Holozoic organism means which takes food and then ingest it then digest after that absorb accimilate antd then thrown out of body .the digestion is must in holozoic bz it is harmful for us if it is not digested and the undigested food should be thrown out of body. we digest whe we eat food and food is the basic need of human it provides energy and if food is not digested then our body is nothaving energy which we through a process called respiration