Question

scenario(s) in which airborne microbial contamination of the sterile beef broth is most likely to occur. select all that apply. ▶ view available hint(s) □ scenario a: break near the mouth of the flask □ scenario b: break before the first curve in the s - shaped neck □ scenario c: break between the first and second curve in the s - shaped neck □ scenario d: break after the second curve in the s - shaped neck microorganisms were not present even after long periods. bend prevented microbes from entering flask.

Explanation:

The S - shaped neck of Pasteur's flask traps airborne microbes. Breaking near the mouth (scenario a) or before the first curve (scenario b) would allow microbes to enter the broth. Breaking between the first and second curve (scenario c) or after the second curve (scenario d) keeps the broth protected as the microbes are still trapped in the lower part of the S - curve. So the scenarios where contamination is likely are a and b.

Answer:

a. scenario a: break near the mouth of the flask, b. scenario b: break before the first curve in the S - shaped neck