Ways by which GMO’s have been useful for enhanced crop output - - Make crops more tolerant to abiotic / cold / heat / drought / salt stresses.- Reduces reliance on chemical pesticides (pest-resistant crops).- Reduce post harvest losses.- Increased efficiency of mineral usage by plant (prevents early exhaustion of soil fertility).- Enhanced nutritional value of food (example vitamin A enriched rice / starch).- To create tailor-made plants for non food purposes (to supply alternative resources of fuels / pharmaceuticals to industries).