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ISC Biology 2014 Class-12 Previous Year Question Papers

ISC Biology 2014 Class-12 Previous Year Question Paper Solved for practice. Step by step Solutions with Part-I, and II (Section-A,B and C). By the practice of ISC Biology 2014 Class-12 Solved Previous Year Question Paper you can get the idea of solving.

Try Also other year except ISC Biology 2014 Class-12 Solved Question Paper of Previous Year for more practice. Because only ISC Biology 2014 Class-12 is not enough for complete preparation of next council exam. Visit official website CISCE for detail information about ISC Class-12 Biology.

ISC Biology 2014 Class-12 Previous Year Question Papers Solved


-: Select Your Topics :-

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Part-I,

Sections-A, Part- II,

Sections-B, Part- II,

Sections-C, Part- II,


Maximum Marks: 70

Time allowed: Three hours

(Candidates are allowed additional 15 minutes for only reading the paper. They must NOT start writing during this time.)

  • Answer all questions in Part I and six questions in Part II, choosing two questions from each of the three sections A, B and C.
  • All working including rough work should be done on the same sheet as, and adjacent to, the rest of the answer.
  • The intended marks for questions or parts of questions are given in brackets [ ].

Part-I
(Attempt all questions)

ISC Biology 2014 Class-12 Previous Year Question Papers Solved

Question 1.
(a) Mention one significant difference between each of the following :
(i) Parenchyma and sclerenchyma.
(ii) Epistasis and dominance.
(iii) Hormones of ovulatory phase and hormones of luteal phase.
(iv) Symplastic movement and apoplastic movement.
(v) Phenotype and Genotype.

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(b) Give reasons for the following :
(i) Testes descend into the scrotum before birth.
(ii) Secondary growth does not occur in monocot stems.
(iii) Nitrogenous fertilizers are not applied in fields where leguminous crops grow.
(iv) Genetic code is ‘universal’.
(v) At higher temperatures, green plants start evolving CO2 instead of 02.

(c) Each of the following questions/statements has four suggested answers. Rewrite the correct answer in each case. [5]
(i) Typhoid is classified as a :
(A) Viral disease
(B) Genetic disorder
(C) Bacterial disease
(D) Protozoan disease

(ii) Bt cotton is resistant to :
(A) Insects
(B) Herbicides
(C) Salt
(D) Drought

(iii) Roots and shoots lengthen through the activity of:
(A) Apical meristem
(B) Vascular cambium
(C) Lateral meristem
(D) Cork cambium

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(iv) An antiviral protein released from infected and dying cells is :
(A) Antigen
(B) Antibody
(C) Antiserum
(D) Interferon

(v) Opening and closing of stomata is due to
(A) Ca2+
(B) Na+
(C) K+
(D) CL

(d) State the best-known contribution of: [3]
(i) Alec Jeffery
(ii) P.K. Sethi
(iii) Hugo de Vries

(e) Expand the following:
(i) SCID
(ii) ZIFT
Answer:
(a)

Parenchyma Sclerenchyma
(i) Fundamental soft plant tissue made-up of thin walled cells that forms the major part of leaves, roots, stem pith and fruit pulp. Mechanical strengthening or supportive plant tissue made-up of thick walled long cells or fibres and short cells sclereids.
Epistasis Dominance
(ii) In this two pairs of non-allelic genes are involved a gene pair inhibits the expression of another non-allelic gene. Out of a pair of alleomorphic genes, the one which appears in Fj generation, is called dominant and the phenomenon is called dominance.
Hormones of Ovulatory phase Hormones of Luteal phase
(iii) Estrogen and Luteinizing hormone bring about ovulation and causes a empty graafian follicle to develop into a corpus luteum which produces progesterone. Progesterone hormore stimulates the uterine lining development before implantation of a fertilized egg.
Symplastic movement Apoplastic movement
(iv) Water moves from cell to cell in the cytoplasm via the plasma membranes and plasmodesmata. Water moves from cell to cell via spaces in the outer cellulose cell walls.
Phenotype Genotype
(v) It is the externally observable charac­ters, controlled by genes It is the genetic constitution of an organism with regard to a character.

(b)

(i) Sperm formation requires a temperature which is few degree less than the normal body temperature. Scrotum has almost no fat insulation; so it keeps the testes at a cooler temperature. Also contraction or relaxation of muscles of scrotum moves the testes close to or far from heat of the body according to the environmental temperatures.

(ii) Secondary growth does not occur in monocot stem because it does not contain the meristematic tissue-cambium, which is responsible for secondary growth in plants. Vascular bundles are closed.

(iii) Nitrogenous fertilizers are not -needed in fields where leguminous crops grow because these plants have root nodules containing nitrogen fixing bacteria. They convert the nitrogen of soil air to nitrates which is used by these plants. The nitrates mix with the soil when these plants are ploughed under.

(iv) Genetic code is universal, triplet because it consist of three out of four nitrogenous bases-adenine, guanine, thymine and cytosine. These four bases in different triplet com-binations from all the various types of proteins, formed by genetic coding.

(v) At higher temperatures and high oxygen concentration, CO2 may be released by some plants instead of O2 because the main enzyme of photosynthesis -RuBP-carboxylase or Rubisco functions as RuBP-oxygenase. It splits RuBP into PGA and phosphoglycolic acid. The later is changed to glycolic acid and then to glycine. In the mitochondria, glycine forms serine and CO2, which is released. This process is called photorespiration. It undergoes photosynthesis.

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(c)

(i) Bacterial disease.
(ii) Insects.
(iii) Apical meristems.
(v) K+
(iv) Interferon.

(d)

(i) DNA fingerprinting.
(iii) Gave the term mutation.
(ii) Developed “Jaipur foot.

(e) (i) Severe Combined Immune Deficiency.
(ii) Zygote Intrafallopian Transfer.


Section-A Part-II (50 Marks)
(Answer any two questions)

ISC Biology 2014 Class-12 Previous Year Question Papers Solved

Question 2.
(a) Describe the Miller and Urey experiment on the origin of life. [3]
(b) Define the following : [2]
(i) Frame shift mutations.
(ii) Genetic drift.
Answer:
(a) Oparin-Haldane’s concept of biochemical basis of origin of life was put to a test by Stanley Miller and Harold C. Urey (1953) in laboratory by creating the probable conditions of primitive earth. They designed their apparatus of glass tubes and flasks as shown in the figure and created an atmosphere containing hydrogen, ammonia, methane and water vapour in one chamber of the apparatus and allowed condensed liquids to accumulate in another chamber. Energy was supplied by heating the liquid containing chamber as well as by electric sparks from electrodes in the gaseous chamber. The experiment was run continuously for a week and then they analysed the chemical composition of the liquid inside the apparatus. They found that the liquid contained a large number of complex organic compounds including some amino acids such as glycine, adenine and asparatic acid.
They designed their apparatus of glass tubes and flasks as shown in the figure and created an atmosphere containing hydrogen,

However, from the result of this experiment, they suggested that the electrical discharge, produced during lightening in the primitive atmosphere of earth containing hydrogen, ammonia, nitrogen and water vapour might have resulted in the formation of amino acids and other essential organic building blocks (sugars, nucleotides, etc.) of living organisms and possibly these could thus have formed life on the primitive earth. Thus, the experiment of Miller and Urey provides support for the biochemical concept of origin of life of Oparin and Haldane.

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