Evolution Test - 37

The period of Earth's history that began 2.5 billion years ago and ended 542.0 million years ago is known as the Proterozoic. Many of the most exciting events in the history of the Earth and of life occurred during the Proterozoic stable continents first appeared and  a long process taking about a billion years. Also coming from this time are the first abundant fossils of living organisms, mostly bacteria and archaea, but by about 1.8 billion years ago eukaryotic cells appear as fossils too. It is not the age of man. The Mesozoic Era is an interval of geological time from about 252 to 66 million years ago till around 66 million years ago. It is also called the age of reptiles, a phrase introduced by the 19th century paleontologist Gideon Mantell. The Holocene is a geological epoch which began at the end of the Pleistocene and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words meaning "entirely recent". Thus, option B is correct.

• The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 400 mya. It is named after Devon, England, where rocks from this period were first studied. 
• The Devonian period experienced the first significant adaptive radiation of terrestrial life. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. 
• By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. 
• Various terrestrial arthropods also became well-established. Fish reached substantial diversity during this time, leading the devonian to often be dubbed the "Age of Fishes". 
• Ordovician period is the age of invertebrates.
• Mesozoic era is the era of medieval life.
• Cenozoic era is the era where diversification of placental mammal, modern birds, and angiosperms takes place.

Therefore, the correct answer is option A.

The Mesozoic Era is literally the era of middle life. It is also known as the age of dinosaurs. It lasted from 245 to 65 million years ago and is divided into the three periods. The Mesozoic began with the supercontinent Pangaea. Then, during the era, Pangaea broke up and the continents drifted apart. The movement of continents changed climates. It also caused tremendous volcanic activity. Mass extinctions occurred at the end of the Triassic and Cretaceous Periods. The first extinction paved the way for a dinosaur takeover. In the second extinction, the dinosaurs finally disappeared. 

Azoic Age, Azoic Era, Azoic Period and Azoic Eon were terms used before 1950 to describe the age of rocks formed before the appearance of life in the geologic sequence. The word "Azoic" is derived from the Greek, a- meaning without and zoon meaning animal (or living being), it was first used to mean without life. During this era, the earth was with out plants and animals. The rock layers which were formed soon after azoic era contains the remains of limy sea plants. 
Therefore, the correct answer is option D.

The Jurassic Period was the second segment of the Mesozoic Era. It occurred from 199.6 to 145.5 million years ago, following the Triassic Period and preceding the Cretaceous Period. Dinosaurs may have been the dominant land animals, but they were not alone. Early mammals were mostly very small herbivores or insectivores and were not in competition with the larger reptiles. Adelobasileus, a shrew-like animal, had the differentiated ear and jaw bones of a mammal and dates from the late Triassic. Early mammals were developing and diversifying in the Jurassic. Also, Archaeopteryx, the first, primitive, dinosaur-like bird appeared about 150 million years ago, toward the end of the Jurassic. The Jurassic saw the rise of dinosaurs and first birds. Thus, option D is correct.

In 1856, Johann Karl Fuhlrott first recognized the fossil called as "Neanderthal man", discovered in Neanderthal, a valley near Mettmann in what is now North Rhine Westphalia, Germany. The Neanderthals are an extinct species of human in the genus Homo. They are closely related to modern humans differing in DNA by just 0.12%. 

According to the Hardy Weinberg law, the allele frequencies, irrespective of their dominance of recessiveness, in a population remain constant under absence of factors responsible for evolution (natural selection, migration, genetic drift). It states that the sum of all genotype frequencies can be represented as the binomial expansion of the square of the sum of p and q. This sum is equal to one.  

The Cenozoic Era is the most recent of the three major subdivisions of animal history. The other two are the Mesozoic and Paleozoic Eras. The Cenozoic spans only about 65 million years, from the end of the Cretaceous Period and the extinction of non-avian dinosaurs to the present. The Cenozoic is sometimes called as the Age of Mammals, because the largest land animals have been mammals during that time. This is a misnomer for several reasons. First, the history of mammals began long before the Cenozoic began. Second, the diversity of life during the Cenozoic is far wider than mammals. The Cenozoic could have been called the "Age of Flowering Plants" or the "Age of Insects" or the "Age of Teleost Fish" or the "Age of Birds" or "Age of mammals" just as accurately. 
Therefore, the correct answer is option C.

Reptiles had overcome the evolutionary hurdles of support and reproduction that limited the amphibians. Reptiles had strong ossified skeletons supported by advanced muscular systems for body support and locomotion. Some of the largest animals ever to live were dinosaurs of the Jurassic Period. Reptiles were also capable of laying amniotic eggs, which kept the developing young moist and nourished during gestation. This allowed for the first fully terrestrial animal life cycles. Dinosaurs may have been the dominant land animals, but they were not alone. Early mammals were mostly very small herbivores or insectivores and were not in competition with the larger reptiles. Adelobasileus, a shrew-like animal, had the differentiated ear and jaw bones of a mammal and dates from the late Triassic. Thus, option B is correct and other options are wrong.