The dormant body formed by bacteria in the later stage of growth and development is also called _ _ _ _ _ _, which has strong resistance to adverse environment.

The reproductive mode of bacteria is fission reproduction. Spore is a circular, elliptical or cylindrical dormant body formed by some bacteria in the late growth period, and most of them can produce spores. The shell of sporogenous mother cells is called spore sac. Spore has the characteristics of strong heat resistance, radiation resistance, chemical resistance and hydrostatic pressure resistance, which is the highest in the life world. Therefore, some bacteria will form spores when the environmental conditions are not conducive to growth and reproduction. When the spores fall in a suitable environment, they will germinate again to form a new individual. Therefore, spores are not a reproductive mode of bacteria, but a special dormant body. < P > Therefore, the answer is: spores.