When bacteria are inoculated into a new sterile nutrient broth, their numbers don't begin to increase immediately. instead, there is a lag phase that may last for an hour or even several days. why don't bacterial numbers increase immediately?

The correct reason is that the bacteria must amend themselves to the content of the nutrient in the novel medium, has to produce essential amino acids, growth factors, and other enzymes in order to survive.

In the field of microbiology, to inoculate means basically to present or insert one substance into another. For example, one could inoculate a culture of bacteria with some kind of chemical constituent, or it can be said that one introduces the chemical compound into the culture of the bacteria.

Explanation:

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.