Question

John Needham performed an experiment testing spontaneous generation. He boiled chicken broth, placed it in a sterile flask, and then sealed the flask. After a few days, Needham observed microorganisms in the flask. Based on current understanding, how was his experiment flawed?
A. Boiling activated dormant microorganisms present in the broth.
B. Boiling the broth did not kill all microorganisms present.
C. Microorganisms entered the broth from the flask itself after the flask was sealed.
D. After Needham boiled the broth, microorganisms entered from the air.

Answer 1

Answer:

D

Explanation:

John Needham may not have aseptically transferred the broth after it was boiled which might have allow air to enter after the broth was boiled. The experiment has been repeated with control that were not boil; the broth was sealed in the flask and properly boiled; no grow was noticed in the broth plus flask that was boiled properly  and sealed while the control which was not sealed ( exposed to air) had growth suggesting that the microorganism or their spore in the air was responsible for the growth.