NCERT Exemplar MCQ

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(b) Lichens are sensitive to \(\mathrm{SO}_2\) pollution. Lichens are very good pollution indicators, they do not grow in polluted areas.

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(c)
– For a long time it was also believed that life came out of decaying and rotting matter like straw, mud, etc.
– According to theory of abiogenesis, life originates from non-living.

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(b) Animal husbandry and plant breeding programmes are the examples of artificial selection.

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(c) Palaeritological evidences for evolution refer to the fossils. Fossils provide direct and solid evidence in favour of organic evolution through ages. Fossils are studied for knowing about extinct organisms. Birbal Sahni Institute of Palaeobotany is situated at Lucknow. Birbal Sahni is called ‘Father of Indian Palaeobotany’. Age of fossils is determined by Uranium-Lead method \(\left(U^{238}\right)\) or Potassium-Argon method or Radioactive Carbon dating \(\left(\mathrm{C}^{14}\right)\). ESR (electron-spin-resonance method) is the most accurate method of dating of fossils.

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(b) Organs having same origin but different functions are called homologous organs. For example, whales, bats, Cheetah and human (all mammals) share similarities in the pattern of bones of forelimbs.
Homology indicates common ancestry.

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(d) Organs having different origin but similar function are called analogous. Wings of butterfly and of birds look alike. They are not anatomically similar structures though they perform similar functions.
Hence, analogous structures are a result of convergent evolution (different structures evolving for the same function and hence having similarity).

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(a) \((p+q)^2=p^2+2 p q+q^2=1\) represents an equation used in population genetics.
Above equation is known as Hardy-Weinberg principle in which
\(p^2\)-Dominant homozygous
2pq – Heterozygous
\(q^2-\) Recessive homozygous

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(c) Appearance of antibiotic-resistant bacteria is an example of pre-existing variation in the population.

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(d) Evolution of life shows that life forms had a trend of moving from water to land.

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(c) Viviparity is considered to be more evolved because the young ones are protected inside the mother’s body and are looked after they are bom leading to more chances of survival.

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(a) Fossils are generally found in sedimentary rocks.

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(a) : According to Hardy-Weinberg principle, the expected frequency of MN – blood group bearing organism is likely to be CBSELabs.com

\(
\begin{aligned}
& p^2+2 p q+q^2=1 \\
& 49+.09+2 x=1 \\
& 58+2 x=1 \\
& 2 x=1-59 \\
& =42 \%
\end{aligned}
\)

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(c) Ramapithecus \(\rightarrow\) > Homo habilis \(->\) Homo erectus \(->\) Homo sapiens

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(d) Chimpanzee is an example for link species.

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(b) Directional type of selection is industrial melanism observed in moth, Bistonbitularia.

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(b)

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(d) In 1953 S. L. Miller created primitive earth conditions in the laboratory and gave experimental evidence for origin of first form of life from pre-existing non-living organic molecules. The primitive earth conditions created include high temperature, volcanic storms, reducing atmosphere containing \(\mathrm{CH}_4\), \(\mathrm{NH}_3\) etc.

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(a) Variations during mutations of meiotic recombinations are random and direction less.