The Discovery of Cells

In 1665, British physicist Robert Hook published a book called Micrographa. Using a homemade microscope, Hook carefully observed small structures not visible to the naked eye, such as needlepoints and fleas, and recorded them in a book. Figure 2-1 shows a well-known figure in this book. The sketch shows a cork consisting of several small compartments surrounded by walls. Hook named these cubicles "cell" meaning "small room". However, at that time, Hook simply explained the cell wall as a partition of the dead plant cell, and I was not aware that the contents of these compartments are cornerstones of life.

However, according to various observations after 200 years, two Germans, Matthias Jakob Schleiden and Theodor Schwann, claim that these "cells" are the basic functional units common to all lives . This idea has been widely accepted and is now one of the most important concepts in biology.

The discovery of cells in 1665 brought phenomenal progress in science and brought another surprising discovery: cell replication, in other words cloning. Scientists do not have to spend a long time to understand that the same qualified organisms are created by replicating with cells. After the first successful mammal clone in 1997, Dolly Sheep, the world of science is proud but I am not satisfied. - Discussion remains that human cloning / stem cell research should be considered acceptable. Those who prefer artificial replication insist that the benefits of human clones are much greater than negative ones. People who oppose stem cell research came up with unnatural and cruel arguments. This particular procedure is a technical process involving "replication" of human nuclear DNA, this type of cloning is called reproductive cloning.

Scientists can do so-called molecular cloning by the fundamental biological discovery of the 19th century, discovery of cellular tissue, invention of electron microscope, nuclear structure, chromosome, DNA and gene discovery. This is the technique of cloning the smallest biological objects - DNA molecules, their parts, even even individual genes -. Molecular cloning of DNA (usually modified in some way) is incorporated into a vector (eg, bacterial plasmid or phage genome).