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Question 6, , Single Answer, , 2.00 marks, , The different forms of interbreeding species that, live in different geographical reg ions are called a~, , D, , A. Sibling species, , D, , B. Sympatric species, , m C. Allopatric species, D, , D. Polytypic species, , D, , E. Monotypic species
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Solution, Allopatric species are species occupying, separate, non-overlapping geographic areas, and are unavailable for, interbreeding. Allopatric speciation, is the, most common form of speciation. When, populations of a species become separated,, gene flow between them ceases. Over time,, the populations may become genetically, different in response to the natural selection, imposed by their different, environments.Sibling species are any of two, or more related species that are, morphologically nearly identical but are, incapable of producing fertile hybrids., Sympatric speciation i's the process through, w .h ich new species evolve from a single, ancestral species while inhabiting the same, geographic region. A polytypic genus, contains two or more different species, while, a polytypic species consists of two or more, subspecies. A monotypic genus contains a, si1, n gle species, while a, monotypic species, consists of a single population that is not, divided into subspecies., Thus, the correct answer is option C.
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Question 7, , 2.00 marks, , Single Answer, , Which of t he following is correct?, , D, , A. A. I. Oparin proved Stan ley M iller's theory, about origin of life., , m 8. Stanley Miller proved A. I .Oparin s theory, 1, , about origin of life., , D, , C. Stan ley Mill er proved A. C. Urey's theory, about origin of life., , D, , D. J . B. S. Haldane proved A. I. Oparin's, theory about origin of life., , ✓ Correct, , Solution, , According to Haldane and Oparin, the organic, molecules could be for med from abiogenic, materials in the presence of an external, energy source in the primitive atmosphere. In, 1953, American chemists Harold C. Urey and, Stanley Miller tested the Oparin-Haldane, theory and successfully produced amino, acids from some of the inorganic, components thought to have been present on, probiotic Earth and is called as the Miller-Urey, experiment. In this experiment, the warm, , water is mixed with four gases like water, vapour, methane, ammonia, and molecular, hydrogen and pulsed the atmosphere with, electrical discharges. Thus, option B is, correct.
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Question 8, , Single Answer, , 2.00 marks, , The possible det ails of a chemical evolution of, t he m ost element ary forms of lif e was particu lar!:, well-worked out experi menta lly by, , D, , A. Haldane, , 0, , B. Sydney W. Fox, , m C. Urey and Miller, 0, , D. A. I. Oparin
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Solution, , The Miller Urey experiment was a chem1ical, experiment that simulated the conditions, thought at the time to be present on the early, Earth and tested the chemical origin of life., Specifically, the experiment tested Alexander, Oparin's and J. B. S. Haldane's hypothesis, (that is the modern theory of origin of life), that conditions on the primitive Earth, favoured chemical reactions that synthesize, more complex organic compounds from, simpler inorganic precursors. Considered to, be the classic experiment investigating, abiogenesis, it was conducted in 1952 by, Stanley Miller, under the supervision of Harold, Urey, at the University of Chicago and later the, University of California, San Diego and, published the following year. The experiment, used water (H 2 0), methane (CH 4 ), ammonia, (NH3), and hydrogen (H2). Next, they ran a, continuous electric current through the, system, to simulate lightning storms believed, to be common on the early earth. Analysis of, the experiment was done by chromatography., At the end of one week, Miller observed that, as much as 10-15% of the carbon was now in, the form of organic compounds. Two percent, of the carbon had formed some of the amino, acids. which are used to make proteins., Perhaps most importantly, Miller's experiment, showed that organic compounds such as, amino acids, which are essential to cellular
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Question 9, , Single Answer, , 2.00 marks, , Life took ............... ... to develop from protocells tc, primitive PPLO (bacteria type cell)., , 0, , A. Four bi llion years, , 0, , 8. Five billion years, , m C. One billion years, D, , D. Th ree billion yea rs
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✓, , Correct, Solution, , Chemosynthesis of self replicating nucleic, acids and proteins followed by aggregation of, proteins around nucleic acid resulted in origin, of first life form. Also known as protovirus,, eobiont or protocell, the first life forms were, membrane enclosed sac of molecules that, had ability to concentrate material, capture, energy, carry out metabolism and to replicate, the genetic material (RNA served as both, genetic materials and enzymes in primitive, life forms). Evolution of protocell into first, bacteria like cell involves appearance of, central region containing self replicating DNA,, replication and transcription machinery,, evolution of ribosomes and protein, synthesizing machinery, mechanism of, division to distribute the replicated DNA to, daughter cells enclosed by a selectively, permeable membrane. The above mentioned, changes occupied more than one billion years, from earth's origin 4.6 billion years ago to, appearance of first prokaryotic cell around, 3.5 billion years ago., Therefore, the correct answer is option C.
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Question 10, , Single Answer, , 2.00 marks, , Some comp lex inorganic and orga nic compound!, in the hot sea aggregated in different, combi nations to form, , D, , A. Protoplasm, , 0, , B. Cytoplasm, , 0, , C. Nucleus, , L'I, , D. Coacervates
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Solution, , The Precambrian is the largest span of time, in Earth's history before the current, Phanerozoic Eon, and is a Supereon divided, into several eons of the geologic time scale. 11, spans from the formation of Earth about 4.6, billion years ago to the beginning of the, Cambrian Period, about 541.0 1.0 million, years ago, when hard-shelled creatures first, appeared in abundance. The Precambrian is, so named because it precedes the Cambrian,, the first period of the Phanerozoic Eon, which, is named after Cambria, the classical name, for Wales, where rocks from this age were, first studied. The Precambrian accounts for, 88% of geologic time. All life-forms were long, assumed to have originated in the Cambrian,, and therefore all earlier rocks were grouped, together into the Precambrian. Although, many varied forms of Iife evolved and were, preserved extensively as fossil remains in, Cambrian sedimentary rocks, detailed, mapping and examination of Precambrian, rocks on most continents have revealed that, additional primitive life-forms existed more, than 3.4 billion years ago. Nevertheless, the, original terminology to distinguish, Precambrian rocks from all younger rocks is, still used for subdividing geologic time. Thus,, option C is correct. Life is not originated in, Proterozoic era, Mesozoic era and Coenozoic, era. Thus, other options are wrong.
