Kaplan Nursing Entrance Practice Exam

What phylum includes humans?

1. Arthropoda

2. Chordata

3. Mollusca

4. Porifera

The correct answer is: Chordata

Humans belong to the phylum Chordata, which is characterized by the presence of a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail at some stage of development. Chordates are a diverse group that includes not only mammals like humans but also birds, reptiles, amphibians, and fish. The presence of these anatomical features distinguishes Chordata from other phyla. In contrast, Arthropoda includes invertebrates such as insects, arachnids, and crustaceans, which exhibit a segmented body and exoskeleton made of chitin but do not possess the characteristics of chordates. Mollusca, which encompasses animals such as snails, clams, and octopuses, is defined by its soft-bodied organisms that often have a hard shell. Porifera, or sponges, is a phylum of simple, multicellular organisms that lack true tissues and organs, thus lacking any of the defining traits found in chordates. Therefore, the classification of humans within the Chordata phylum reflects their specific biological features and evolutionary lineage, distinguishing them clearly from invertebrate phyla like Arthropoda, Mollusca, and Porifera