AIIMS 2017 Botany Nitrogen Fixation MCQ Question

Heterocysts in Nostoc are specialized cells that provide an anaerobic environment for nitrogen-fixing bacteria, allowing the conversion of atmospheric nitrogen (N₂) into ammonia (NH₃), which can be utilized by the organism for growth. This adaptation is crucial for survival in nitrogen-poor environments. Option A, fragmentation, refers to a method of asexual reproduction, which is not the function of heterocysts. Option C, symbiotic relation, pertains to interactions with other organisms, while option D, food storage, relates to the accumulation of nutrients, neither of which are the primary roles of heterocysts in Nostoc.