Classification is the arrangement of organisms into similar or related groups. We classify living things based on evolutionary relationships and similarities in their biological structures, beginning with the most general. Once an organism is classified, it can be given a scientific name. Taxonomy is the science of identifying, classifying and naming living things. The classification tree in the video looks like there are only a few phyla. In reality, each kingdom branches into many phyla—we just didn’t have room to show all of them! The kingdom of Animalia alone contains over 30 phyla. These include Echinodermata, which means “spiny skin” and contains organisms like sea urchins and starfish; Annelida with long, segmented bodies like earthworms; and Chordata with spinal cords, like humans. Each phylum branches into many classes and each class into many orders, and so on down to species. There are 1,470,000 species in the animal kingdom in total.

Which of the following best describes the relationship between kingdoms and phyla?

A
There is always an equal number of kingdoms as phyla.

B
A single phylum branch out into over 30 kingdoms.

C
Each of the six kingdoms has exactly 30 phyla in it.

D
Many different phyla make up each kingdom.