Question

Select the statement(s) that accurately describe how the evidence for spontaneous generation changed.
Hint! Spontaneous generation is the idea that living organisms come from nonliving things.

Boiled broth did not have any organisms living inside.

Small organisms were caught in the neck of the flask and did not reach the broth.

The broth was boiled and then Pasteur saw living organisms inside.

Over time, living organisms grew in the broth even though the flask was closed.

Pasteur found that organisms in the broth came from outside the flask.

Answer 1

True: Boiled broth did not have any organisms living inside.
- Spallanzani and Pasteur showed that properly boiled broth stayed free of microbes unless contaminated afterward.

True: Small organisms were caught in the neck of the flask and did not reach the broth.
- Pasteur’s swan‑neck flasks trapped dust and microbes in the bend, preventing them from reaching the broth.

False: The broth was boiled and then Pasteur saw living organisms inside.
- Pasteur did not see life appear after boiling unless the flask was later exposed or the neck was broken.

True (historical claim): Over time, living organisms grew in the broth even though the flask was closed.
- This describes earlier experiments (e.g., Needham) that seemed to support spontaneous generation, but those results were later shown to be due to contamination or inadequate heating/sealing.

True: Pasteur found that organisms in the broth came from outside the flask.
- Pasteur’s work showed microbes entered from the air/dust, overturning spontaneous generation.