Biotechnology and Its ApplicationsNEET Botany · Class 12 · NCERT Chapter 8

Solution

The first human hormone produced by recombinant DNA technology is insulin. NCERT XII chapter Biotechnology and its Applications details the production of human insulin by genetic engineering in bacteria, making option (a) correct.

Solution

Southern hybridization involves electrophoresis to separate DNA fragments, blotting to transfer them to a membrane, and autoradiography to detect the hybridized probe. PCR is not used in this technique, so option (d) is correct.

Solution

In vitro clonal propagation, or micropropagation, involves the use of microscopy to observe and manipulate plant tissues and cells under sterile conditions. Techniques like PCR, RAPD, Northern blotting, and electrophoresis are not directly involved in the clonal propagation process, so option (d) is correct.

Solution

Chlorella is a unicellular green alga used as a food supplement for humans due to its high nutritional value. NCERT XII chapter Biotechnology and its Applications highlights Chlorella as a potential food source, so option (b) is correct.

Solution

Plasmids can clone only small DNA fragments due to their limited size. Bacterial artificial chromosomes, yeast artificial chromosomes, and cosmids can accommodate larger DNA inserts, so option (c) is correct.

Solution

Both apical and axillary meristems are used to obtain virus-free healthy plants from a diseased plant through tissue culture. These regions are less likely to be infected by viruses, making them ideal for this purpose. NCERT XII chapter Biotechnology and its Applications discusses this technique, so option (c) is correct.

Solution

The DNA molecule to which the gene of interest is integrated for cloning is called vector. www.vedantu.com 18

Solution

Golden rice is nutritionally enriched rich and is meant for biosynthesis of vitamin A.

Solution

Clostridium butylicum is used for the production of butyric acid. Candida lipolyticum is the source of lipase.

Solution

Biosynthetic stage for synthesis of product in recombinant DNA technology is called upstreaming process while after completion of biosynthetic stage, the product has to be subjected through a series of processes which include separation and purification are collectively referred to as downstreaming processing.

Solution

In recombinant DNA technology, selectable markers helps in identifying and eliminating non-transformants and selectively permitting the growth of the transformants.

Solution

Saccharomyces cerevisiae is commonly called Brewer’s yeast. It causes fermentation of carbohydrates producing ethanol.

Solution

Ethidium bromide is used to stain the DNA fragments and will appear as orange coloured bands under UV light.

Solution

Biopiracy refers to the unauthorised use of bioresources by multinational companies and organisations without permission from the concerned country and its people. NCERT XII chapter Biotechnology and its Applications defines biopiracy in this context, so option (b) is correct.

Solution

The Genetic Engineering Appraisal Committee (GEAC) is the apex body responsible for assessing the safety of introducing genetically modified organisms for public use in India. This is in line with the guidelines and regulatory framework described in NCERT XII Biotechnology and its Applications, so option (d) is correct.

Solution

The controversy involves the patenting of Basmati rice by a foreign company, despite its long-standing presence in India. This issue is discussed in NCERT XII Biotechnology and its Applications, making option (d) correct.

Solution

Ref. XII NCERT Chapter- 15, Page No. 267

Solution

Ref. XII NCERT Chapter- 16, Page No. 281

Solution

Ref. XII NCERT Chapter- 06, Page No. 96

Solution

Ref. XII NCERT Chapter- 05, Page No. 83 (some part is out of NCERT) 1% crossover = 1 Centimorgan = 1 map unit

Solution

Ref. XI NCERT Chapter- 02, Page No. 26-27

Solution

Ref. XII NCERT Chapter- 05, Page No. 91 24 SPACE FOR ROUGH WORK

Solution

Each restriction enzyme recognizes and cuts DNA at specific palindromic sequences, not by inspecting the length of a DNA sequence. Therefore, option (a) is incorrect. NCERT XII chapter Biotechnology and its Applications explains that restriction enzymes recognize specific nucleotide sequences and cleave DNA at these sites.

Solution

- Bt cotton is genetically modified to express toxins from $\text{Bacillus thuringiensis}$ (iv).
- Adenosine deaminase deficiency is treated by gene therapy (i).
- RNAi (RNA interference) is used for cellular defence (ii).
- PCR (Polymerase Chain Reaction) is used for the detection of HIV infection (iii).

Solution

Activated sludge, which contains microorganisms, is added to the anaerobic sludge digester to further break down organic matter in the sewage. NCERT XII chapter Biotechnology and its Applications describes this process as part of secondary treatment, so option (d) is correct.

Solution

The origin of replication (Ori site) controls the copy number of the linked DNA in a vector. This site is essential for the initiation of DNA replication and determines how many copies of the plasmid are made within the host cell, so option (b) is correct.

Solution

Bt cotton, developed by introducing the toxin gene from $\text{Bacillus thuringiensis}$, is resistant to insect pests. This gene produces a protein that is toxic to certain insects, making Bt cotton effective against insect pests, so option (a) is correct.

Solution

Separated DNA fragments in gel electrophoresis are visualized using ethidium bromide, which intercalates with DNA and fluoresces under UV radiation. NCERT XII chapter Biotechnology and its Applications describes this technique, so option (b) is correct.

Solution

- $\text{Bacillus thuringiensis}$ produces Cry proteins.
- $\text{Thermus aquaticus}$ is the source of the DNA polymerase used in PCR.
- $\text{Agrobacterium tumefaciens}$ is used as a cloning vector.
- $\text{Salmonella typhimurium}$ was used in the construction of the first rDNA molecule.

Solution

EcoRI recognizes the palindromic sequence 5' - GAATTC - 3' and its complementary strand 3' - CTTAAG - 5'. This sequence is cleaved by EcoRI to produce sticky ends, as described in NCERT XII Biotechnology and its Applications, so option (a) is correct.

Solution

- Protoplast fusion results in somatic hybrids, which can produce somaclones.
- Plant tissue culture exploits the totipotency of plant cells.
- Meristem culture is used to produce virus-free plants.
- Micropropagation involves the rapid multiplication of plants, producing somaclones.
Thus, the correct option is (b).

Solution

PCR is used for molecular diagnosis, gene amplification, and detection of gene mutations, but not for the purification of isolated proteins. NCERT XII chapter Biotechnology and its Applications outlines these applications, so option (c) is correct.

Solution

Chilled ethanol is used to precipitate DNA during purification in recombinant DNA technology. This process helps in separating DNA from other cellular components, making option (b) correct.

Solution

Gene therapy involves altering genes in an individual’s cells to treat or prevent disease, often through gene targeting and amplification. NCERT XII chapter Biotechnology and its Applications defines gene therapy as the introduction of normal genes into cells to correct genetic disorders, so option (b) is correct.

Solution

The correct sequence of steps in PCR is denaturation, annealing, and extension. NCERT XII chapter Biotechnology and its Applications outlines this order: denaturation separates the DNA strands, annealing allows primers to bind, and extension synthesizes new DNA strands, so option (a) is correct.

Solution

When the PstI restriction enzyme is used to insert a gene into the pBR322 plasmid, it cuts within the ampicillin resistance gene (${\text{amp}}^R$), disrupting it. As a result, the recombinant plasmid will not confer ampicillin resistance to the host cell, making option (a) correct.

Solution

Biofortification aims to improve the nutritional quality of crops by enhancing their protein, vitamin, and micronutrient content, but not by improving resistance to diseases. NCERT XII chapter Biotechnology and its Applications outlines the objectives of biofortification, so option (b) is correct.

Solution

- Aspergillus niger produces citric acid.
- Acetobacter aceti produces acetic acid.
- Clostridium butylicum produces butyric acid.
- Lactobacillus produces lactic acid.

Solution

ELISA (Enzyme-Linked Immunosorbent Assay) is highly effective for early detection of diseases due to its sensitivity and specificity in detecting antigens or antibodies. NCERT XII chapter Biotechnology and its Applications highlights ELISA as a key diagnostic tool, so option (c) is correct.

Solution

If very high temperature is not maintained at the beginning of PCR, the denaturation step, where double-stranded DNA is separated into single strands, will be affected first. NCERT XII chapter Biotechnology and its Applications outlines the PCR process, emphasizing the importance of high temperature for denaturation, so option (c) is correct.

Solution

As the product of ‘i’ gene binds with the operator region and blocks the transcription and translation of z, y and a genes. It’s product is prevented from binding to the operator by attaching it with the inducer. As the inducer can now no more capable of binding with the repressor, thus, in all the cases, operator always gets attached with the repressor thereby preventing the transcription and transmission of z, y and a. Even in the presence of lactose, transcription and translation of z, y and a would not occur.

Solution

Option (2) is the correct answer as genetically engineered insulin has A -peptide and B-peptide chains of insulin which are produced separately in E.coli, then they are extracted and combined by creating disulphide bond between them. Statement (a) is incorrect as genetically engineered insulin does not have an extra stretch of C-peptide. Statement (c) is incorrect as insulin obtained from cattles and pigs is not genetically engineered insulin. Statement (d) is incorrect because conversion of pro-insulin to insulin is not required during production of insulin by genetic engineering as A-peptide and B-peptide chains are produced separately. Statement (e) is incorrect as a llergic reactions to insulin are mostly seen when the insulin is obtained from animals.

Solution

Option (4) is the correct answer. Cloning vectors are the carriers of the desired gene in the host cell. The features desirable in a cloning vector are:- • Presence of origin of replication • Presence of marker genes • Presence of very few, preferably single recognition site for the commonly used restriction enzymes

Solution

The correct answer is option (3) as specific Bt toxin genes were isolated from Bacillus thuringiensis and incorporated into the several crop plants such as cotton. The choice of genes depends upon the crop and the targeted pest as most Bt toxins are insect-group specific. The toxin is coded by a gene named cry. There are a number of them, for example, the proteins encoded by the genes cry IAc and cry IIAb control the cotton bollworms, that of cry IAb controls corn borer.

Solution

The correct answer is option (3) as α– I antitrypsin → Is used for treatment of Emphysema Cry I Ab gene → Controls corn borer Cry I Ac gene → Controls cotton bollworms Enzyme replacement therapy → Can be used as treatment option in ADA deficiency.

Solution

Eli Lilly used the bacterium $\text{Escherichia coli}$ to produce human insulin through genetic engineering. NCERT XII chapter Biotechnology and its Applications describes this process, so option (a) is correct.