The cell theory is one of the fundamental theories in biology that explains the structure and function of living organisms. It states that all living things are made up of cells, which are the basic units of life.

The cell theory has evolved over time with the contributions of various scientists. In this article, we will explore what advanced the cell theory and how it has changed over time.

Early Discoveries

The first person to use a microscope to observe living organisms was Antonie van Leeuwenhoek in 1674. He observed single-celled organisms, which he called “animalcules.”

However, it was not until Robert Hooke’s discovery of cells in 1665 that people began to understand the importance of these microscopic organisms. Hooke used a compound microscope to examine slices of cork and discovered tiny compartments that he called “cells” because they looked like small rooms.

Schleiden and Schwann

In the early 19th century, Matthias Schleiden and Theodor Schwann proposed that all plants and animals are composed of cells. Schleiden was a botanist who studied plant tissues under a microscope, while Schwann was an animal biologist who studied nerve cells. They both independently came to the conclusion that cells were the basic unit of life.

Rudolf Virchow

In 1855, Rudolf Virchow proposed that all cells arise from pre-existing cells through cell division. This idea is known as biogenesis, which contradicted the prevailing idea at the time that living things could arise spontaneously from non-living matter (abiogenesis).

Modern Cell Theory

The modern cell theory includes three main principles:

The modern cell theory is a culmination of the contributions made by many scientists over several centuries. It has been refined and improved as our understanding of cells has grown.


In conclusion, the cell theory has advanced over time through the contributions of various scientists. From Leeuwenhoek’s observation of animalcules to Schleiden and Schwann’s proposal that all living things are composed of cells, to Virchow’s idea that all cells arise from pre-existing cells through cell division, the understanding of the structure and function of living organisms has come a long way. Today, the modern cell theory is widely accepted and serves as a foundation for much of our knowledge in biology.