CBSE Class 12 Biology
CBSE Sample Papers for Class 12 Biology Solved 2016 Set 13
1.Fungus, trichoderma polysperum are proved to be an essential bioactive molecules to the patients under going organ transplantation. Discuss.
2.Mention one example each of the following interaction methods seen among different species of a population.
- Parasitism (ii) Commensalism
3.Smoking of tobacco leads to the deficiency of oxygen in human body. Justify
4.Living organisms fails to survive if the temperature exceeds above 55°C, then how does some microbes are able to compensate in the habitats with temperature exceeding 100°C?
5.Cite the differences between the two types of nutrient cycling found in an ecosystem.
6. Discuss any four ways of basic principles, which lead to fluctuations in population density.
7. State the importance of lactic acid bacteria to humans other than settling milk into curd.
8. Embryo sacs of apomictic species appears normal, but contain diploid cells. Suggest a suitable explanation for the condition.
9. Inheritance pattern of traits in case of human beings cannot be studied by crosses as in case of other organisms. Give reason.
In what way a histone molecule acquires a positive charge? Discuss.
10. In eukaryote, gene expression, i.e. formation of a polypeptide is regulated at four different levels. Explain.
11. Study the graph given below about the number of change of organisms in a water body with respect to a time.
- What does the term A’ and term ‘B’ indicates in the graph?
- Give reason for the occurrence of such a change in the water-body.
12.Draw a well labelled diagram of a male gametophyte of an angiosperm labelling its four major parts.
Describe any three devices by which cross-pollination is encouraged in nature.
13. By taking an example of vertebrate anatomy explain that the evolution of life forms has occurred on earth.
14. In peas, tallness is dominant over dwarfness and red colour of flowers is dominant over the white colour. When a tall plant bearing red flowers was pollinated by a dwarf plant bearing white flowers, different phenotypic groups were obtained in the progeny in numbers mentioned against them.
Mention the genotypes of the two parents involved and the types of four offsprings been obtained in the F2-generation.
15. In what ways human genome project has been proved to be beneficial? Mention any two benefits.
16. Observe the graph given below and correlate the uterine events taking place in the human female body according to the hormonal levels on the respective days.
17. (i) Religious beliefs is proved to be helpful in the conservation of biodiversity.
(ii) State the ecological principle behind the biological control of managing with pest insects.
18. Ritesh was unable to detect DNA bands in gel electrophoresis under UV light after being performing the experiment of DNA isolation many times. Discuss the method and utility of gel electrophoresis in the phenomenon of detection of DNA.
19. “Fisheries plays an important role in Indian economy.” Justify the statement.
20. Molecular diagnostic techniques have been helped a let to detect pathogens from the suspected patients. List the major techniques involved in the detection and their advantage.
21.Highlight the major key differences between the primary and secondary sewage treatment plans.
22. With a help of a flow chart, show the major steps involved in the production of a genetically engineered insulin.
23. Advertisements of sanitary napkins are very frequently shown on TV. Many parents feels that it is not good to be shown publically. They often decided to complain about all this in a local media unit. What do you feel about the issue as a good biology student. Does it really harm the mind set of the children? Share your views both good and bad effects of such advertisements.
24. One of the brilliant student in the classroom of 40 students had start showing a bad performance in his studies when compared to his previous performances. The teacher talked to him in a friendly way and found that he has started taking drugs under the pressure of some of his neighbourhood friends.
- What are the major reasons that mainly led students to take drugs and alcohols?
- List out any three harmful effects of drugs on the performance of students.
- Why it is not easy to leave the drugs it once addicted?
To what extent above mentioned factors would help a drug addict to come over the addiction? Explain in reference to each given below.
- Help from peers
- Education and counselling
- Parental support
- Medical help
- Teacher’s support
25. Explain how does the operator switch is turned on and off in a lac
What conclusion does Darwin made after his journey to a sailship around the world?
26. Describe the role of temperature on different organisms.
List the different types of adaptations found in animals. Explain the each with suitable examples.