Archaea and Bacteria support ecosystems. Bacteria participate in nutrient cycling, organic matter breakdown, and symbiotic connections with plants and animals. They help recycle key components and balance ecosystems. Extremophile archaea help us comprehend Earth's boundaries. Their specific characteristics help them survive and participate in biogeochemical cycles in harsh conditions. Archaea and Bacteria may also create symbiotic connections with other creatures, including humans, altering their health.