Is each kingdom of organisms is divided into several classes?

That's a great question! The answer is yes, but it's not always that simple.

Here's a breakdown:

* Kingdoms are the broadest categories in the biological classification system. They are further divided into Phyla (for animals) or Divisions (for plants and other organisms).

* Phyla/Divisions are then subdivided into Classes. So, you can see a hierarchy: Kingdom -> Phylum/Division -> Class.

* Within each Class, there are Orders, Families, Genera, and finally Species. This system of classification helps organize the incredibly diverse life on Earth.

However, it's important to note:

* The exact number and names of Phyla/Divisions and Classes can vary depending on the classification system used. Scientists are constantly refining their understanding of the relationships between organisms.

* The classification of some groups, like viruses and bacteria, is still under debate.

Here's an example:

* Kingdom: Animalia

* Phylum: Chordata (animals with a backbone)

* Class: Mammalia (animals that have fur, give birth to live young, and produce milk)

In summary, Kingdoms are divided into Phyla/Divisions, and then into Classes. This hierarchical system helps us understand the relationships between different organisms.