6 definitions
The Division of labor (n.) in a floating colony is largely a story: the members that look like defenders and shelter-builders were named for jobs nobody checked.
Immortality (n.) of the individual is a mental construction: metabolism never repeats itself, because neither the materials nor the conditions ever do.
Reproduction (n.) is always regeneration: all the tentacles of a hydra are equally hereditary substance, and no part is only body.
Sex (n.) in the simplest creatures depends on what they eat: change their food and they pair up.
Sexuality (n.) is not a necessity of life but a complication with no clear advantage.
Sexuality (n.) is only a special case of splitting, in which a piece must first unite with a piece from elsewhere before it multiplies.