What is the name for a dormant bacterial cell that can survive for extended periods?

The term for a dormant bacterial cell that can survive for extended periods is endospore. Endospores are highly resistant structures formed by certain bacteria, allowing them to endure extreme conditions such as heat, desiccation, radiation, and chemical exposure.

When environmental conditions become unfavorable for growth, such as nutrient depletion or extreme temperatures, certain bacteria can undergo a process called sporulation, in which they form these endospores. The endospore contains the bacterial genetic material and is encased in a tough, protective coat, enabling it to remain viable for long periods, sometimes even centuries.

This capability is essential for the survival of these bacteria, allowing them to remain dormant until more favorable conditions arise, at which point they can germinate and return to an active, vegetative state. Other answers refer to different structures: plasmids are circular DNA molecules that provide genetic advantages, capsules are protective outer layers that help bacteria evade immune responses, and chloroplasts are organelles found in plant cells, involved in photosynthesis, and are not applicable to bacteria.