Which theory posits that life did not originate on Earth but arrived via extraterrestrial spores or viruses?

• A. Panspermia
• B. Abiogenesis
• C. Endosymbiotic theory
• D. Primordial Soup Theory

Answer: (A)

Panspermia posits that life reached Earth from space, carried by extraterrestrial spores or microorganisms that could survive the journey and seed life on our planet. This idea centers on an external origin rather than life starting here. It’s distinct from abiogenesis, which suggests life began on Earth from nonliving chemicals under early planetary conditions. It’s also different from the endosymbiotic theory, which explains how certain organelles (like mitochondria and chloroplasts) formed within cells through symbiosis, not how life itself began. The primordial soup idea is another Earth-based view of origin, proposing that a mixture of organic molecules in early oceans gave rise to life. Among these options, panspermia uniquely attributes the initial appearance of life to an extraterrestrial source.