What is the function of a spore in bacteria?

A spore serves the vital function of protecting bacteria when environmental conditions become unfavorable, particularly in the absence of nutrients. Under harsh conditions, such as extreme temperatures, desiccation, or lack of food, certain bacteria can form spores, which are resilient and can survive for long periods until conditions improve. This survival strategy allows bacteria to endure until they can return to a more favorable environment where they can germinate, grow, and reproduce.

The other options describe processes or functions that do not accurately reflect the role of spores in bacterial survival. Rapid reproduction in food pertains to the bacteria's normal growth cycle when conditions are ideal. Metabolism refers to the biochemical processes that sustain the bacteria while they are active, not during their dormant spore stage. The creation of toxins does occur in some bacteria but is not related to the formation of spores; rather, it is a separate mechanism used for survival and proliferation under different circumstances.