Question

For the purposes of our lab today, we will consider a substance to be mutagenic if the number of bacterial colonies on that substance's plate is greater than __.

Answer 1

In microbiology, a substance is considered mutagenic if the number of bacterial colonies on its plate is greater than 30-300 colonies. This range allows for statistically reliable numbers and accurate counting of individual colonies.

Step-by-step explanation:

In microbiology, a substance is considered mutagenic if the number of bacterial colonies on its plate is greater than the range of 30-300 colonies. This is because plates with too few colonies are not statistically reliable, while overcrowded plates make it difficult to count individual colonies accurately.

The range of 30-300 colonies also reduces the occurrence of multiple bacterial cells forming a single colony, allowing for a more accurate calculation of the colony-forming units (CFU) and the true number of live bacteria in the population.