title: Biology of the hen.
mesh_terms: D000822:Animal Husbandry; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001831:Body Temperature; D002645:Chickens / Q000033:anatomy & histology / Q000502:physiology*; D004064:Digestive System / Q000033:anatomy & histology; D004068:Digestive System Physiological Phenomena; D005260:Female; D008027:Light; D010058:Oviposition; D012098:Reproduction; D012143:Respiratory Physiological Phenomena; D012137:Respiratory System / Q000033:anatomy & histology; D012741:Sexual Maturation