Major groups of living things

1. Kingdom
2. Phylum or Division
3. Class
4. Order
5. Family
6. Genus
7. Species

Kingdom has the greatest variety of organisms. At kingdom level, organisms show few features in common. As you move down the rank, each unit has fewer and fewer organisms and the members of each unit have more and more features in common. At the species level, organisms are least varied but share more features. Members of the same species can interbreed and produce viable offspring that can, in turn, reproduce. But organisms from different species do not usually interbreed. They do not interbreed because of differences in genetic makeup, physical features, size, and geographical location. However, there are a few exceptions to this rule. Dogs and wolves can interbreed to produce viable offspring. In the table below, some common organisms have been classified from kingdom to species level. This should guide you in classifying other organisms.

TAXONOMY UNIT	HUMAN BEING	DOG	MAIZE PLANT	EUCALYPTUS TREE
Kingdom	Animalia	Animalia	Plantae	Plantae
Phylum or division	Chordata	Chordata	Spermatophyta	Magnoliophyta
Class	Mammalia	Mammalia	Angiospermae	Magnoliopsida
Order	Primates	Carnivora	Poales	Myrtales
Family	Hominidae	Canidae	Poaceae	Myrtaceae
Genus	Homo	Canis	Zea	Eucalyptus
Species	sapiens	familiaris	mays	regnans
Scientific name	Homo sapiens	Canis familiaris	Zea mays	Eucalyptus regnans

For example, human being and donkey. Kingdom Animalia is subdivided into phyla (phylum in singular). Kingdom Plantae is subdivided into division. The phyla or divisions are further subdivided into class. Each class is subdivided into orders. Every order is subdivided into families. Families are subdivided into genera (genus in singular). A genus is subdivided into species. Kingdom, phylum, divisions, classes, orders, families, genera, and species are ranks of classification and are called units or taxa. The following flow chart shows how Kingdom Plantae and Kingdom Animalia are subdivided.