Answer: A group of organisms that can interbreed with one another to produce viable and fertile offspring.
Explanation:
The biological species concept is described by a group of organisms that are able to potentially interbreed with one another to produce viable and fertile offspring. For example, potentially interbreed means that if a population of frogs is divided by a freeway that could prevent the two groups of frogs from interbreeding, that does not mean they are separate species.
Also, this definition is not according to similarity of appearance. Although appearance is helpful in identifying species, it does not define it.
