Question

if you mix bacteria into agar and let it sit undisturbed, and 48 hours later you see growth only at the very top of the agar column, you know that your bacteria were

Answer 1

If you see growth only at the top of the agar column after mixing bacteria and letting it sit undisturbed, it indicates that your bacteria are aerobic. They require oxygen for survival and will tend to grow where oxygen is most available, i.e., at the top.

Step-by-step explanation:

When you mix bacteria into agar and let it sit undisturbed, observing growth only at the very top of the agar column after 48 hours usually indicates that the bacteria you have are aerobic. Aerobic bacteria require oxygen for their survival and multiplication. As oxygen is more available on the surface, these bacteria tend to concentrate and grow at the top. This is quite unlike anaerobic bacteria, which don't need oxygen and can grow evenly dispersed throughout the agar.

Learn more about Aerobic Bacteria