Monerans have the maximum nutritional diversity as some of them are - autotrophs - can prepare their own food (eg. Cyanobacteria) - heterotrophs - depend on others for food (eg. Escherichia coli) - saprophytes - feed on dead and decaying matter, - parasitic - live on other host cells for survival and cause, - symbiotic - in mutual relation with other organisms (eg. Anabaena ) - commensalism - it is where one organism is benefited and the other is not affected (eg. Salmonella) - mutualism - where both the organisms are benefited