ISC Biology 2018 Class-12 Previous Year Question Papers

ISC Biology 2018 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 2018 Class-12 Solved Previous Year Question Paper you can get the idea of solving.

Try Also other year except ISC Biology 2018 Class-12 Solved Question Paper of Previous Year for more practice. Because only ISC Biology 2018 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 2018 Class-12 Previous Year Question Papers Solved

-: Select Your Topics :-


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)

  • This paper comprises TWO PARTS – Part I and Part II.
  • Part I contains one question of 20 marks having four sub parts.
  • Part II consists of Sections A, B and C.
  • Section A contains seven questions of two marks each Section B contains seven questions of three marks each, and
  • Section C contains three questions of five marks each.
  • Internal choices have been provided in two questions in Section A, two questions in Section B and in all three questions of Section C.
  • The intended marks for questions or parts of questions are given in brackets [ ].

Part-I (20 MARKS)

Previous Year Question Papers of ISC Biology 2018 Class-12 Papers Solved

Question 1.

(a) Answer the following questions briefly and to the point: [8 × 1] (i) Give a significant point of difference between Oestrous and Menstrual cycle.
(ii) Give the biological name of the organism causing typhoid.
(iii) If the haploid number of chromosomes in a plant species is 20, how many chromosomes will be present in the cells of the shoot tip?
(iv) Name a plant which flowers every twelve years.
(v) Name the diagnostic test for AIDS.
(vi) Name the terminal stage of ageing in the life cycle of plants.
(vii) Which organisms constitute the last trophic level?
(viii) What is emasculation?

(b) Each of the following questions has four choices. Choose the best option in each case :
(i) Length of the DNA with 23 base pairs is:
(1) 78.4 A
(2) 78.2 A
(3) 78 A
(4) 74.8 A

(ii) Opium is obtained from:
(1) Papaver somniferum
(2) Cannabis sativa
(3) Erythroxylum coca
(4) Datura metel

(iii) According to Abiogenesis, life originated from:
(1) Non-living matter
(2) Pre-existing life
(3) Oxygen
(4) Extra-terrestrial matter

(iv) The largest unit in which gene flow is possible is:
(1) Organism
(2) Population
(3) Species
(4) Genes

(c) Give one significant contribution of each of the following scientists: [4 × 1] (i) P. Maheshwari
(ii) E. Wilson
(iii) M. S. Swaminathan
(iv) H. Boyer

(d) Define the following: [2 × 1] (i) Biopatent
(ii) Parthenocarpy

(e) Give a reason for each of the following: [2 × 1] (i) Pollen grains of wind pollinated flowers are produced in large quantities.
(ii) Equilibrium of a forest ecosystem can be disturbed by uncontrolled hunting of big predators.
Answer 1.


Oestrous cycle Menstrual cycle
Occurs in non-primate mammals There is no blood flow.
Female allows mating only during heat
Occurs in primate mammals. Blood flow occurs.
Female always allow mating.

(ii) Salmonella typhi
(iii) 40 chromosomes
(iv) Strobilanthes kunthiana / Neelakuranji
(v) ELISA test/ Western blot test
(vi) Senescence
(vii) Decomposers
(viii) Emasculation is removal of anthers from bisexual flower before maturing for cross-fertilization.


(i) 78.2 A / 74.8 A
(ii) Papaver somniferum
(iii) Non-living matter
(iv) Species / population


(i) P. Maheshwari : Plant tissue culture
(ii) E. Wilson: Coined the term Biodiversity
(iii) M. S. Swaminathan: Green revolution in India
(iv) H. Boyer: Discovered restriction enzyme endonuclease.


(i) Biopatent: It is a legal right given to the owner for a biological discovery.
(ii) Parthenocarpy: Development of fruits without fertilization.


(i) Pollen grains of wind pollinated flowers are produced in large quantities because large number of pollen grains may be wasted on the way. It ensures pollination.
(ii) Equilibrium of a forest ecosystem can be disturbed by uncontrolled hunting of big predators as herbivore population will increase and disturb the food chain.

Section-A (14 Marks)

Previous Year Question Papers of ISC Biology 2018 Class-12 Papers Solved

Question 2.
(a) A woman with blood group O married a man with blood group AB. Show the possible blood groups of the progeny. List the alleles involved in this inheritance. [2] Or
(b) If the mother is a carrier of colour blindness and the father is normal, show the possible genotype and phenotype of the offspring of the next generation, with the help of a Punnet square.
Answer 2.
ISC Class 12 Biology Previous Year Question Papers Solved 2018 1
(i) Possible blood groups of the progeny: A and B
(ii) Alleles involved – IA, IB, 1O

ISC Class 12 Biology Previous Year Question Papers Solved 2018 2

(i) Phenotype: 25% of males colour blind, 75% progeny normal
(ii) Genotype: 50% Normal progeny, 25% Carrier female and 25% colour blind male

Question 3.
Define life span. Give the life span of an elephant. [2] Answer 3.
Life span is the time period from birth to death of an organism.
Life span of Elephant is between 20 – 90 years.

Question 4.
Give two characteristic features of each of the following: [2] (a) Ramapithecus
(b) Cro-Magnon man
Answer 4.
(a) Ramapithecus : Cranial capacity 600 – 700 cc and about 4 feet tall.
Bipedal locomotion with canines small, short face and small brain.
(b) Cro Magnon man: 1.8 m tall with erect posture.
Body less hairy, chin prominent, omnivores and cave dwellers.

Question 5.
(a) List any four effects of global warming. [2] Or
(b) State any four measures to control noise pollution.
Answer 5.
(a) Four effects of global warming:

– Mean temperature of earth increases
– Melting of ice caps and rise in sea level
– Coastal floods
– Extinction of large number of plant and animal species

(b) Four measures to control noise pollution:

– Use of better designed, quieter machine industries.
– Noisy industries should be away from residential areas.
– Enforce restriction on the use of loudspeakers and amplifiers.
– Plantation of trees on highways.

Question 6.
Define BOD. What is its significance in an aquatic ecosystem? [2] Answer 6.
BOD: (Biological Oxygen Demand) It is the amount of dissolved oxygen needed by aerobic organisms to breakdown organic material present in a given water sample.

Its significance in an aquatic ecosystem is that it indicates water pollution.

Question 7.
Give one significant difference between each of the following pairs : [2] (a) Humoral immunity and cell-mediated immunity.
(b) Benign tumour and malignant tumour.
Answer 7.
(a) Humoral immunity:
Consists of B-lymphocytes and is active against viruses and bacterias.

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