1. Specialized cells found in certain cyanobacteria (blue-green algae) that are adapted for nitrogen fixation and are typically larger and more heavily pigmented than vegetative cells.
Usage: biology; plural form of heterocyst; technical term used in microbiology and botany

Examples

• Heterocysts are essential for nitrogen fixation in filamentous cyanobacteria.
• The presence of heterocysts allows certain algae to thrive in nitrogen-poor environments.
• Under nitrogen limitation, cyanobacteria develop heterocysts along their filaments.
• Heterocysts have thick cell walls that protect the nitrogen-fixing enzyme nitrogenase from oxygen.
• Scientists study heterocysts to understand how some organisms can convert atmospheric nitrogen into usable forms.