Test: Evolution of Life Forms & Evidences of Evolution (December 19) - NEET MCQ

“Ontogeny recapitulates Phylogeny”  known as “Ontogeny repeats Phylogeny” is a heredity theory given by Ernst Haeckel.

Ontogeny refers to the predecessors or the ancestral genetic characters.

Phylogeny is the genetic combinations of the future generations.

Hence, the theory means that The characteristics or traits shown by the future generations are the repeatations or recapitulations of the traits of the ancestry.

Paleontology is the branch of biology that studies the forms of life that existed in former geologic periods, mainly by studying fossils. It is the study of the history of life on earth, as reflected in the fossil record. Fossils are the remains or traces of organisms (plants, animals, fungi, bacteria and other single-celled living things) that lived in the geological past and are preserved in the crust of the earth. 

• It was from the seed-eating finches, many other altered forms of beak arose enabling them to be insect, cactus or fruit eaters.
• This led to the discovery of Adaptive radiation.
• Darwin’s finches are one of the best examples of this process.

Lycaenops was a mammal-like reptile. It is considered a missing link between reptiles and mammals. Laying shelled eggs is a characteristic of birds and reptiles. Having hair, teats on body and cloaca are characteristics of animals. So, particular animal has shelled eggs, hair and teats on the body and has cloaca, it may be a connecting link between reptiles and mammals. Thus, option C is correct and other options are wrong.

Homologous organs are structures or organs of different animals that evolved from a common ancestor (similar developmental origin) but differ in their functions. On the other hand, analogous organs are structures that evolved independently (different developmental origin) in two different species of organisms to serve a similar function. The wings of a butterfly and a bird have a similar function of flying but they are anatomically different in origin.

If a starfish possess 6 arms instead of 5, it is an example of variation [variation is any difference between cells, individual organisms, or groups of organisms of any species caused either by genetic differences (genotypic variation) or by the effect of environmental factors on the expression of the genetic potentials (phenotypic variation)]. Variation may be shown in physical appearance, metabolism, fertility, mode of reproduction, behaviour, learning and mental ability and other obvious or measurable characters. Metamorphosis is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Biogenesis is the production of new living organisms or organelles and evolution is change in heritable traits of biological populations over successive generations.

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 419.2 3.2 Mya, to the beginning of the Carboniferous Period, about 358.9 0.4. 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 Fish". 

Therefore, the correct answer is option A.

The Rocky Mountains took shape during an intense period of plate tectonic activity that resulted in much of the rugged landscape of the western North America. The Laramide orogeny, about 80–55 million years ago, was the last of the three episodes and was responsible for raising the Rocky Mountains.The Mesozoic Era lasted nearly 200 million years, starting and ending with mass extinctions. This era consisted of the Triassic, Jurassic, and Cretaceous Periods. The Mesozoic is thought to have had a warm climate that dinosaurs thrived in for 135 million years.

Fossilization occurs after an organism dies and only affects hard body parts, such as bones and shells. Soft flesh, scales, and feathers will not become fossils, although, imprints of these parts are sometimes made. In order for fossilization n to occur three things must happen. First, an organism dies.