Contributions Questions and Answers
Antony van Leeuwenhoek - answerFirst to observe and describe microorganisms
accurately; greatly improved upon then modern microscopes; considered father of
microscopy, because he discovered the true microscope.
Francesco Redi (SG) - answer(1668) Disproved spontaneous generation for large
animals. Showed maggots came from fly eggs by designing experiment in which raw
meat was placed into a sealed jar and an unsealed jar.
John Needham (SG) - answer(1745)Broth experiment. Mutton in flasks was boiled and
then covered. Broth became cloudy and contained microorganisms. Argued for
spontaneous generation. (Didn't boil flask long enough.)
Lazzaro Spallanzani (SG) - answer(1765) Again boiled broth in two flasks and then
capped one. Growth in uncapped flask, not in capped.
Louis Pasteur (SG theory) - answer(1861) Confirmed Tyndall's findings. Placed nutrient
solution in flasks. Created flasks with long, curved necks. Boiled solutions. Left flasks
exposed. No micro growth. Disproved spontaneous generation.
John Tyndall (SG) - answer(1877) Final blow to SG theory. Demonstrated that dust
carries microorganisms. If dust is absent, nutrient broth remains sterile, even if directly
exposed to air. Also provided evidence for existence of exceptionally heat resistant
forms of bacteria.
Joseph Lister (disease) - answerAntiseptic surgery. Provided indirect evidence that
microorganisms were the causal agents of disease; developed a system of surgery
designed to prevent microorganisms from entering wounds; had patients with fewer
post-op infections.
Louis Pasteur (disease) - answerGerm Theory of Disease. Showed that pébrine disease
of silkworms was caused by a protozoan. Showed that fungi cause diseases of
silkworms.
Robert Koch (disease) - answerEstablished relationship between Bacillus antracis and
anthrax. Used criteria developed by teacher Jacob Henle. These criteria are now known
as Koch's postulates, which are still used today to establish link between diseases and
microorganisms.
Koch's Postulates - answer1. The microorganism must be present in every case of the
disease, but absent from healthy animals. 2. The suspected microorganism must be