Final answer:
Louis Pasteur is the scientist most responsible for ending the controversy about spontaneous generation by conducting experiments using a swan-neck flask.
Step-by-step explanation:
The scientist most responsible for ending the controversy about spontaneous generation is Louis Pasteur. Pasteur conducted experiments in the mid-19th century using a swan-neck flask to disprove the theory of spontaneous generation. He found that sterilized nutrient solutions did not develop life unless exposed to air, suggesting that life only comes from life.