This test is only done in combination with the initial screening test. HIV RNA tests: The HIV RNA is different than all human RNA, and tests have been developed to detect HIV RNA in a person's blood. This uses a type of test called a polymerase chain reaction (PCR).
Taxonomy refers to the official classifications of plants or animals according to accepted scientific standards and norms. As a group, sharks belong to the superorder called Selachimorpha. They are in the Chondrichthyes class (along with Chimaeras) under the subclass Elasmobranchii.This subclass is also where rays and skates fall and some sharks are thought to be very closely related to certain ray species (even more so than to other sharks, in fact). Selachimorpha is split into Galea and Squalea.The Galea group comprises:his subclass is also where rays and skates fall and some sharks are thought to be very closely related to certain ray species (even more so than to other sharks, in fact). Selachimorpha is split into Galea and Squalea. The Galea group comprises:
With over 500 species of sharks, there are many different shark sizes and shapes. The largest shark (and also largest fish) is the gentle whale shark (Rhincodon typus), which can reach lengths of 39 feet (12 meters). The smallest is the dwarf lantern shark (Etmopterus perryi) clocking in at only 8 inches long.