A term referring to an optional or secondary aspect, often used in the context of regulations or rules.

Describing a biological characteristic that can occur but is not obligatory, e.g., facultative anaerobes.

वैकल्पिक जाति

English Usage: Some bacteria are facultative, surviving with or without oxygen.

Hindi Usage: कुछ बैक्टीरिया वैकल्पिक होते हैं, ऑक्सीजन के बिना या उसके साथ जीवित रहते हैं।