Case study refers to studying about a particular existing organism or a species in detail. The " case " as such may refer to any biological organism right from an amoeba till a human being. In school level case studies are made especially in botany and zoology. In botany case studies are made for every class of plant species, for example, gymnosperms or it may be a specific plant ( like cycas, nephrolepis ). In zoology we do case studies for birds ( Columba livia) amphibians , mammals ( rats)! In colleges ( I refer to medical colleges ) case study refers to humans ( that is patients ) wherein we will have to study the whole history of the patient, his age , sex, habits , clinical manifestations !