In winter reindeer rely on high-carbohydrate lichens called reindeer moss, which they reach by digging craters in the snow. The calf follows its mother and shares this food. The reindeer survive on this low-protein diet by recycling urea (normally a waste product) within the digestive system and making use of its nitrogen.
What do reindeer eat in the winter?
What are the basic functional systems of animals?
Animals’ basic functional systems include a musculoskeletal system, for supporting and moving the body; a nervous system, for receiving and processing sensory information and for carrying signals to control muscle and hormone activity; an endocrine system, for secreting hormones to chemically control bodily functions; a digestive system, for receiving and processing food; a circulatory system, for carrying nutrients and oxygen to cells and carrying away their wastes; and a reproductive system, for producing offspring to ensure species survival.