12th Class Biology Sample Paper

done Biology - Sample Paper-6 Total Questions - 27    [Download]

• question_answer1)
  What does movement of alleles into different gametes demonstrate?
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• question_answer2)

  Name the sex determination mechanism in followings.

  (i) Mammals

  (ii) Birds

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• question_answer3)
  Name two methane producing bacteria.
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• question_answer4)
  While doing a PCR, 'denaturation' step is missed. What will be its effect on the process?
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• question_answer5)
  Give the name of a selectable marker for E. coli.
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• question_answer6)

  Differentiate between linkage and recombination.

  OR

  Life originated from inorganic atom earlier but it is not possible today. Give reasons.

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• question_answer7)
  Name of man-made cereal? Trace how it was developed and where it is used?
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• question_answer8)
  You have chosen a plasmid as vector for cloning your gene. However this vector plasmid lacks a selectable marker. How would it affect your experiment?
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• question_answer9)

  (i) What is a parasitic food chain?

  (ii) What is the function of decomposers?

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• question_answer10)
  What is photochemical smog? How does smog effect biological world?
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• question_answer11)

  (i) Make a comparison between mammalian sperm and ovum.

  (ii) Explain the permanent methods of birth control

  OR

  What is polyembryony? Give two reasons of polyembryony.

   
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• question_answer12)
  Discuss Down's syndrome.
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• question_answer13)
  How chromosome number is maintained during sexual reproduction?
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• question_answer14)

  (i) Cleistogamy can favour only autogamy. Justify.

  (ii) Why emasculation is not required in unisexual flowers?

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• question_answer15)

  (i)  Discuss the Louis Pasteur's view about the origin of life.

  (ii) Define the following:

  (a) Gene frequency

  (b) Genetic drift.

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• question_answer16)
  Write an account of the original atmosphere on primitive earth.
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• question_answer17)
  Define operon. What is the organization of lac operon?
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• question_answer18)
  A mixture of fragmented DNA was electrophoresed in agarose gel. After staining the gel with ethidium bromide, no DNA bands were observed. What could be the reason?
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• question_answer19)

  (i)  How is bioreactor useful for production of desired products?

  (ii) How do we elute DNA of desired quality in gel electrophoresis?

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• question_answer20)
  What is accelerated eutrophication? Mention any two consequences of this phenomenon.
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• question_answer21)
  Write a note on fermentation by microbes and its applications.
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• question_answer22)

  (i) Mention the useful as well as harmful drug obtained from the latex of poppy plant.

  (ii) Write the name of plant from which morphine is obtained.

  (iii) Give the name of plant from which cocaine is obtained.

   
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• question_answer23)
  Explain diagrammatically the age structure of expanding, stable and declining population.
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• question_answer24)
  Nidhi attended a seminar on the topic "How to minimise the use of plastic bags to reduce environmental pollution?" In evening she goes to a market with her mother and carried a natural fibre carry bag for shopping and decline to take good items in polythene bags.

  (i) Do you think Nidhi's action is eco-friendly. Justify.

  (ii) How the use of polythene causes environmental pollution?

  (iii) Compare biodegradable and non-biodegradable pollutants.

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• question_answer25)

  Discuss the various chemical methods of controlling human population.

  OR

  What do you mean by gametogenesis? Describe the structure of a human sperm.

   
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• question_answer26)

  Show that Darwin's natural selection is based on natural observation, with an example for each.

  OR

  Explain Meselson and Stahl's experiment to prove semiconservative DNA replication.

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• question_answer27)

  (i)  Which microbes are responsible for producing following products?

  (a) Bread

  (b) Swiss cheese

  (c) Penicillin

  (d) Statin

  (e) Streptokinase

  (ii) Explain, how are microbes important for humans?

  OR

  If your family owned a dairy farm, what measures would you undertake to improve the quality and quantity of milk production?

   
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