Endospores are primarily formed by which group?

• A. Gram-negative bacteria
• B. Archaea
• C. Gram-positive bacteria
• D. Fungi

Answer: (C)

Endospore formation is a survival strategy used by certain Gram-positive bacteria. These organisms, especially Bacillus and Clostridium species, undergo sporulation when nutrients are scarce, producing a durable endospore inside the mother cell that can resist heat, desiccation, and chemicals. Gram-negative bacteria generally do not form endospores, and fungi reproduce by different spores rather than endospores inside a mother cell. Archaea do not form the classic bacterial endospores either. So the group primarily associated with endospore formation is Gram-positive bacteria.