CBSE Class 12 Biology Biotechnology Principles And Processes Notes Set B

Download CBSE Class 12 Biology Biotechnology Principles And Processes Notes Set B in PDF format. All Revision notes for Class 12 Biology have been designed as per the latest syllabus and updated chapters given in your textbook for Biology in Standard 12. Our teachers have designed these concept notes for the benefit of Grade 12 students. You should use these chapter wise notes for revision on daily basis. These study notes can also be used for learning each chapter and its important and difficult topics or revision just before your exams to help you get better scores in upcoming examinations, You can also use Printable notes for Class 12 Biology for faster revision of difficult topics and get higher rank. After reading these notes also refer to MCQ questions for Class 12 Biology given our website

Biotechnology Principles And Processes Class 12 Biology Revision Notes

Class 12 Biology students should refer to the following concepts and notes for Biotechnology Principles And Processes in standard 12. These exam notes for Grade 12 Biology will be very useful for upcoming class tests and examinations and help you to score good marks

Biotechnology Principles And Processes Notes Class 12 Biology


Biotechnology is a broad area of science involving multiple disciplines designed to use living organisms or their products to perform valuable industrial or manufacturing processes or applications pertaining to human benefit.

Recombinant DNA technology:

An organism's genome contains virtually all the information necessary for its growth and development .rDNA technology creates a recombined DNA with genome of two different cells or organisms.

Steps in producing recombinant DNA

1. The required gene is cut from a DNA molecule using a restriction enzyme. 

2. A bacterial plasmid is isolated and cut with the same restriction enzyme. This ensures cut ends are complementary (same base sequence) to the ends of the required gene.

3. The required gene is joined to the plasmid using the enzyme DNA ligase in a process called ligation. 

4. The resulting recombinant plasmid is returned to the bacterial cell. 

5. The bacteria reproduce and the required gene is cloned..



To isolate genomic DNA

1. Remove tissue from organism

2. Homogenize in lysis buffer (denatures proteins)

3. Mix with phenol/chloroform - removes proteins

4. Keep aqueous phase (contains DNA)

5. Add alcohol (ethanol or isopropanol) to precipitate DNA from solution

6. Collect DNA pellet by centrifugation

7. Dry DNA pellet and resuspend in buffer

8. Store at 4°C 

Each cell (with a few exceptions) carries a copy of the DNA sequences which make up the organism's genome.

Recombinant DNA technology


-Isolation of DNA

- Digestion using Restriction enzymes

- urification of the TARGET fragment

- Ligation with cloning vector.

- Transformation of host cell and selection of transformed cells

- Culturing for the desired product.

Important Questions for NCERT Class 12 Biology Biotechnology: Principles and Processes


Ques. Which one of the following palindromic base sequences in DNA can be easily cut at about the middle by some particular restriction enzyme?
(a) 5'------CGTTCG------3' 
(b) 5'------GATATG------3' 
(c) 5'------GAATTC------3' 
(d) 5'------CACGTA------3' 

Answer: C


Ques. Which one of the following is used as vector for cloning genes into higher organisms?
(a) Baculovirus
(b) Salmonella typhimurium
(c) Rhizopus nigricans (d) Retrovirus 

Answer: D


Ques. DNA or RNA segment tagged with a radioactive molecule is called
(a) vector (b) probe
(c) clone (d) plasmid. 

Answer: B


Ques. Restriction endonucleases are enzymes which
(a) make cuts at specific positions within the DNA molecule
(b) recognize a specific nucleotide sequence for binding of DNA ligase
(c) restrict the action of the enzyme DNA polymerase
(d) remove nucleotides from the ends of the DNA molecule. 

Answer: A


Ques. In genetic engineering, a DNA segment (gene) of interest, is transferred to the host cell through a vector. Consider the following four agents (i-iv) in this regard and select the correct option about which one or more of these can be used as a vector/vectors.
(i) Bacterium (ii) Plasmid
(iii) Plasmodium (iv) Bacteriophage
(a) (i), (ii) and (iv) (b) (i) only
(c) (i) and (iii) (d) (ii) and (iv)

Answer: D


Ques. Polyethylene glycol method is used for
(a) biodiesel production
(b) seedless fruit production
(c) energy production from sewage
(d) gene transfer without a vector. 

Answer: D


Ques. Which one of the following is commonly used in transfer of foreign DNA into crop plants?
(a) Meloidogyne incognita
(b) Agrobacterium tumefaciens
(c) Penicillium expansum
(d) Trichoderma harzianum 

Answer: B


Ques. Gel electrophoresis is used for
(a) construction of recombinant DNA by joining with cloning vectors
(b) isolation of DNA molecules
(c) cutting of DNA into fragments
(d) separation of DNA fragments according to their size. 

Answer: D


Ques. The linking of antibiotic resistance gene with the plasmid vector became possible with
(a) DNA polymerase (b) exonucleases
(c) DNA ligase (d) endonucleases. 

Answer: C


Ques. Restriction endonuclease
(a) synthesizes DNA
(b) cuts the DNA molecule randomly
(c) cuts the DNA molecule at specific sites
(d) restricts the synthesis of DNA inside the nucleus.

Answer: C


Ques. Two microbes found to be very useful in genetic engineering are
(a) crown gall bacterium and Caenorhabditis elegans
(b) Escherichia coli and Agrobacterium tumefaciens
(c) Vibrio cholerae and a tailed bacteriophage
(d) Diplococcus sp. and Pseudomonas sp.

Answer: B


Ques. Restriction endonucleases
(a) are present in mammalian cells for degradation of DNA when the cell dies
(b) are used in genetic engineering for ligating two DNA molecules
(c) are used for in vitro DNA synthesis
(d) are synthesized by bacteria as part of their defense mechanism. 

Answer: D


Ques. The Ti plasmid, is often used for making transgenic plants. The plasmid is found in
(a) Azotobacter
(b) Rhizobium of the roots of leguminous plants
(c) Agrobacterium
(d) Yeast as a 2 mm plasmid. 

Answer: C


Ques. The most thoroughly studied of the known bacteriaplant interactions is the
(a) cyanobacterial symbiosis with some aquatic ferns
(b) gall formation on certain angiosperms by Agrobacterium
(c) nodulation of Sesbania stems by nitrogen fixing bacteria
(d) plant growth stimulation by phosphatesolubilising bacteria. 

Answer: B


Ques. Which one of the following bacteria has found extensive use in genetic engineering work in plants ?
(a) Clostridium septicum
(b) Xanthomonas citri
(c) Bacillus coagulens
(d) Agrobacterium tumefaciens 

Answer: D


Ques. Which of the following enzymes are used to join bits of DNA?
(a) Ligase (b) Primase
(c) DNA polymerase (d) Endonuclease

Answer: A


Ques. A mutant strain of T4 - Bacteriophage, R-II, fails to lyse the E. coli but when two strains R-IIX and R-IIY are mixed then they lyse the E. coli. What may be the possible reason?
(a) Bacteriophage transforms in wild.
(b) It is not mutated.
(c) Both strains have similar cistrons.
(d) Both strains have different cistrons.

Answer: D


Ques. Which of the following cut the DNA from specific places?
(a) E.coli restriction endonuclease I
(b) Ligase
(c) Exonuclease
(d) Alkaline phosphate

Answer: A


Ques. Maximum number of bases in plasmids discovered so far
(a) 50 kilo base (b) 500 kilo base
(c) 5000 kilo base (d) 5 kilo base. 

Answer: B


Ques. Plasmid has been used as vector because
(a) it is circular DNA which have capacity to join to eukaryotic DNA
(b) it can move between prokaryotic and eukaryotic cells
(c) both ends show replication
(d) it has antibiotic resistance gene. 

Answer: A


Ques. The process of replication in plasmid DNA, other than initiation, is controlled by
(a) mitochondrial gene
(b) plasmid gene
(c) bacterial gene
(d) none of these. 

Answer: C

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