The basic unit of classification of living things is the

Step 1: Analyze the question The question asks for the basic unit (the fundamental, smallest working group) in the classification of living things (taxonomy).

Step 2: Explain the concept Living things are classified in a hierarchy, from the biggest group to the smallest:

Kingdom → Phylum (Division in plants) → Class → Order → Family → Genus → Species

• The kingdom is the largest and most general group.
• The species is the smallest and most specific group in the hierarchy.

A species is a group of organisms that are structurally similar and can interbreed to produce fertile offspring. Because every higher group (genus, family, and so on) is built by grouping related species together, the species is regarded as the basic unit of classification.

Step 3: Go through the options

• A. Class: a high-level group made up of several orders. Not basic.
• B. Genus: a group of closely related species. It is above the species.
• C. Kingdom: the largest group. It is the opposite of basic.
• D. Phylum: a very large group of related classes. Not basic.
• E. Species: the smallest group, made of individuals that can interbreed. This is the basic unit.

Step 4: Answer The correct option is E. species.

Exam tip: Remember the order with the phrase "King Philip Came Over For Good Soup" (Kingdom, Phylum, Class, Order, Family, Genus, Species). The last word, Soup (Species), is the basic unit. Also remember that the scientific name of an organism uses the genus and species, for example Homo sapiens.