CBSE Class 12 Biology 2017 board exam question paper (All India, Set 1, and Code Number 57/1) is available here. The paper was held today on 5 April 2017. With this article, students can download the complete CBSE Class 12 Biology 2017 board exam question paper in PDF format. With the help of this paper, students can easily understand the level of questions which are CBSE Class 12 Biology board exam 2017.
About CBSE Class 12 Biology 2017 Board Exam Paper
Total 31 questions are present in this paper. These questions are divided into 5 sections i.e., Section A, B, C, D and E. Out of 31 questions, only 26 questions need to be attempted. There is no overall choice in the question paper. However, internal choices are present in some question.
General Instructions given in the paper
Time allowed: 3hours Maximum Marks: 70
There are a total of 26 questions and five sections in the question paper.
All questions are compulsory.
Section - A contains question number 1 to 5, Very Short Answer type questions of one mark each.
Section - B contains question number 6 to 10, Short Answer type I questions of two marks each.
Section - C contains question number 11 to 22, Short Answer type II questions of three marks each.
Section - D contains question number 23, Value Based Question of four marks.
Section - E contains question number 24 to 26, Long Answer type questions of five marks each.
There is no overall choice in the question paper; however, an internal choice is provided in one question of two marks, one question of three marks and all three questions of five marks. An examinee is to attempt any one of the questions out of the two given in the question paper with the same question number.
Question 1: Name the type of cross that would help to find the genotype of a pea plant bearing violet flowers.
Question 2: State two postulates of Oparin and Haldane with reference to origin of life.
Question 3: A herd of cattle is showing reduced fertility and productivity. Provide one reason and one suggestion to overcome this problem.
Question 4: What are Cry genes? In which organism are they present?
Question 5: An electrostatic precipitator in a thermal power plant is not able to generate high voltage of several thousands. Write the ecological implication because of it.
Question 6: A pollen grain in angiosperm at the time of dehiscence from an anther could be 2-celled or 3-celled. Explain. How are the cells placed within the pollen grain when shed at a 2-celled stage?
Question 7: Differentiate between the genetic codes given below:
(a) Unambiguous and Universal
(b) Degenerate and Initiator
Question 8: Mention one application for each of the following :
(a) Passive immunization
Question 9: Name the microbes that help production of the following products commercially :
(b) Citric acid
(d) Butyric acid
Question 10: List four benefits to human life by eliminating the use of CFCs.
Suggest two practices giving one example of each that help protect rare or threatened species.
Question 11: (a) Can a plant flowering in Mumbai be pollinated by pollen grains of the same species growing in New Delhi? Provide explanations to your answer.
(b) Draw the diagram of a pistil where pollination has successfully occurred. Label the parts involved in reaching the male gametes to its desired destination.
Question 12: Both Haemophilia and Thalassemia are blood related disorders in humans. Write their causes and the difference between the two. Name the category of genetic disorder they both come under.
Question 13: (a) List the two methodologies which were involved in human genome project. Mention how they were used.
(b) Expand ‘YAC’ and mention what was it used for
Question 14: Write the characteristics of Ramapithecus, Dryopithecus and Neanderthal man.
Question 15: Name a human disease, its causal organism, symptoms (any three) and vector, spread by intake of water and food contaminated by human faecal matter.
(a) Why is there a fear amongst the guardians that their adolescent wards may get trapped in drug/alcohol abuse ?
(b) Explain ‘addiction’ and ‘dependence’ in respect of drug/alcohol abuse in youth.
Question 16: (a) Write the desirable characters a farmer looks for in his sugarcane crop.
(b) How did plant breeding techniques help north Indian farmers to develop cane with desired characters ?
Question 17: Secondary treatment of the sewage is also called Biological treatment.
Justify this statement and explain the process.
Question 18: (a) Explain the significance of ‘palindromic nucleotide sequence’ in the formation of recombinant DNA.
(b) Write the use of restriction endonuclease in the above process.
Question 19: Describe the roles of heat, primers and the bacterium Thermus aquaticus in the process of PCR.
Question 20: Explain the various steps involved in the production of artificial insulin.
Question 21: (a) ‘‘Organisms may be conformers or regulators.’’ Explain this statement and give one example of each.
(b) Why are there more conformers than regulators in the animal world ?
Question 22: Describe the inter-relationship between productivity, gross primary productivity and net productivity.
Question 23: It is commonly observed that parents feel embarrassed to discuss freely with their adolescent children about sexuality and reproduction. The result of this parental inhibition is that the children go astray sometimes.
(a) Explain the reasons that you feel are behind such embarrassment amongst some parents to freely discuss such issues with their growing children.
(b) By taking one example of a local plant and animal, how would you help these parents to overcome such inhibitions about reproduction and sexuality?
Question 24: (a) When a seed of an orange is squeezed, many embryos, instead of one are observed. Explain how it is possible.
(b) Are these embryos genetically similar or different? Comment.
(a) Explain the following phases in the menstrual cycle of a human female:
(i) Menstrual phase
(ii) Follicular phase
(iii) Luteal phase
(b) A proper understanding of menstrual cycle can help immensely in family planning. Do you agree with the statement? Provide reasons for your answer.
Question 25: (a) Compare, giving reasons, the J-shaped and S-shaped models of population growth of a species.
(b) Explain ‘‘fitness of a species’’ as mentioned by Darwin.
(a) What is an ecological pyramid? Compare the pyramids of energy, biomass and numbers.
(b) Write any two limitations of ecological pyramids.
Question 26: (a) Describe the structure and function of a t-RNA molecule. Why is it referred to as an adapter molecule?
(b) Explain the process of splicing of hn-RNA in a eukaryotic cell.
Write the different components of a lac-operon in E. coli. Explain its expression while in an ‘open’ state.