31 Years NEET Previous Year Questions: Evolution - 2 - Year 12 MCQ

These areas are geographically isolated from other continents by the oceanic barrier which has prevented uniform distribution of fauna.

In 5000 years a given amount of radioactive carbon would decay to half initial concentration.

Homologous organs are those organs, which have the same origin and similar basic structure but may differ in external appearance and function. Wings of birds and pectoral fins of fishes are an example of the homologous organs.

Water is an essential constituent of cytoplasm of all living organisms it helps in distribution of substances within the organism elimination of waste products, body temperature maintenance etc. It is absent on moon. Anaerobic organisms can live in the absence of O₂. Light and temperature are already known to exist on moon.

rRNA occurs in side ribosomes and involved in protein synthesis, mRNA brings coded information from DNA to form polypeptides. tRNA takes part in transferring amino acids from cellular pool to episomes for polymerization to form polypeptides.
Carl Woese gave the theory of life based on his discovery that the genes encoding ribosomal RNA are ancient and distributed over all lineages of life with little or no gene transfer. Therefore rRNA are commonly used to infer phylogeny.

The Mesozoic era is the era during which reptiles were dominant. It includes three periods: Triassic (240 million years ago), Jurassic (195 million years ago) and Cretaceous (135 million years ago). Origin of dinosaurs occurred during the triassic period. During the Jurassic period, lizards, crocodiles and alligators originated. Dinosaurs became large and reptiles were dominant during this period. During the cretaceous period, dinosaurs got extinct.

Gause's hypothesis states that two different competing species cannot coexist together for a long in the same niche, one has to get eliminated by the other competing species, if they do coexist, then they do so as a result of niche differentiation, i.e. differentiation of then realized niches.

The phenomenon of development of a new species from pre-existing one is called speciation. Reproductive isolation is the prevention of interbreeding between the populations of two different species. It maintains the characters of the species but can lead to the origin of new species.

Africa is often called as the cradle of man.

Mutation is any random sudden heritable change occurring in the genetic material. Sexual selection refers to selection of a mate by an organism.

In human cells, chromosomes are present in both nucleus as well as mitochondria. Most of the proteins in humans are encoded by the nuclear genome but mitochondrial DNA plays a significant role too. Mitochondria contain their own DNA that is separate from the nuclear DNA. mtDNA shows maternal inheritance. The nuclear DNA which is equally inherited from both the mother and the father, mitochondrial DNA (mtDNA) is inherited only from the mother. This makes mitochondrial DNA particularly interesting and useful for human evolutionary studies. Normally, mtDNA is identical to that of the mother. But like all DNA molecules, mtDNA molecules also undergo mutations that change the sequence slightly. Thus, mtDNA of a daughter cell would be different from the mtDNA of its mother and this difference is proportional to the amount of time that has passed and therefore proves to be very useful for studying human evolution. Similar is the case with Y chromosome that is inherited from the father and, therefore, follows a similar evolutionary pattern like mtDNA.

So, the correct answer is option C.

According to Darwinism there is differential reproduction, followed by struggle for existence, suitable variations are selected by nature-natural selection.

The replacement of grey coloured moth by dark coloured melanic species due to industrial smoke is called industrial melanism. Initially on the lichen covered tree trunks, the mutant moths was more conspicuous due to its black colouration and was therefore more susceptible to predation by birds. The large scale burning of coal during industrial revolution resulted in the deposition of sooty particulate matter on tree trunks. Hence the grey coloured moths became more conspicuous to predatory birds. Thus the population of black moths  increased considerably. 

Migration refers to the movement of individuals into and out of population. Mutation refers to random and sudden heritable variations or changes arising in the genetic constitution.

Independent formation of functionally similar structures by unrelated organism is called convergent evolution.

Those organs which have a common origin and are built on the same anatomical pattern, but perform different functions and are modified accordingly. 

In any population , there is always competition for space and food resources. 

Genetic drifts occurs only in small isolated population.

Amphibians have moved onto terrestrial habitat  but they still need to go back to water for reproduction. The presence of gills in tadpole indicate that amphibians have evolved from fishes. Fishes are completely aquatic so the other three options are incorrect.

DNA from sex chromosomes, autosomes and mitochondria reflect the entire genomic limit. Chromosome morphology is only partial.

ESR, Electron Spin Resonance measures number of charges occupying deep traps in crystal band gap.
Electron Paramagnetic Resonance (EPR) or Electron Spin Resonance (ESR) is a spectroscopic technique which detects species that have unpaired electrons, generally meaning that the molecule in question is a free radical if it is an organic molecule, or that it has transition metal ions if it is an inorganic complex. Because most stable molecules have a closed-shell configuration without a suitable unpaired spin, the technique is less widely used than nuclear magnetic resonance (NMR). The EPR was first discovered in Kazan State University by Soviet physicist Yevgeniy Zavoyskiy in 1944

According to Oparin, the atmosphere of calmative earth was reducing because its atoms were most numerous  and most reactive. Free oxygen was not present in significant amount.
Large quantities  of H₂, N₂, water vapour, CO₂, CH₄ and NH₃ were present.

Electron Spin Resonance method is the most accurate method for dating of fossils.

Animals resist predation by cryptic coloration deceptive marking, behavioural defenses and possession of mechanical or chemical defenses. Examples are colour change in Chameleon Enlargement of body size by swallowing air in potter fish, Melanism in moths. 

Human evolution is a subject of ongoing debate among scientists, who employ various methods such as studying DNA and RNA fragments, fossils, and mitochondrial DNA to establish relationships among different organisms. Approximately 2 million years ago, humans embarked on their first migration out of Africa into Asia, followed by entry into Europe between 1.5 million and 1 million years ago. Over the course of many years, modern humans spread across various parts of the world, with the migration to Australia believed to have occurred around 60,000 years ago. The advent of agriculture and the rise of the first civilizations are thought to have taken place around 12,000 years ago. Recent experiments focusing on the mitochondrial DNA of different species, including humans, have provided global evidence supporting the idea that all human races share a common origin in Homo sapiens, whose ancestors originated in Africa.Thus there is greater variation in Asia than in Africa.