ISC Biology 2017 Class-12 Previous Year Question Papers

ISC Biology 2017 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 2017 Class-12 Solved Previous Year Question Paper you can get the idea of solving.

Try Also other year except ISC Biology 2017 Class-12 Solved Question Paper of Previous Year for more practice. Because only ISC Biology 2017 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 2017 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 (20 Marks)

ISC Biology 2017 Class-12 Previous Year Question Papers Solved

Question 1.
(a) Give a brief answer for each of the following: [4]
(i) Why do Green plants start evolving CO2 instead of O2, at high temperatures?
(ii) Define Apomixis.
(iii) What is a Recon?
(iv) Why are the spores of Bacillus thuringiensis used as bioinsecticide?

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(b) Each of the following question(s)/statement(s) has four suggested answers. Choose the correct option in each case. [4]
1. Initiation codon of protein synthesis in Eukaryotes is:
(i) GUA
(ii) GGA
(iii) CCA
(iv) AUG

2. Type of Interaction where an individual sacrifices its own welfare (life) for the benefit of another animal of its own species is:
(i) Altruism
(ii) Scavenging
(iii) Protocooperation
(iv) Commensalism

3. Wings of Insect and Birds are examples of:
(i) Analogous
(ii) Homologous
(iii) Vestigial
(iv) Atavism

4. The pressure of the cell contents on the cell wall is known as:
(i) Wall pressure
(ii) Osmotic pressure
(iii) Turgor pressure
(iv) Diffusion pressure

(c) Give a scientific term for each of the following: [4]
(i) An act of expelling the full term foetus from mother’s uterus at the end of gestation.
(ii) Entry of pollen tube into an ovule through integuments.
(iii) An alternative form of the single gene which influences the same character and produces different expressions in different individuals of.a species.
(iv) The study of human population covering all aspects and parameters.

(d) Expand the following abbreviations : [4]
(i) MTP
(ii) IW
(iii) HIV
(iv) DPD

(e) Name the scientists who have contributed to the following: [4]
(i) Discovered the fossil of Cro-Magnon man.
(ii) Classified active and passive absorption of water by roots.
(iii) Reported Haemophilia.
(iv) Discovered double fertilization.
Answer:
(a) (i) It is due to photorespiration. The green cells in the presence of light, take-up oxygen and produce CO2, without yielding any useable energy.
(ii) Apomixis is a type of asexual reproduction which mimics sexual reproductive i.e. production of seeds without pollination and fertilization.
(iii) Recon is the small segment of DNA which can undergo recombination.
(iv) Spores of Bacillus thuringiensis contain toxic cry proteins also called Bt-toxin which kill larvae of insects.

(b)
1. – (iv) AUG .
2. – (ii) Altruism
3. – (i) Analogous
4. – (iii) Turgor pressure

(c)

(i) Parturition
(ii) Mesogamy
(iii) Allele
(iv) Demography

(d)

(i) Medical Termination of Pregnancy
(ii) In-Vitro Fertilization
(iii) Human Immunodeficiency Virus
(iv) Diffusion Pressure Deficit.

(e)

(i) Edward Lartet (1868)
(ii) Kramer (1949)
(iii) John Otto (1803)
(iv) Nawaschin (1898)


Sections-A, Part- II,

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ISC Biology 2017 Class-12 Previous Year Question Papers Solved

Question 2.
(a) Differentiate between Apes and Man with respect to the following characteristics:
(i) Posture
(ii) Brow ridges
(iii) Cranial capacity
(b) Define protobionts. [1] (c) What is cognogeny? [1] Answer:
(a)

(i) Semi-erect posture Completly erect posture
(ii) Brow ridge prominent Brow ridges weakly developed
(iii) Cranial capacity 100-500 cm3
(iv) Cranial capacity 1400-1450 cm3

(b) Protobionts have various types of chemicals like proteins, nucleic acids, carbohydrates, etc., enclosed inside a lipid membrane an<f proteins got associated with the membrane covering of protobionts.
(c) Cognogeny : It refers to the evolution of different life forms on this planet-the Earth.

Question 3.
(a) Explain any three molecular (genetic) evidences in favour of organic evolution. [3] (b) Define biogenesis. [1] (c) Define fossils. [1] Answer:
(a)

(i) All organisms have cellular structure and DNA is the genetic material, indicating their common ancesting except RNA virus.
(ii) Genetic information flow from DNA to RNA to protein, a phenomenon called Central Dogma.
(iii) Mutations are the source of new variations and fountain head of evolution.
(iv) Genetic information is stored in the DNA in the form of sequence of nucleotides. Genetic code is a triplet code. It is same from bacteria to humans (any three points).

(b) The phenomenon of biogenesis states that living beings are neither produced spontaneously, nor created. Instead life comes from pre-existing life.
(c) Fossils are the remains, tracks, impressions or traces of organisms that existed in the past.

Question 4.
(a) List any three drawbacks of Darwinism. [3] (b) State Hardy-Weinberg’s principle. [1] (c) Differentiate between Directional natural selection and Disruptive natural selection. [1] Answer:
(a) Drawbacks of Darwinism : .
(i) Though his theory is based on the presence of variations, he could not explain the origin of variation nor could he attach any importance to mutations.
(ii) Darwin could not explain the origin of new characters. It only provide mechanism of modification of already existing characters.
(iii) Over specialised organs are those which have grown beyond their maximum usefulness. They have become a hindrance for the animal, e.g., branched antlers of deer, tusk of elephant, etc.

(b) All the genes and their alleles found in an interbreeding population is called gene pool. Normally, the alleles tend to maintain an equilibrium with reference to one another oyer the generation irrespective of the phenotypic expression. It is called genetic equilibrium. A change in relative frequency of alleles brings about evolution.
(c) If the selection favours small or large sized individuals, more individuals of that type will be present in the next generation. With continued selection over generation mean size of the population would have changed it. It is directional selection which brings about evolution in the population. In the natural selection, both small size and long sized individuals, natural selection would be disruptive type. It produces two peaks in the distribution of trait that may lead to the development of two different population.

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