<P> In biology , a species is the basic unit of biological classification and a taxonomic rank . A species is often defined as the largest group of organisms in which two individuals can produce fertile offspring , typically by sexual reproduction . While this definition is often adequate , when looked at more closely it is problematic . For example , with hybridisation , in a species complex of hundreds of similar microspecies , or in a ring species , the boundaries between closely related species become unclear . Other ways of defining species include similarity of DNA , morphology or ecological niche . </P>
<P> In biology , a species is the basic unit of biological classification and a taxonomic rank . A species is often defined as the largest group of organisms in which two individuals can produce fertile offspring , typically by sexual reproduction . While this definition is often adequate , when looked at more closely it is problematic . For example , with hybridisation , in a species complex of hundreds of similar microspecies , or in a ring species , the boundaries between closely related species become unclear . Other ways of defining species include similarity of DNA , morphology or ecological niche . </P>
what is the term for a group of individuals that can breed and produce fertile offspring
what is the term for a group of individuals that can breed and produce fertile offspring
species
species