Multiple Choice Questions

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The plant part which consists of two generations, one within the other, is

  • genninated pollen grain

  • embryo

  • unfertilized ovule

  • seed


D.

seed

Seed develops from an ovule (consisting integument and nucellus) or megasporangium. Parts of ovule develop a haploid megaspore which grow into haploid female gametophyte. This female gametophyte develops an egg or oospore. The latter is fertilized by a male gamete and develops into a zygote (2n). The zygote develops into an embryo or new sporophyte. The embryo (2n) is surrounded by the female gametophyte (n), the latter by seed coat (2n). In this way, seed contains three generations locked one within another. Of these, two generations occur within embryo.


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Assertion : Inhabitants close to very busy airports are likely to experience health hazards.

Reason : Sound level of jet aeroplanes usually exceeds 160 dB.

  • If both Assertion and Reason are true and the reason is the correct explanation of the assertion

  • If both Assertion and Reason are true but the reason is not the correct explanation of the assertion

  • If Assertion is true statement but Reason is false

  • If both Assertion and Reason are false statements


Assertion : All birds, except the ones like koel (cuckoo) build nests for retiring and taking rest during night time (day time for nocutrnal).

Reason : Koel lays its eggs in the nests of tailor bird.

  • If both Assertion and Reason are true and the reason is the correct explanation of the assertion

  • If both Assertion and Reason are true but the reason is not the correct explanation of the assertion

  • If Assertion is true statement but Reason is false

  • If both Assertion and Reason are false statements


Assertion : Old age is not an illness. It is a continuation of life with decreasing capacity for adaptation.

Reason : Cessation of mitosis is a normal genetically programmed event.

  • If both Assertion and Reason are true and the reason is the correct explanation of the assertion

  • If both Assertion and Reason are true but the reason is not the correct explanation of the assertion

  • If Assertion is true statement but Reason is false

  • If both Assertion and Reason are false statements


Assertion : In plant tissue culture, somatic embryos can be induced from any plant cell.

Reason : Any viable plant cell can differentiate into somatic embryos.

  • If both Assertion and Reason are true and the reason is the correct explanation of the assertion

  • If both Assertion and Reason are true but the reason is not the correct explanation of the assertion

  • If Assertion is true statement but Reason is false

  • If both Assertion and Reason are false statements


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Assertion : Many visitors to the hills suffer from skin and respiratory allergy problem.

Reason : Conifer trees produce a large quantity of wind-borne pollen grains.

  • If both Assertion and Reason are true and the reason is the correct explanation of the assertion

  • If both Assertion and Reason are true but the reason is not the correct explanation of the assertion

  • If Assertion is true statement but Reason is false

  • If both Assertion and Reason are false statements


Assertion : Yeasts such as Saccharomyces cerevisiae are used in baking industry.

Reason : Carbon dioxide produced during fermentation causes bread dough to rise by thermal expansion.

  • If both Assertion and Reason are true and the reason is the correct explanation of the assertion

  • If both Assertion and Reason are true but the reason is not the correct explanation of the assertion

  • If Assertion is true statement but Reason is false

  • If both Assertion and Reason are false statements


Assertion : In a food chain members of successive higher levels are fewer in number.

Reason : Number of organisms at any trophic level depends upon the availability of organisms which serve as food at the lower level.

  • If both Assertion and Reason are true and the reason is the correct explanation of the assertion

  • If both Assertion and Reason are true but the reason is not the correct explanation of the assertion

  • If Assertion is true statement but Reason is false

  • If both Assertion and Reason are false statements


Assertion : Tropical rain forests are disappearing fastly from developing countries such as India.

Reason : No value is attached to these forests because these are poor in biodiversity.

  • If both Assertion and Reason are true and the reason is the correct explanation of the assertion

  • If both Assertion and Reason are true but the reason is not the correct explanation of the assertion

  • If Assertion is true statement but Reason is false

  • If both Assertion and Reason are false statements


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Drinking of mineral water with very low level of pesticides (about 0.02 ppm) for long periods may:

  • produce immunity against mosquito

  • cause leukemia (blood cancer) in most people

  • cause cancer of the intestine

  • lead to accumulation of pesticide residues in body fat