In this topic you will learn how organisms are classified and named.

A way to classify organisms is by their physical characteristics. Scientists also classify organisms by body form and how they get their food. They also look at the number of cells, the cell parts, and if an organism moves from place to place.

A kingdom is the largest group into which an organism is classified. Organisms in each kingdom share basic traits. A trait is a characteristic of a living thing. Organisms within a kingdom are similar to one another but are different from organisms in other kingdoms.

Scientists use smaller and smaller groups to further classify organisms. The smaller the group, the more similar the organisms in it are to each other. There are seven groups into which an organism can be classified. The kingdom is the largest group. A phylum is a large group within a kingdom. A phylum is broken down into smaller groups, each called a class. A class is made of smaller groups called orders. An order is made of still smaller groups of similar organisms. These groups are called families.

A family is made of organisms belonging to a genus. A genus is made of two or more very similar species. Dogs and wolves belong to the same genus. The smallest group into which an organism is classified is a species. A species is made of only one type of organism that can reproduce only with another organism of the same species. All dogs belong to the same species.

The first part of an organism's name is that organism's genus. The second part of its name is its species. The genus name for a lion is Panthera. Other large cats have the same genus name. Only the lion has the full name Panthera leo.

In places such as the rainforest, some animals still are not classified. Scientists are working hard to find and classify them. Some rainforest plants and animals are important in producing medicine. Classifying organisms helps people keep track of organisms, organize them into groups, and communicate about them using the naming system.