CBSE Class 12 Biology Sample Paper 2018 Set 05

Section - A

1. A tissue culture experiment has been performed with a plant tissue infected with TMV. Meristematic tissue produces healthy plant. Reason out the possibility of obtaining such result. 1

2. State a method of cellular defence which works in all eukaryotic organisms. 

3. In case of an infertile couple, the male partner can inseminate normally but the mobility of sperms is below 40 percent. Judge, which kind of ART is suited in this situation to form an embryo in the laboratory, without involving a donor? 

4. Calculate the length of the DNA of bacteriophage lambda that has 48502 base pairs. 

5. If two genes are located far apart from each other on a chromosome, how the frequency of recombination will get affected? 

Section - B

6. The alarming population growth is leading to scarcity of basic requirements. Enumerate and justify any two population control measures to overcome this problem. 

7. Both Down’s syndrome and Turner’s syndrome are examples of chromosomal disorders. Cite the differences between the two. 

8. Demand for mushroom as food has led to its culturing on a large scale. Similarly, it is perceived that microbes too would become acceptable as food. Identify a microbe which can be cultured as a food source and give the applicability of its culture in the given context. 

OR

Success rate of artificial insemination in cattle is fairly low. Identify any other mean to improve the successful production of hybrids. State the advantages of this technique. 

9. a) Patients who have undergone myocardial infarction are given clot buster. Mention the clot buster administered and its microbial source.

b) A person recuperating from illness is advised to have curd regularly. Why? 

10. Interpret two effects of loss of biodiversity in a region. 

Section - C

11. Draw and label the enlarged view of microsporangium. State the function of its innermost layer. 

12.

a) State the type of gametes shown in the diagram.

b) Identify the process taking place and the resultant structure.

c) Name an organism that reproduces in this manner. 

13. Diagrammatically represent the experimental set up that proves Oparin - Haldane hypothesis. 

14. A cross is made between different homozygous pea plants for contrasting flower positions.

a) Find out the position of flowers in F₁ generation on the basis of genotypes.

b) Work out the cross upto F₂ generation.

c) Compute the relative fraction of various genotypes in the F₂ generation? 

15. Refer to the figure given below and answer the questions that follow:

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