Test: Evolution - 2 - NEET MCQ

• It is not adaptive radiation that confirms convergent evolution.
• It is an adaptive convergence that confirms convergent evolution.
• The remaining options are applicable to adaptive radiation.

An organism that lays 5 eggs, hatch the 5 eggs to reproduce 5 offspring can be considered as most evolved out of the other given condition. Least evolved organism lays more egg but produce only a few offspring.

Analogous organs are those organs which have the same function but are quite different in their fundamental structure and embryonic origin. For example, the wing of an insect and the wing of a bird are analogous organs. Both these organs are used for flying in the air but they re very different in structure. An insect wing is an extension of the integument whereas a bird wing is formed of limb bones covered with flesh, skin, and feathers. Each has evolved from a separate ancestral population as a means of a more efficient mode of locomotion. Similarity developed in distantly related groups as an adaptation for the same function is called analogy or convergent evolution.

Thus, the correct answer is option B. 

Topic in NCERT: Homology and divergent evolution

Line in NCERT: "though these forelimbs perform different functions in these animals, they have similar anatomical structure all of them have humerus, radius, ulna, carpals, metacarpals and phalanges in their forelimbs."

The earliest organisms that appeared on the earth were non-green and presumably anaerobes. The first autotrophic organisms were the chemo-autotrophs that never released oxygen. Both the statements are correct but reason does not explain the assertion.

Tasmanian tiger cat belongs to Australian marsupials. The remaining options belong to placental mammals. The Tasmanian tiger cat resembles bobcat of placental mammals. They show convergent evolution.

Oparin of Russia and Haldane of England proposed that the first form of life could have come from pre-existing non-living organic molecules (e.g. RNA, protein, etc.) and that formation of life was preceded by chemical evolution, i.e., formation of diverse organic molecules from inorganic constituents. The conditions on earth were – high temperature, volcanic storms, reducing atmosphere containing CH4 , NH3 , etc. In 1953, S.L. Miller, an American scientist created similar conditions in a laboratory scale. He created electric discharge in a closed flask containing CH4 , H2 , NH3 and water vapour at 8000C. He observed formation of amino acids. In similar experiments others observed, formation of sugars, nitrogen bases, pigment and fats.

The Hardy-Weinberg principle states that allelic and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences. There are five factors which are known to affect the equilibrium. These are gene flow, genetic drift, mutation, genetic recombination and natural selection. In population genetics, gene flow (also known as gene migration) is the transfer of alleles or genes from one population to another. Migration into or out of a population may be responsible for a marked change in allele frequencies (the proportion of members carrying a particular variant of a gene). Genetic drift (also known as allelic drift) is the change in the frequency of a gene variant (allele) in a population due to chance events. Genetic recombination is the production of offspring with combinations of traits that differ from those found in either parent. Mutation causes variations in the species, which influences the gene pool. Natural selection favours certain variations over others, resulting in an increase in allelic frequency of the favourable variations in the gene pool. Reproduction is a natural process in all organisms, which as such, does not affect Hardy-Weinberg equilibrium; it would be the genetic recombinations that arise from sexual reproduction, that affect it.

Topic in NCERT: Hardy-weinberg principle

Line in NCERT: "five factors are known to affect hardy-weinberg equilibrium. these are gene migration or gene flow, genetic drift, mutation, genetic recombination and natural selection."

Darwin finches and Australian marsupials are example of adaptive radiations as all the birds evolve from same birds having different beaks and Australian marsupials arise from common ancestors.

Topic in NCERT: Adaptive radiation

Line in NCERT: "darwin's finches represent one of the best examples of this phenomenon. another example is australian marsupials."

Wolf and Tasmania Wolf are examples of convergent evolution of placental mammals and Australian marsupials. They are evolved differently due to different in climatic and geographic regions.

Topic in NCERT: Adaptive radiation

Line in NCERT: "one can say that it is the similar habitat that has resulted in selection of similar adaptive features in different groups of organisms but toward the same function: kangaroo banded anteater marsupial rat."

When more than one adaptive radiation appeared in isolated geographical area it called a convergent evolution. Tiger cat, kangaroo, wombat and sugar gliders are example of Australian marsupials.

Homo sapiens arose in Africa and moved across continents and developed into distinct races during ice age between 75000-10000 years ago modern Homo sapiens arose.

Topic in NCERT: Origin and evolution of man

Line in NCERT: "homo sapiens arose in africa and moved across continents and developed into distinct races. during ice age between 75,000-10,000 years ago modern homo sapiens arose."

Common origin of man and chimpanzee is best shown by chromosomes. Both human beings and chimpanzee shows similar kinds of chromosome in terms of number and size.

Topic in NCERT: Comparative anatomy and morphology

Line in NCERT: "comparative anatomy and morphology shows similarities and differences among organisms of today and those that existed years ago."

Pre-historic man who gave proper burial to the dead for the first time was Neanderthal man of brain size 1400 cc lived in near east and central Asia about 100000 –40000 years back.

Topic in NCERT: Evolution of man

Line in NCERT: "the neanderthal man with a brain size of 1400cc lived in near east and central asia between 1,00,000-40,000 years back. they used hides to protect their body and buried their dead."

Homo habilis is a species of the tribe Hominini, during the Gelasian and early Calabrian stages of the Pleistocene period, between roughly 2.8 and 1.5 million years ago.

Homo erectus is an extinct species of hominid that lived throughout most of the Pleistocene geological epoch. Its earliest fossil evidence dates to 1.9 million years ago and the most recent to 70,000 years ago.

Homo sapiens is a common name that has been used to describe the first early modern humans.

Topic in NCERT: Evolution of life forms - a theory

Line in NCERT: "a rough sketch of the evolution of life forms, their times on a geological scale are indicated in (figures 6.9 and 6.10)."