NCERT Solutions for Class 12 Biology Chapter 11 Biotechnology Principles and Processes

 

NCERT solutions for class 12 biology chapter 11 biotechnology principles and processes: Biotechnology is a field which deals with the combination of biology and technology. The techniques of using live organisms or enzymes taken from organisms to produce products and processes which are useful to humans. For example: making curd, bread or wine, which are all microbe-mediated processes. It could also be thought of as a form of biotechnology. CBSE NCERT solutions for class 12 biology chapter 11 biotechnology principles and processes will provide you with all the answers of questions mentioned in this chapter. Likewise, so many other processes/techniques are also included under the process of biotechnology. For example, in vitro fertilisation leading to a ‘test-tube’ baby, synthesizing a gene and using it, developing a DNA vaccine or correcting a defective gene, are all part of biotechnology. Solutions of NCERT class 12 biology chapter 11 biotechnology principles and processes will make learning easier for you. In this chapter, you will also study the different processes of biotechnology. If you are looking for the answers of any other class from 6-12 then NCERT solutions are there for you.

Here are the important topics of NCERT solutions for class 12 biology chapter 11 biotechnology principles and processes are given below:

11.1 Principles of Biotechnology

11.2 Tools of Recombinant DNA Technology

    11.2.1 Restriction Enzymes

    11.2.2 Cloning Vectors

    11.2.3 Competent Host (For Transformation with Recombinant DNA)

11.3 Processes of Recombinant DNA Technology

    11.3.1 Isolation of the Genetic Material (DNA)

    11.3.2 Cutting of DNA at Specific Locations

    11.3.3 Amplification of Gene of Interest using PCR

    11.3.4 Insertion of Recombinant DNA into the Host Cell/Organism

    11.3.5 Obtaining the Foreign Gene Product

    11.3.6 Downstream Processing

NCERT Solutions for Class 12 Biology Chapter 11 Biotechnology Principles and Processes - Solved Exercise Questions

Biotechnology: Principles and Processes Excercise:

 

Q1. Can you list 10 recombinant proteins which are used in medical practice? Find out where they are used as therapeutics (use the internet).

Answer:

Recombinant proteins are proteins produced as a result of recombinant DNA technology. In this technology, there is the transfer of some specific gene from one organism to another by using molecular tools such as biological vectors, restriction enzymes etc. Some of the proteins produced through RDT and are being used for therapeutic uses are as follows:

S.No 

Name of the recombinant protein

Therapeutic use of the recombinant protein

1.

DNAase I

To treat cystic fibrosis

2.

Antithrombin III

To prevent the formation of the blood clot

3.

Insulin 

To treat type I diabetes mellitus

4.

Interferon \alpha

Used for chronic hepatitis C

5.

Interferon AZA

Used for herpes and virus enteritis

6.

Coagulation factor VIII

To treat haemophilia A

7.

Coagulation factor IX

To treat haemophilia B

8.

Interferon B

To treat multiple sclerosis

9.

Human growth hormone recombinant 

To promote growth in humans

10.

Tissue plasminogen activator 

To treat the myocardial infection

 

Q2. Make a chart (with diagrammatic representation) showing a restriction enzyme, the substrate DNA on which it acts, the site at which it cuts DNA and the product it produce

Answer:

The following chart shows the action of the restriction enzyme EcoRI, the substrate DNA on which it acts and the site where it cuts

Activity of restriction enzyme EcoRI

Q4. What would be the molar concentration of human DNA in a human cell? Consult your teacher.

Answer:

The molar concentration of DNA  in a human cell will be total no. of chromosomes multiplied by 6.023\times 10^{23}

Hence, the molar concentration DNA in each diploid cell in humans is 46\times 6.023\times 10^{23} = 2.77\times 10^{23} moles

Q5. Do eukaryotic cells have restriction endonucleases? Justify your answer.

Answer:

No, eukaryotic cells do not possess restriction enzymes. All the restriction endonucleases have been developed and isolated from different strains of bacteria. The bacteria possess these restriction endonucleases as a defence mechanism to restrict the growth of viruses. Their own DNA remain safe from these enzymes because it is methylated. The eukaryotic cell has RNA interference as a defence mechanism against foreign DNA. Thus, eukaryotic cells do not have restriction endonucleases.

Q6. Besides better aeration and mixing properties, what other advantages do stirred tank bioreactors have over shake flasks?

Answer:

The advantages of stirred tank bioreactors over shake flasks are as follows:

1. Stirred tank bioreactors are utilised for large-scale production of biotechnological products, unlike the shake flask method which is used for small-scale production of products. 

2. In stirred tank bioreactors, a small sample can be taken out for testing.

3. Stirred tank bioreactors have foam breakers to control the foam.

4. Stirred tank bioreactors have temperature and pH control systems.

Q7. Collect 5 examples of palindromic DNA sequences by consulting your teacher. Better try to create a palindromic sequence by following base-pair rule

Answer:

Palindromic sequences in the DNA molecule refer to groups of bases forming the same sequence when read either backwardly or forwardly. The recognition sites of restriction endonucleases are palindromic sequences. Five examples of palindromic DN sequences are given below

1. ACTAGT/TGATCA

2. AAGCTT/TTCGAA

3. GGATCC/CCTAGG

4. AGGCCT/TCCGGA

5. ACGCGT/TGCGCA

Q8. Can you recall meiosis and indicate at what stage a recombinant DNA is made?

Answer:

In meiosis, during the pachytene stage of Prophase I, crossing-over takes place and recombinant DNA is formed by combining portions of male and female DNA.

Q9. Can you think and answer how a reporter enzyme can be used to monitor transformation of host cells by foreign DNA in addition to a selectable marker?

Answer:

In recombinant DNA technology selection of transformed and non transformed cells can be done using reporter genes that encode for reporter enzymes. During the RDT experiment, the foreign gene is joined with a reporter gene. The reporter gene should be such that it produces a visible expression. For example, Lac Z gene which codes for enzyme beta-galactosidase is used as a reporter gene. The activity of this gene is not found in transformed cells as the product formed by its catalysation is not formed in transformed cells and bacterial colonies appear white. In non-transformed cells, this gene shows its activity and the catalysed product is formed, as a result of this, bacterial colonies appear blue. Thus, reporter enzyme can be used to monitor the transformation of host cells by foreign DNA in addition to a selectable marker.

Q10. Describe briefly the following: (a) Origin of replication

Answer:

Origin of replication- This refers to the DNA sequence, from where replication of DNA starts. By linking a DNA sequence with the origin of replication, it can be allowed to replicate in the host cells. Origin of replication also controls the copy number of linked DNA sequence. 

(b) Bioreactor

Answer:

Bioreactors- These are large vessels (100-1000 litres)  that are used for large-scale production of biotechnological products such as proteins, enzymes etc. from raw materials. In a bioreactor, optimum conditions such as temperature, pH, vitamins, oxygen, salts etc. are maintained. Stirred bioreactors are the most commonly used bioreactors. Stirred bioreactors can be simple stirred tank bioreactors or sparged tank bioreactors. 

NCERT solutions for class 12 biology chapter 11 biotechnology principles and processes

(c) Downstream processing

Answer:

Downstream processing- The process of separation and purification of biotechnological products is called downstream processing. The processes in downstream processing vary depending on the quality of the product. Before the release of the product, it undergoes clinical trials and quality control testings. 

Q11. Explain briefly : (a) PCR

Answer:

Polymerase Chain Reaction (PCR)- The molecular technique to amplify a gene and obtain its several copies is referred to as PCR. The process of PCR has certain requirements i.e. a thermostable enzyme called Taq polymerase ( obtained from Thermus aquaticus), primers ( short stretches of DNA ), dNTPs, a template strand etc. The process of PCR takes place in three steps. 

1. Denaturation- The double-stranded DNA helix is opened up by breaking their H-bonds at high temperature. 

2. Annealing- The primers are allowed to hybridise to complementary regions of DNA. This step takes place at 45-55 C temperature.

3. Extension- The primers are extended with the help of Taq polymerase enzyme and the cycle is repeated several times to obtain the desired number of copies. 

(b) Restriction enzymes and DNA

Answer:

Restriction enzymes and DNA- Restriction enzymes are those enzymes which cut DNA at particular places. Restriction enzyme first scans the DNA template and look for its recognition site. Once it finds the recognition site, it binds at that region of DNA and cut each of the two strands in their sugar-phosphate backbone. The sites at which restriction enzymes cut DNA are called as recognition sites of DNA. These are palindromic sequences i.e. they read similar from the backward and forward direction. 

(c) Chitinase

Answer:

Chitinase- The enzyme that catalyses the breakdown of chitin polysaccharide which is usually found in the cell wall of fungi. Chitinase is mainly used during DNA isolation from fungi. 

Q12. Discuss with your teacher and find out how to distinguish between

(a) Plasmid DNA and Chromosomal DNA

Answer:

The differences between plasmid DNA and chromosomal DNA are as follows:

Plasmid DNA           

Chromosomal DNA   

Circular, extra-chromosomal DNA which is capable of self-replication and is found in bacteria is called plasmid DNA. 

The entire DNA (excluding extrachromosomal DNA) present in the cell constitutes chromosomal DNA 

It is found only in bacteria

IT is found in both bacteria and other eukaryotic cells. 

(b) RNA and DNA

Answer:

The differences between RNA and DNA are as follows: 

RNA 

DNA 

RNA contains ribose sugar        

DNA contains deoxyribose sugar 

In RNA, adenine and uracil are found as pyrimidines 

In DNA, adenine and uracil are found as pyrimidines

It has catalytic properties and is less stable than DNA 

DNA is non-catalytic and is stable than RNA

(c) Exonuclease and Endonuclease

Answer:

The differences between exonuclease and endonuclease are as follows: 

Exonuclease

Endonuclease

These are nuclease (enzymes) that cut DNA from its ends.

These are nucleases that cut DNA from internal sites on DNA 

 

In NCERT solutions for class 12 biology chapter 11 biotechnology principles and processes and marketing of products and processes using live organisms, cells or enzymes. Modern biotechnology using genetically modified organisms was made possible only when man learned to alter the chemistry of DNA and construct recombinant DNA. This process of combination is called recombinant DNA technology or genetic engineering. This process includes the use of these things: restriction endonucleases, DNA ligase, appropriate plasmid or viral vectors to isolate the foreign DNA into the host organisms. And for large scale production bioreactors are being used.

NCERT Solutions class 12 Biology

Chapter 1

NCERT solutions for class 12 biology chapter 1 Reproduction in organisms

Chapter 2

Solutions of NCERT class 12 biology chapter 2 Sexual Reproduction in Flowering Plants

Chapter 3

CBSE NCERT solutions for class 12 biology chapter 3 Human Reproduction

Chapter 4

NCERT solutions for class 12 biology chapter 4 Reproductive Health

Chapter 5

Solutions of NCERT class 12 biology chapter 5 Principles of Inheritance and Variation

Chapter 6

CBSE NCERT solutions for class 12 biology chapter 6 Molecular basis of inheritance

Chapter 7

NCERT solutions for class 12 biology chapter 7 Evolution

Chapter 8

Solutions of NCERT class 12 biology chapter 8 Human health and disease

Chapter 9 

CBSE NCERT solutions for class 12 biology chapter 9 Strategies for Enhancement in Food Production

Chapter 10

NCERT solutions for class 12 biology chapter 10 Microbes in Human Welfare

Chapter 11

Solutions of NCERT class 12 biology chapter 11 Biotechnology Principles and Processes

Chapter 12

CBSE NCERT solutions for class 12 biology chapter 12 Biotechnology and its Applications

Chapter 13

NCERT solutions for class 12 biology chapter 13 Organisms and Populations

Chapter 14

Solutions of NCERT class 12 biology chapter 14 Ecosystem

Chapter 15

CBSE NCERT solutions for class 12 biology chapter 15 Biodiversity and Conservation

Chapter 16

NCERT solutions for class 12 biology chapter 16 Environmental Issues

NCERT Solutions for Class 12 Subject wise

Solutions for NCERT Class 12 Maths

CBSE NCERT solutions for Class 12 Chemistry

NCERT solutions for  Class 12 Biology

Solutions for NCERT Class 12 Physics

After going through NCERT solutions for class 12 biology chapter 11 biotechnology principles and processes you should be able to write better now in your board exams. If you have any doubt, then, NCERT solutions for class 12 biology chapter 11 biotechnology principles and processes will help you.

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  • NCERT solutions for class 12 biology chapter 11 biotechnology principles and processes will help you to clear your base as NCERT is the base of your learning.
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