Question

Which of the following characteristics correctly describes the Jurassic period of the Mesozoic era?

• A. Conifers were the dominant plants
• B. Origin of mammal-like reptiles
• C. Dinosaurs became extinct
• D. Flowering plants and first dinosaurs appeared

Answer 1

The correct option is A Conifers were the dominant plants

The entire life span of the Earth is called geological time and it is represented in the form of eras and periods which is called the geological time scale.

Plants and animals have changed gradually during the passage of geological time and present a chronological sequence of events which led to the evolution of more diversified forms.

The geological time scale is divided into eras like Paleozoic, Mesozoic and Cenozoic.

Each era is further divided into periods. The Paleozoic era is divided into Silurian, Devonian, Carboniferous and Permian periods.

The end of the Paleozoic era is marked by the Permian period. The reptiles which appeared during the Carboniferous period diversified during the Permian period. The mammal-like reptiles, therapsids, now extinct, dominated the land earlier throughout the Permian period.

The Paleozoic era is followed by the Mesozoic era.

The Mesozoic era is divided into: Triassic, Jurassic and Cretaceous periods.

Dominance of gymnosperms with the origin of angiosperms happened in this Mesozoic era. Conifers were the dominant flora of the Jurassic period. The angiosperms or flowering plants emerged and diversified during the Cretaceous period of the Mesozoic era.

First dinosaurs appeared in the Triassic period of the Mesozoic era (beginning stage). The Jurassic period has witnessed the evolution of giant reptiles like dinosaurs. Dinosaurs were dominant during the Jurassic period. The Cretaceous period, ending the Mesozoic era, witnessed the extinction of dinosaurs.