TeXes Science Practice Test

What defines a species in biological terms?

1. A group of populations that can interbreed

2. A solitary group of organisms

3. A classification based solely on morphology

4. A collection of individuals that do not breed

The correct answer is: A group of populations that can interbreed

In biological terms, a species is defined as a group of populations whose members can interbreed and produce fertile offspring under natural conditions. This concept, often referred to as the biological species concept, emphasizes the ability to mate and create viable offspring as the crucial factor. A group that can interbreed shares genetic similarities and a common gene pool, which contributes to the evolutionary continuity of that group. The other options lack this core element of reproductive capability and interaction within a population. A solitary group of organisms does not account for the relational dynamics and reproductive connections that define a species. Classifying based solely on morphology ignores the genetic and reproductive relationships that can distinguish different species with similar physical characteristics. Lastly, a collection of individuals that do not breed does not align with the essence of what constitutes a species, as reproductive isolation contradicts the very definition of being a species in the biological sense.