A group of individual organisms with fundamental similarities is called species. It can be distinguished from other closely related species on the basis of distinct morphological differences.In case of higher plants and animals, one genus may have one or more than one species, e.g., Panthera leo (lion) and Panthera tigris (tiger). In this example, Panthera is genus, which includes leo (lion) and tigris (tiger) as species. In case of bacteria, different categories are present on the basis of shape. These are spherical, coccus, rod-shaped, comma and spiral-shaped. Thus, meaning of species in case of higher organisms and bacteria are different