Answer
Van Leeuwenhoek's discovery was important because no one else had ever seen single-celled animals before. While Hooke had been able to use microscopy to discover cells, he had not seen living organisms too small to be seen with the naked eye. By establishing the existence of microorganisms such as bacteria, van Leeuwenhoek paved the way for Pasteur's experiments and to the germ theory of disease, which enabled the effective treatment of many diseases.
Work Step by Step
1. Hooke had been able to observe cells, but not single-celled organisms, or microorganisms.
2. Before van Leeuwenhoek, nobody knew that microorganisms such as bacteria existed. His microscopic observations established that they do exist.
3. More than a century after Leeuwenhoek's death, Louis Pasteur was enlisted by French winemakers to uncover what was causing their wines to turn sour.
4. Pasteur was able to show that a bacterial strain was the cause, and devised a heating process to kill the bacteria which became known as pasteurization, and is now also used in milk.
5. Pasteur's research into bacteria also showed how they caused disease, and theorized that people could become immune to some diseases by being injected with weaker strains of the disease-causing bacteria. This has also proved successful.
6. If Pasteur had not known what bacteria was, he could not have devised his germ theory of disease or pasteurization. The fact that he did know was due to van Leeuwenhoek.
