Which of the following is true about the Paleozoic era?

The statement that the Paleozoic era ended with a mass extinction event is accurate. The Paleozoic era, which spanned from approximately 541 million to 252 million years ago, concluded with the Permian-Triassic extinction event, often referred to as "The Great Dying." This event is significant in Earth's history as it led to the extinction of about 90% of marine species and 70% of terrestrial vertebrate species, marking the most severe biodiversity loss in the planet's history.

Understanding the context of this era is vital. During the Paleozoic, a diverse range of life forms evolved, including fish, amphibians, and the first reptiles, alongside significant developments in plant life, such as the emergence of early fern and tree species. The era did not see the dominance of mammals or flowering plants, as those characteristics emerged later in the Mesozoic era. Thus, the assertion about the mass extinction event accurately reflects the defining end of the Paleozoic era.