The skin is the largest organ of the human body and of all mammals. In the average adult it weighs around six pounds, which is nearly twice the weight of the human brain or liâ¦ver. Internally, the largest organ is the liver which weighs around 1.6 pounds. A curmudgeon with years of practice.
n. pl. species. 1. Biology A group of closely related organisms that are very similar to each other and are usually capable of interbreeding and producing fertile offspring. The species is the fundamental category of taxonomic classification, ranking below a genus or subgenus.. pl. species. 1. Biology A group of closely related organisms that are very similar to each other and are usually capable of interbreeding and producing fertile offspring. The species is the fundamental category of taxonomic classification, ranking below a genus or subgenus.
In biology, a species (abbreviated sp. , with the plural form species abbreviated spp. ) is one of the basic units of biological classification and a taxonomic rank. usable definition of the word species and reliable methods of identifying particular species are essential for stating and testing biological theories and for measuring biodiversity, though other taxonomic levels such as families may be considered in broad-scale studies.