Final answer:
The active phase of bacteria is alternatively known as the log phase or exponential growth phase, where bacteria rapidly divide, show uniform metabolic activity, and are susceptible to antibiotics.
Step-by-step explanation:
The active phase of bacteria is also known as the log phase or exponential growth phase. In this phase, bacterial cells are actively dividing by binary fission, and their numbers increase exponentially. The log phase is characterized by a constant growth rate and uniform metabolic activity.
Cells in the log phase have a genetically determined generation time specific to each bacterial species and growth conditions such as nutrients, temperature, pH, and so on. This intrinsic growth rate leads to exponential growth, which is often plotted on a semilogarithmic graph to linearize the curve for easier interpretation.
Due to the high activity and susceptibility to antibiotics in the log phase, these cells are preferentially used for industrial applications and research work. Antibiotics that affect protein, DNA, and cell-wall synthesis are most effective against bacteria in the log phase because they disrupt crucial processes necessary for bacterial cell growth and reproduction.