excretion: is the removal of metabolic waste products that have been produced as a result of processes occurring inside the cells of organisms.

• Growth: is a permanent increase in the mass and volume of an organism as an result of converting absorbed food into living protoplasm.

• Movement: is the physical characteristic of an organism.

• Sensitivity: is the property of living organisms that result in an appropriate response to a stimulus (change).

• Reproduction: is the process in which new offsprings are produced by the parent.

• Adaptability: is the ability of species to change so as to improve its chances of survival.

How to classify organisms?

• Prokaryotae: the bacteria.

• Protoctista: a collection of single-celled organisms and some simple multicellular ones like seaweeds.

• Fungi: the mushrooms,toadstools, moulds and so on.

• Plantae: the green plants.

• Animalia: the animal kingdom which includes humans.

• Viruses: smallest organisms which can’t be classified as living or nonliving.