A Level Biology Practice Exam

What is the smallest taxonomic group that can interbreed to produce fertile offspring?

1. Genus

2. Family

3. Species

4. Order

The correct answer is: Species

The correct answer is species because it represents the smallest taxonomic group in which individuals share common characteristics and can interbreed to produce fertile offspring. In biological classification, a species is a group of organisms that can mate with one another and have fertile offspring under natural conditions. This concept is fundamental in understanding biodiversity and evolution, as species are often the primary units of ecological and evolutionary studies. The definitions of other taxonomic ranks like genus, family, and order encompass broader groups that may include multiple species. For instance, a genus may consist of several species that share certain traits, but they may not be capable of interbreeding successfully. Similarly, a family includes multiple genera, which makes it even larger and more diverse. An order encompasses several families, further expanding the diversity of organisms that may not necessarily be capable of interbreeding. Therefore, while all these groups form important levels of biological classification, it is the species that is specifically defined by the ability to reproduce and create fertile progeny within its members.