Final answer:
The active and inactive/spore-forming stages of bacteria represent the endospore and vegetative stages in the life cycle of endospore-forming bacteria, allowing them to survive adverse conditions and later return to a metabolically active state.
Step-by-step explanation:
The active stage and inactive or spore-forming stage of bacteria together are referred to as the life cycle of endospore-forming bacteria.
These stages include the endospore and the vegetative cell.
The process of endosporulation involves several stages, culminating in the formation of an endospore that can survive in harsh environmental conditions.
When conditions become favorable again, the endospore germinates and returns to its active form as a vegetative cell, capable of growth and division.