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CBSE Pre Board Class 12 2016 : Biology (Assisi Vidyaniketan Public School, Kochi)

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Keven Liam William
Assisi Vidyaniketan Public School
VIth-XIIth Bio Informatic practices

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ASSISI VIDYANIKETAN PUBLIC SCHOOL PERUMPILLY KOCHI PRACTICE EXAM FOR AISSCE 2016 BIOLOGY Class: XII Maximum Marks: 70 Time allowed: 3 hours Pages: 5 Number of General Instructions: (i) There are a total of 26 questions. All questions are compulsory. (ii) Questions 1 to 5 are of one mark each, 6 to 10 are of two marks each, 11 to 22 are of three marks each, 23 is a value based question of 4 marks each, 24 to 26 are of five marks each. (iii) There is no overall choice in the question paper. However an internal choice has been provided in one question of two marks, one question of three marks and all the three questions of five marks. An examinee is to attempt any one of the two given in the question paper with the same question number. (iv) Draw neat and labeled diagrams wherever necessary. SECTION A 1. An anther with malfunctioning tapetum often fails to produce viable male gametophytes. Give any one reason. 2. Name the enzyme and state its property that is responsible for continuous and discontinuous replication of the two strands of a DNA molecule. 3. Write the importance of MOET. 4. Name the type of biodiversity represented by the following: a) 50,000 different strains of rice in India b) Estuaries and alpine meadows in India. 5. Why is the enzyme cellulose needed for isolating genetic material from plant cells and not from the animal cells? SECTION B 6. Geitnogamous flowering plants are genetically autogamous but functionally cross pollination. Justify. 7. When and where do chorionic villi appear in humans? State their function. 8. In a cross between two tall pea plants some of the offsprings produced were dwarf. Show with the help of Punnett square how this is possible. 9. Expand the following and mention one application of each: (a) PCR (b) ELISA OR (a) Mention the difference in the mode of action of exonuclease and endonuclease. (b) How does restriction endonuclease function? 10. Explain why very small animals are rarely found in polar region. SECTION C 11. Draw a diagram of the microscopic structure of a human sperm. Label the following parts in it and write their functions: (a) Acrosome (b) Nucleus (c) Middle piece 12. With the help of any two examples explain the effect of anthropogenic actions on organic evolution 13. Why is human ABO blood group gene considered a good example of multiple alleles? Work out a cross upto first generation only, between a mother with blood group A and the father with blood group B. Explain the pattern of inheritance exhibited. 14. Describe the structure of a RNA polynucleotide chain having four different types of nucleotides. 15. Differentiate between inbreeding and outbreeding in cattle. State one advantage and one disadvantage for each one of them. 16. Why are fruit juices bought from market clearer as compared to those made at home? Name the bioactive molecules produced by Trichoderma polysporum and Monascus purpureus. 17. Why are transgenic animals so called? Explain their role in vaccine safety and biological products with the help of an example each. 18. Explain mutualism with the help of any two examples. How is it different from commensalism? 19. How have human activities caused desertification? Explain. OR How does algal bloom destroy the quality of a fresh water body? Explain. 20. Following the collision of two trains a large number of passengers were killed. A majority of them are beyond recognition. Authorities want to hand over the dead to their relatives. Name a modern scientific method and write the procedure that would help in the identification of kinship. 21. A DNA segment has 2000 nucleotides, out of which 520 are adenine containing nucleotides. How many purine bases this DNA segment possesses? Draw a diagrammatic sketch of a portion of DNA segment to support your answer. 22. A team of students are preparing to participate in the interschool sports meet. During a practice session you find some vials with labels of certain cannabinoids. a. Will you report to the authorities? Why? b. Name a plant from which such chemicals are obtaines. c. Write the effect of these chemicals on human body. SECTION D 23. You have attended a birthday party hosted by one of your classmates. You found some guests at the party sitting in a corner making a lot of noise and consuming something. After a while one of the boys from the group started screaming, behaving abnormally and sweating profusely. On enquiry you found that the group members were taking drugs. (a) Would you inform your parents/school authorities? Yes/No. Give reasons in support of your answer. (b) Prepare a note to be circulated among the schoolmates about the sources and dangers of any two drugs. (c) Write any two ways you will suggest to your school principal so as to promote awareness amongst the youth against the use of these drugs. SECTION E 24. How did Alfred Hershey and Martha Chase conclusively establish that DNA is the genetic material? Explain. OR Describe the mode of transmission, pathogen and symptoms of the following diseases: a) Ascariasis b) Ringworm c) Typhoid 25. Describe the characteristics of wind pollinated flowers. Draw a diagrammatic sectional view of a mature anatropous ovule and label the following parts in it: a) That develops into seed coat. b) That develops into an embryo after fertilization c) That develops into an endosperm in an albuminous seed d) Through which the pollen tube gains entry into the embryo sac. e) That attaches the ovule to the placenta. OR (a) Draw a diagrammatic sectional view of the female reproductive system of human and label the parts (i) Where the secondary oocytes develop (ii) Which helps in collection of ovum after ovulation (iii) Where fertilization occurs (iv) Where implantation of embryo occurs. (b) Explain the role of pituitary and the ovarian hormones in menstrual cycle in human females. 26. What is contraception? Explain the different types of contraceptive methods (any four). OR (a) What is plant breeding? List two steps the classical plant breeding involves. (b) How has the mutation breeding helped in improving crop varieties? Give one example where this technique has helped. (c) How has the breeding programme helped in improving the public nutritional health? State two examples in support of your answer.

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Additional Info : Class 12 CBSE Pre Board 2016 : Biology (Assisi Vidyaniketan Public School, )

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