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.
Species hypothesized to have the same ancestors are placed in one genus, based on similarities. The similarity of species is judged based on comparison of physical attributes, and where available, their DNA sequences.All species are given a two-part name, a binomial name, or just binomial.ractically, biologists define species as populations of organisms that have a high level of genetic similarity. This may reflect an adaptation to the same niche, and the transfer of genetic material from one individual to others, through a variety of possible means.