Question

Pasteur succeeded in disproving the spontaneous generation theory because:

• A. The sample of yeast taken by him was dead
• B. The surrounding of his laboratory was clean
• C. The neck of the glass flask was so designed as to allow air to enter, but not the microbes
• D. He was lucky

Answer 1

The correct option is C The neck of the glass flask was so designed as to allow air to enter, but not the microbes

In his experiment, Pasteur used broths in two kinds of glass flasks - a control flask which he kept as it was, and another flask that was curved or swan necked. Both were kept open to the environment. The curve prevented dust particles and their load of microbes from reaching the inside of the swan necked flask. After prolonged incubation the swan necked flask remained free of life, whereas the control flask was teeming with microbial life. Thus, Pasteur succeeded in disproving the spontaneous generation theory because the swan neck of the flask allowed only air, and not the microbes.