THE CELLWHAT IS CELL? IS CELL A LIVING THING?
Definition of a cell
The cell is defined as the structural and functional unit of a living thing or organism. In other words, the cell is the simplest, smallest and basic unit of life.
All living things including plants and animals are made up of cells. The cell is regarded as the basic of all living thing because they or it can carry out life activity such as feeding, reproduction, respiration, movement and excretion. All these characteristics exhibited by a cell are the reasons the cell is called a living thing.
CHARACTERISTICS OF LIVING ORGANISMS BASED ON THE NUMBER OF CELLSLiving organisms are classified into two major group based on their number cells, they are
a. UNICELLULAR OR ACELLULAR ORGANISMS
These organisms which consists only of one cell. Examples of unicellular organisms are Amoeba, Chlamydomonas, Euglena and paramecium
b. MULTI-CELLULAR ORGANISMS
These are organisms which consists of two or more cells. Which means th4ese group of organisms is made up of multiple cells. Examples are Volvox, Spirogyra, man, flowering plants and birds
HISTORY OF THE CELLMany scientists contributed to history of the cell theory. Amongst thee brave scientists are
ROBERT HOOKSRobert Hooks is an English scientist who should or can be seen as the father of cells. He was the first human to discover the existence of the honey comb structure of the cell in 1665.
In his book, Micrographia, he described his observations of a magnified thin slice of a cork of an oak tree. He established that the cork is made up of a thin component or rooms. He4 then named these components cells.
FELIX DUJARDINThis guy is a French Biologist in 1835 who discovered the cells are made up of living substances called protoplasm.
MATTHIAS SCHLEIDENHe is a German botanist who in 1838, revealed that the bodies of plants are made up of cells which are described as the units of life
THEODOR SCHWANNThis is another German zoologist in 1839 who discovered that the bodies of animals are made up of cells. The discoveries of Schleiden and Theodor led to the postulation of the cell theory in the year 1839