Biotechnology: Principles & Processes: Class 12 Previous Year Questions

Biotechnology: Principles & Processes questions asked in CBSE board exams

Repeated questions first. Open the free app to see each question as it appeared in the paper, with its marking scheme.

1. Gene manipulation is a fast emerging science. It started with the development of recombinant DNA molecules. This technology which mostly involves cutting and pasting of desired DNA fragments is based on two most important discoveries in bacteria – presence of …
   Board 20264 marksshort answer
2. _________ Page 7 of 24 { } 9. Which of the following is used to visualize DNA bands under UV light after gel electrophoresis ? 1 (A) Acetocarmine (B) Safranine (C) Ethidium Bromide (D) Potassium Iodide _________ Page 8 of 24 { } 10.     …
   Board 20261 markMCQ
3. _________ Page 9 of 24 { } 11. Genetically modified tobacco plants were produced using Agrobacterium vectors. Which property of Agrobacterium helps in carrying nematode specific genes into the host plant ? 1 (A) Infectious for monocot plant ; has Ti plasmid (B…
   Board 20261 markMCQ
4. (a) Write the palindromic nucleotide sequence for following sequence of DNA segment : 5'- GAATTC- 3' (b) Name the restriction endonuclease that recognizes this sequence. How are sticky ends produced ? Mention their role.
   Board 20253 marksshort answer
5. Student to attempt either option-(A) or (B) : (A) A patient with ADA deficiency requires periodic infusion of genetically engineered lymphocytes. Explain why such periodic infusion is required and also suggest a permanent cure for such ADA deficiency. OR (B) D…
   Board 20252 marksshort answer
6. Assertion (A) : A bioreactor provides the optimal conditions for achieving the desired product by providing optimum growth conditions. Reason (R) : The most commonly used bioreactors are of stirring type.
   Board 20251 markAssertion-Reason
7. Select the correct statement from 11. thefollowingbiotechnological procedures : (A) The polymerase enzyme joins the gene of interest and the vector DNA. (B) Gel electrophoresis is used for amplification of a DNA segment. (C) PCR is used for isolation and separ…
   Board 20251 markMCQ
8. (a) d to detect recombinant DNA. Explain the method. 2 OR (b) Explain how recombinant DNA technology is used to detect a disease even before any clinical symptom appears.
   Board 20232 marksshort answer
9. JJJJ Page 3 1. Which one of the following processes results in the production of recombinants in future generations ? (i) Mutation (ii) Independent assortment during meiosis I (iii) Independent assortment during meiosis II (iv) Crossing over of bivalents (a) (…
   Board 20231 markMCQ
10. (i) State the role of a selectable marker in r-DNA technology. (ii) Name one such selectable marker which is considered to be useful for E.coli. (ii) Give one reason why is it considered to be a useful marker. OR What are plasmids ? How are they different from…
    Board 20221 markvery short
11. Name two naturally occurring sources, one that transfers pathogenic genes into a plant cells and the other into an animal cell respectively, for their benefit. Write how have these naturally occurring sources been used for the benefit of human race by the biot…
    Board 20221 markvery short
12. AmYw{ZH$ àm¡Úmo{JH$s H$s AmZwd§{eH$ B§Or{Z`[a¨J VH$ZrH$m| Ho$ {dH$mg go A~ h_ S>r.EZ.E. H$mo gabVm go n¥WH$ H$a n[aewÕ H$a gH$Vo h¢ & µOm| Ûmam H$mQ>o JE Um| H$m Zm_ {bI H$a CZH$s ì`m»`m H$s{OE & 3 (b) (i) When prickly pear cactus was introduced into Australia…
    Board 20221 markvery short
13. Assertion (A): DNA ligase is not used in PCR. Reason (R): Discontinuous fragments are not formed in the amplification of DNA by PCR.
    CBSE practice 2023-241 markAssertion-Reason
14. Assertion: Plasmids and bacteriophages are used as cloning vectors in rDNA technology. Reason: They have low copy number of their genome within the bacterial cell.
    CBSE practice 2023-241 markAssertion-Reason
15. For a fruit plant naturally growing in moderate water availability, GM techniques can help in incorporating drought escape characteristics. This will reduce their life cycle duration and can have adverse impacts. State ONE such possible impact on the commercia…
    CBSE practice 2021-225 markslong answer
16. The sequences amp marker and tet marker are the selectable markers in the plasmid and help in transformation and can help in differentiating the non-recombinants from the transformants. This is done using 'chromogenic substrates'. (a) What is the chemical basi…
    CBSE practice 2021-225 markslong answer
17. Mention any TWO characteristics that are important for a cloning vector. [1 marks] ***End of Paper***
    CBSE practice 2021-225 markslong answer
18. Papaya is a widely cultivated crop in several regions. However, its production was limited by papaya ringspot disease which is caused by the Papaya ringspot virus (PRSV). Papaya plants infected by PRSV show symptoms of yellowing, 5 discolouration of leaves and…
    CBSE practice 2022-235 markscase-based
19. Shown below is a cloning vector 'Z' that Kamla wants to use to create a recombinant vector with her gene of interest. The vector consists of sites for three restriction enzymes - ScaI, HindIII and EcoRI. Restriction sites for the same enzymes are also present …
    CBSE practice 2023-244 marksshort answer
20. In recombinant DNA technology, the endonuclease cuts the DNA into fragments. (a) Where does a restriction endonuclease cut the DNA strand? (b) How is the restriction endonuclease able to cut the DNA strand as mentioned in (a)? (c) DNA fragments formed by the a…
    CBSE practice 2021-223 marksshort answer

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