Definition: This is the newest classification system with the highest rank of domain, followed by kingdom. There are three domains; one eukaryotic domain and two prokaryotic domains.
Example: Domain Eukarya - Protista, Fungi, Plantae, Animalia
Hint: First 2 Letters: si

The newest classification system with the highest rank of domain, followed by kingdom corresponds to the Six Kingdom System.

Explanation:

The system of the six kingdoms was proposed last century, in the 80's, and currently remains in force. The advent of technology for genetic analysis at that time allowed studies in RNA and DNA that led to the differentiation of bacteria and archaea, establishing them in two kingdoms.

According to this classification system, there are two kingdoms of prokaryotic organisms and four eukaryotic kingdoms:

Prokaryotic domain:

Eukaryotic domain:

Much of the scientific world accepts this taxonomic classification system, which is considered more complete than its previous versions.

Lear more:

Six Kingdom System link