CBSE Class 12 Biology Sample Paper 2014 Set B

Section-A

1.What are interferons?Also name the kind of immunity provided by it. 

2.Bottled fruit juices bought from the market are clearer as compared to those made at home. Why? 

3. What is founder effect? 

4. Give any two reasons why patent on basmati should not have gone to an American company. 

5.What modificationis done on the Ti plasmid of Agrobacterium tumefaciens to convert it into a cloning vector? 

6. what does ‘competent’refer to in competent cells used in transformation experiments? 

7.Climax stage is achieved quickly in secondary succession as compared to primary succession.

8. What is cultural eutrophication? 

Section-B

9.How does incomplete dominance differ from co-dominance? 

10What are the characteristic features of a true- breeding line? 

11 .While creation and presence of variation is directionless,natural selection is directional as it Is in the context of adaptation.Comment. 

12.From which plant are cannabinoids obtained?Name any two Cannabinoids.Which part of the body is effected by consuming these substance? 

13.Life style diseases are increasing alarmingly in India.We are also dealing with large scale malnutrition in the population.Is there any method by which we can address both these problems? 

14. The restriction enzymes that are used in construction of rDNA molecule are endonucleases Which cut the DNA at ‘specific recognition sequence’. What would be the disadvantage if they Would not cut the DNA at specific –recognition sequence? 

15.What would happen when you grow a recombinant in a bioreactor but forget to add antibiotic to the medium in which the recombinant is growing. 

16. What are the shortcomings of ecological pyramids in the study of ecosystem? 

17. Primary productivity varies from ecosystem to ecosystem.Explain. 

OR

Explain with the help of two examples,how the pyramid of numbers and the pyramid of biomass can look inverted.

18. How does culturing of spirulina solve the food problems of the growing human population?  

Please refer to attached file for CBSE Class 12 Biology Sample Paper 2014 Set B