NIOS Class 12 Biology Chapter 30 Biotechnology

NIOS Class 12 Biology Chapter 30 Biotechnology Solutions to each chapter is provided in the list so that you can easily browse throughout different chapters NIOS Class 12 Biology Chapter 30 Biotechnology Notes and select need one. NIOS Class 12 Biology Chapter 30 Biotechnology Question Answers Download PDF. NIOS Study Material of Class 12 Biology Notes Paper 314.

NIOS Class 12 Biology Chapter 30 Biotechnology

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Also, you can read the NIOS book online in these sections Solutions by Expert Teachers as per National Institute of Open Schooling (NIOS) Book guidelines. These solutions are part of NIOS All Subject Solutions. Here we have given NIOS Class 12 Biology Chapter 30 Biotechnology Solutions, NIOS Senior Secondary Course Biology Solutions for All Chapter, You can practice these here.


Chapter: 30




1. Name three different kinds of microorganisms used in the manufacture of industrial products.

Ans: (i) Fungi.

(ii) yeast. and 

(iiI) bacteria are three kinds of microbes used.

2. Name three products obtained in industries by using microorganisms. 

Ans: (i) Alcohol.

(ii) antibiotics.

(iii) vaccines.

3. Name two alcohols produced through fermentation by yeast.

Ans: (i) Ethanol. and 

(ii) glycerol are produced by fermentation of yeast.

4. Name the two methods of inoculation of yeast in the medium.

Ans: (i) Support growth system.

(ii) sus-pended growth system.

5. Match the items given in column A with those given in column B.

Column AColumn B
1. Bioreactor(a) Butanol
2. Steaming under pressure(b) Fermentation tank
3. Alcohol(c) Autoclave


Column AColumn B
1. Bioreactor(b) Fermentation tank
2. Steaming under pressure(c) Autoclave
3. Alcohol(a) Butanol


1. Name the bacterium responsible for curdling of milk.

Ans: Lactobacillus (LAB).

2. Who discovered antibiotics?

Ans: Alexander Flemming discovered antibiotics.

3. What do you mean by second generation vaccines?

Ans: The vaccines are produced by recom-binant DNA technology. They are called second generation vaccines.

4. Which was the first vitamin to be produced by fermentation?

Ans: Vitamin C (ascorbic acid).

5. Which bacteria cause the production of biogas?

Ans. The methanogenic bacteria produce biogas.


1. Define genetic engineering.

Ans: The construction as well as the use of novel DNA molecules obtained by recombinant DNA technology.

2. What is a clone?

Ans: The clone is “a group of genetically identical cells obtained by asexual division of a cell”.

3. What do you mean by the term recombinant DNA?

Ans: If a fragment of the foreign DNA is inserted in the DNA of a phage/plasmid, DNA of the later is known as r-DNA/recombinant DNA.

4. Where are plasmids found? 

Ans: Plasmids are found in bacteria.

5. Why are restriction enzymes called “molecular scissors”?

Ans: Since they can cut specific sudden of DNA.

6. Name the enzyme which joins DNA fragments.

Ans: Ligase joins DNA fragments.

7. What is a clonal vector?

Ans: A phage or plasmid that may carry foreign DNA; divide along with bacterium whose part it is.

8. What do you mean by transgenic organisms?

Ans: These are genetically engineered organisms called GMOs carrying foreign genes.


1. Name any two proteins and two enzymes obtained by recombinant DNA technology.

Ans: (i) Insulin, Growth Hormone. and 

(ii) Proteases, amylase.

2. How is recombinant DNA technology useful for pharmaceutical companies?

Ans: The antibiotics, vaccines, proteins are manufactured by r-DNA technology having clinical value.

3. Name any two diseases for which bioengineered vaccines have already been developed.

Ans: (a) Hepatitis B.

(b) Rabies.


1. Define a term transgenic.

Ans: Transgenic is an “organism containing foreign DNA in its genome.”

2. Name the gall producing bacterium and the plasmid which can be conveniently used to produce transgenics.

Ans: (i) Agrobacterium tumefaciens. and 

(ii) Ti plasmid.

3. What is bioremediation?

Ans: The bioremediation is defined as “the removal of pollutants in environment by using genetically engineered bacteria”.


1. What causes the alteration of normal functioning of a gene?

Ans: Mutation.

2. Name two single gene disorders in human beings. 

Ans: (i) Haemophilia.

(ii) Sickle cell anaemia.

3. State which cells have a low count in Severe Combined Immuno Deficiency (SCID).

Ans: B-cells and T-cells.

4. Define gene therapy.

Ans: Gene therapy is defined as “the replacement and alteration of defective gene”.


1. State the two approaches to human gene therapy.

Ans: (i) Somatic. and 

(ii) Germ line cells.

2. Name the three categories of somatic cell gene therapy.

Ans: (i) In-vivo gene therapy.

(ii) ex-vivo gene therapy. and 

(iii) antisense gene therapy.

3. Name any two genetic diseases that can be treated by somatic gene therapy.

Ans: (a) Thalassemia.

(ii) Some types of cancer.

4. What is the direct delivery of the corrected gene into the tissue of the patient by the use of adenovirus called?

Ans: It is known as the “In-vivo gene therapy”.


1. Define biotechnology.

Ans: The biotechnology is defined as “the application of scientific knowledge by industries which produces biological products such as vaccines, vitamins, food supplements, enzymes, drugs etc”.

2. How are alcoholic beverages produced by fermentation? Mention the steps in the process.

Ans: Fermentation is “a process by which sugar is altered into alcohol and carbon dioxide by bacteria and yeast.” They ferment sugar into alcoholic beverages. Further more fermentation by Saccharomyces (yeast) produces beer and butter milk also.

The extract of yeast, after beverages have been removed is used as animal feed.

3. How can you make cheese and curd on a large scale?

Ans: Making cheese and curd on large scale: For it rennet tablets are used. The milk on large scale is curdled by renin or bacteria and whey is separated. LAB changes milk into lactic acid that lowers pH causing souring. The starter culture of Streptococcus cremosis is added to milk to obtain cheese and curd.

4. What are antibiotics? Name five antibiotics and their sources.

Ans: Antibiotics: It is a substance (small molecules) that “is produced by microbes like fungi/bacteria that inhibits the growth of another microbes”.

Five Antibiotics and Their Sources:

1. PenicillinPenicillium chrysogenum
2. TetracyclineStreptomyces species
3. CyclohexamideStreptomyces griseus
4. ChlorotetracyclineS. auriefaciens
5. CephalosporinCephalosporium

5. How are different generations of vaccines produced?

Ans: Preparation of different Gene-rations of Vaccines. The vaccines are prepared

(a) from attenuated or weakened germs are called first generation vaccines.

(b) By recombinant DNA technology the second generation vaccines are produced.

(c) The vaccines synthesised by chemicals are called third generation vaccines.

6. Describe the steps in the production of biogas and mention the precautions to be taken.

Ans: Production of Biogas: The biogas is produced by the action of methanogenic bacteria on the waste matter like cattle dung and human faeces etc. It is organic matter that is biodegraded by bacteria and fermented anaerobically by methanogenic bacteria. Cow dung is kept in digester tank. It acts as a fermenter. After chemical reactions by bacteria, CH, (methane) is produced. The slurry left is used as manure.

Precautions taken: (i) The pH in fermentor must be 6.8 to 7.6 (near to neutral).

(ii) anaerobic environment be maintained.

(iii) there should be no tree O₂.

(iv) bacteria used for fermentation should be CH4 generating.

7. Enumerate in a sequence the steps in recombinant DNA technology.

Ans: Steps in Recombinant DNA Technology:

(i) The restriction enzyme cleaves the desired DNA or gene from the cells in a cell culture.

(ii) Cuts plasmids.

(iii) The cut segment of DNA (desired gene) is united to plasmid by ligase enzyme.

(iv) The plasmid is inserted into its host bacterium.

(v) The bacterium divides to form a clone.

Fig. 30.2. The main steps in formation of multiple copies of recombinant DNA for DNA library

8. Describe the uses of genetic engineering.

Ans: Uses of Genetic Engineering: The genetic engineering is popularly known as manipulation of gene or Recombinant DNA Technology. It is also referred to as gene splicing.

It may be used to obtain commercially pro- teins like growth hormone, insulin, interferons, clotting factors, erythropoitin, monoclonal antibodies, enzymes, antibodies and vaccines for rabies and hepatitis.

9. How can a transgenic animal be obtained?

Ans: The transgenic animals are produced by microinjection of foreign DNA into the fertilised eggs. It is done by using retrovirus for introducing foreign DNA into early embryonic stages e.g., transgenic cow, sheep, pig, rat, mouse, fishes etc.

Main steps are:

(i) Removal of nucleus from the fertilised egg.

(ii) Microinjection of a nucleus from the donor cell.

(iii) Implantation of transgenic embryo in the uterus of a surrogate mother.

(iv) Gestation and birth of the Animal.

10. Write a note on bioremediation.

Ans: Bioremediation: The genetically engineered bacteria may clean up the pollutants from the environment. It is known as the bioreme-diation. It is the use of living microbes or GM microbes to degrade the environmental pollutants or to remove pollutants from the environment. The hazardous substances accumulated in cells are removed. The dyes, HCs, industrial wastes, heavy metals, genobiotics etc. are removed by microbes.

11. Define the term gene therapy. Under what condition does it become necessary to opt for such a therapy?

Ans: Gene Therapy: It is defined “as the insertion of genes into individual cells/tissues to cure diseases, mostly hereditary diseases”. The defective genes are replaced by functional genes. The vectors/viruses are used for it. Gene therapy involves the delivery of a normal gene into embryo/individual to take over the act of a non-functional gene. The first gene therapy was given to a four years old girl child in 1990 with ADA (adenosine deaminase) deficiency. The functional ADA is injected into the patient for treatment.

Selected Human Genetic Diseases for Possible Single Gene Therapy or Correction of Single Gene Defects:

SL.NoName of disease(s)Target TissueIncidence of Diseases
1Cystis fibrosisLiver1: 500
2D. Muscular DystrophyMuscle/Brain1 : 300 (males).
3ThalassemiaBone Marrow1: 600
4Haemophilia-BFibroblasts1 : 30,000 (males)

12. What is meant by human somatic gene therapy? How does it differ from the germ line gene therapy? Which of the two have been successful so far and why?

Ans: Somatic Gene Therapy: The treatment that is applied to cells excluding germ line cells is known as the somatic gene therapy.

Genetic defects are corrected in somatic cells of body and the genetic defect of a specific tissue/ organ is corrected.

Germ line Gene Therapy: Functional genes are introduced into germ cells of patients for correction e.g., Embryo therapy.

Germ line gene therapy is most successful so far because the germ cells inherit the characteristics It is carried out in labs and is farm animals. It is not applied in human due to ethical problems.

13. Discuss in brief the different types of somatic gene therapy.

Ans: Different types of somatic gene therapy: Three main therapeutic approaches to gene therapy are:

(i) ex-vivo gene therapy.

(ii) in-vivo gene therapy.

(iii) anti sense gene therapy.

(i) Ex-vivo gene therapy: This includes “the addition of corrected genes through retroviral cloning vectors”.

(ii) In-vivo gene therapy: It includes “direct delivery (carried by vectors) of corrected genes into tissues by using of adenovirus”.

(iii) Anti sense therapy: It is designed “to prevent or lower expression of gene in order to have less accumulation of a gene product”.

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