Answer: Similarities-Human and plant organ systems are similar because both transport nutrients, exchange gases, and remove waste. Humans use the circulatory system, while plants use xylem and phloem. Both exchange gases—humans through lungs, plants through stomata. Humans remove waste through excretion, and plants through transpiration or falling leaves.Differences-They differ because humans can move using muscles and bones, while plants stay in place. Humans have a nervous system for quick responses; plants use hormones. Humans reproduce sexually, while plants can reproduce both sexually and asexually.