Symbioza

Symbioza is a long-term, close association between different biological species. In symbiotic relationships, at least one partner benefits, and the interaction lasts across life cycles or generations. The category includes mutualism, where both partners gain; commensalism, in which one benefits while the other is unaffected; and parasitism, where one benefits at the expense of the other. Relationships can be facultative (optional) or obligate (essential for survival).

Mutualistic relationships are common and diverse. Lichens result from a symbiosis between a fungal partner and photosynthetic algae or cyanobacteria. Mycorrhizal associations involve fungi and plant roots, enhancing water and nutrient uptake. The gut microbiota of many animals, including humans, aids digestion and immune function. In many coral reef systems, corals harbor photosynthetic algae, supplying energy to the coral host.

Symbiotic interactions are driven by nutrient exchange, protection, and signaling. Some symbioses involve intracellular living, and in evolution, endosymbiotic events have given rise to organelles such as mitochondria and plastids (symbiogenesis).

Symbioses have major ecological importance, influencing nutrient cycling, plant productivity, and ecosystem structure. They have practical applications in agriculture (nitrogen-fixing legumes and their rhizobia, mycorrhizal inoculants), medicine (human microbiomes), and biotechnology. Disruption of symbioses can affect health and ecosystem resilience.