UNLV BIOL 251 EXAM 1 REGNER

Disproved Spontaneous Generation - answer-living organism could arise directly and rapidly from nonliving material. No experimentation. Everything on planet had vital force Francesco Redi (1668) - answer-Fresh air required for life; Flask & Meat study Lazzaro Spallanzini (1776) - answer-Boiled beef broth experiment. Critics claimed heat destroyed vital forces, life requires fresh air. Louis Pasteur (1862) - answer-Disproved spontaneous generation. S curve flask, shown that microorganisms must hit to contaminate not the fresh air. ALL CELLS COME FROM A PREEXISTING CELL Ferdinand Cohn (1876) - answer-discovered bacterial spores, survival structure, resistant to heat & disinfectants, bacillus can be vegetative or endospore state John Tyndall (1876) - answer-Tydallization, boiling for 15 min (3 Con Days), to eliminate contamination, cell theory (cells are fundamental part of life) Germ Theory of Diseases - answer-19th Century (bad luck, bad blood, witchcraft, etc.) Antoni van Leeuwenhoek (1674) - answer-discovered microorganisms, ammalcules from film on teeth, made his own microscope. Biologist found germs everywhere. No experimentation, just speculation Ignaz Semmelweis - answer-Physician in Vienna, babies born by dr (high mortality rate), babies by midwife (low mortality rate). germs from autopsy cadaver infected pregnant women thus came along antiseptic solution John Snow (1854) - answer-London Cholera epidemic (diarrhea diseases), water pump was source of contagion, Vibrio cholera (sewage dumped in Thames river)