Question Video: Defining the Term Species Biology • First Year of Secondary School

Video Transcript

Which of the following best describes a species? (A) A species is a group of similar organisms that can reproduce. (B) A species is a group of organisms that had a common ancestor in the last millennium. (C) A species is a large group of organisms that inhabit the same ecological space. (D) A species is a group of organisms that can breed to produce fertile offspring. Or (E) a species is a group of organisms that are genetically identical.

Species is the smallest and most specific rank in a taxonomic system. A species is a group of organisms with similar characteristics. However, organisms in a genus, or any of the other taxonomic groupings, also have similar characteristics. How do we know that organisms are similar enough to be called the same species?

First, they must be similar enough that they can reproduce with each other. But not only that, the offspring need to be fertile. Some organisms that are not in the same species, such as a lion and a tiger, can reproduce, but the offspring are not fertile. Therefore, they are not the same species.

So, the correct answer is (D). A species is a group of organisms that can breed to produce fertile offspring.