Biotechnology & Its Applications: Important Questions

CBSE Class 12 Biology Biotechnology and its Applications have been provided in this article along with their detailed solutions as per the latest CBSE Board Curriculum. The important questions would assist the students to understand all the important topics covered in the chapter like Biotechnology, Applications of Biotechnology, Transgenic Animals, Production of Antibiotics, Cloning, Recombinant DNA Technology, etc. 

Biotechnology refers to the use of microorganisms, plant cells, or animal cells or their components to manufacture products and technologies that help human welfare. Biotechnology has a wider range of applications in the medical and agricultural industries. With the help of it, crops can be genetically modified and their quality can be improved. Also, gene therapy is one of the advantages of biotechnology, in this crops are produced by incorporating desired characteristics from the plants, which helps in producing disease-free crops resistant to pests. Biotechnology helps develop sustainable technologies. In the field of medicine, biotechnology is used in the production of therapeutical proteins and drugs.

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Very Short Answer Questions (1 Mark Questions) 

Ques. What are the applications of biotechnology? 

Ans. The applications of Biotechnology are-

• Treatment of diseases.
• Preparation of processed food that is fortified. 

Ques. What are probes? 

Ans. Probes are single-stranded DNA or RNAs tagged with a radioactive molecule, complementary to DNA in a clone of the cells.

Ques. Bt-toxin exists in which form?

Ans.  Bt-toxin exists in inactive Protonix form.

Ques. Name two diseases that can be treated by producing biological compounds in transgenetic animals.

Ans. Cystic fibrosis, rheumatoid arthritis, Alzheimer’s disease, cancer, and emphysema are some diseases that can be treated by producing biological compounds in transgenetic animals. 

Ques. How is inactive Bt-toxin converted into an active form? 

Ans. The inactive toxin is converted into an active form due to the alkaline ph of the gut of insects which solubilizes the crystal converting the toxic to the active form. 

Ques. Name a few forms of cry gene.

Ans. Some forms of ‘cry’ are cry IAC, cry IAB, and cry IIAB.

Ques. Name the genetically engineered human insulin.

Ans. Humulin is genetically engineered human insulin. 

Ques. Define a patent.

Ans. A Patent is described as a government protection right for the biological material innovators, that grants them the exclusive right to manufacture, exploit, use and sell an innovation for some time. 

Ques. Expand GEAC.

Ans. The genetic Engineering Approval Committee is the expanded form of GEAC.

Read More: Genetic Engineering Appraisal Committee (GEAC)

Ques. Name the first transgenetic cow.

Ans. Rosie was the name of the first-ever transgenic cow. 

Ques. Give the name of the recombinant vaccine.

Ans. The Hepatitis B vaccine is a recombinant vaccine. 

Ques. Name the vaccine that was being tested in mice.

Ans. The Polio vaccine was being tested on mice.

Ques. Name any disease against which a vaccine is developed by Recombinant DNA technology. 

Ans. A disease against which vaccines are developed by Recombinant DNA technology is Hepatitis B.

Ques. Name the diseases for which transgenic mice were used as model organisms.

Ans. Rheumatoid arthritis and cystic fibrosis are the two diseases in which transgenic mice were used as model organisms.

Ques. What is the difference between ‘Cry’ & ‘CRY’?

Ans. A cry is a gene that codes for Bt-toxin which is an insecticidal protein, whereas, on the other hand, CRY is the protein coded by cry genes. 

Ques. What are competent cells? What does the word “competent refer to? 

Ans. Competent cells are the cells that allow the foreign DNA to incorporate into host cell walls. Competent means the ability of a cell to enter foreign DNA. 

Ques. What is the principle of biotechnology? 

Ans. Modern biotechnology started with two crucial technologies- 

• Chemical engineering.
• Genetic engineering.

Biotechnology

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Short Answer Questions (2 Marks Questions)

Ques. What are the different types of biotechnology? 

Ans. Different types of Biotechnology are as follows-

• Medical Biotechnology 
• Plant Biotechnology
• Biopharma 
• Food Biotechnology
• Marine Biotechnology
• Animals biotechnology
• Environmental Biotechnology
• Agriculture Biotechnology
• Industrial Biotechnology

Ques. Give a few characteristics of GMOs.

Ans. Genetically Modified Organisms are GMOs, and here are a few characteristics of GMOs: 

• GMOs show enhanced nitrogen fixation.
• GMOs are capable of producing enhanced metabolites and GMOs are capable of producing pharmaceutically useful proteins 
• GMOs are used for crop protection to control insects, fungal diseases, and frost damage. 

Ques. State the difference between diagnostics and therapeutics. Give one example for each category.

Ans. The difference between diagnostics and therapeutics is 

Ques. What are the advantages of molecular diagnostic over conventional methods?

Ans. Here are some of the advantages of molecular over conventional methods-

• Using the conventional method, early diagnosis is not possible, but by using DNA technology and PCR early diagnosis is possible. 
• It is also used to detect mutations in patients suspected of cancer.
• Molecular diagnostic is used to detect mutation in suspected cancer patients

Read More: Genetic Engineering

Ques. What is a polymerase chain reaction? What are the steps involved and what mention its applications? 

Ans. Polymerase chain reaction (PCR) is a method used to make copies of a specific piece of DNA, from a tiny amount of the DNA. The purpose of polymerase chain reaction is to make enough of the target DNA region that is analyzed or used in some or the other way. In PCR the basic steps are Denaturation, Annealing, and Extension.

Steps in Polymerase Chain Reaction

Ques. Mention any four applications of Biotechnology in the field of agriculture. 

Ans. Agriculture Biotechnology is a set of scientific techniques that helps to improve the quality of plants, microorganisms, and animal DNA. 

• Better Crop Protection
• Chemical Tolerance 
• Increase in nutrition value
• Fresh food with better taste

Ques. What is a gene library? 

Ans. A gene library is a collection of different types of DNA sequences from different organisms. A Gene library is a collection of DNA those are cloned and designed so that there is a higher probability of finding a particular piece of the source DNA in the respective collection. All gene libraries are collections of DNA fragments that represent a system of interest. 

Ques. Why did bacterial toxins not kill the bacteria but only the insects? 

Ans.  Bt-toxin does not kill the bacterium that produces it, but it can kill the insects because the endotoxin that accumulates in the bacterium is an inactive precursor. It gets activated only alkaline gut of the insects. So that insect is unable to feed and thus consequently starved to death. 

Ques. Name some useful products obtained from animal cell lines 

Ans. Some of the most useful products used from animal cell lines are- the production of vaccines for influenza, mumps from chick embryo fluid, measles production of rubella, and rabies vaccines from the fluid of embryo of duck. 

Ques. What is meant by “biopiracy”, give an example of the same.

Ans. The practice of commercially exploiting biochemical or genetic materials that occur naturally is known as biopiracy, this is especially done to obtain patents that restrict the future use of the practice. For example biopiracy of African super sweet berries.

Ques. Explain the principle involved in ELISA.

Ans. The antigen-antibody interaction always uses an enzyme called an Antigen or Antibody. The activity in the enzyme is measured with the help of a calorimeter using a substance that changes color when modified by the use of the enzyme, after this the light is absorbed by the product formed and it is represented in numeric values 

Read More: Difference Between Antigen and Antibody

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Long Answer Questions (3 Marks Questions)

Ques. What is a probe? How it is used in molecular diagnostics? 

Ans. A probe is a single-stranded DNA sequence or RNA sequence that is used in the search for its complementary sequence in a sample of a genome. A probe is placed in contact with a sample under suitable conditions which allows the probe sequence to hybridize with its complementary sequence. 

• The probe is labeled with a radioactive or a chemical tag that allows its binding to be visualized, in a similar way. Radioactive material or fluorescent material can also be used to chemically attach it to a probe. And then we can use that probe to look for where certain mRNAs are expressed in a cell or a tissue. 
• We can also use probes to screen the genome to find out if there are extra copies, which often happen in cancers, or missing copies of certain parts of the genome, which happens in hereditary syndromes and cancers. since a probe is a single-stranded fragment of DNA or RNA of variable length, it is hybridized with its complementary DNA and thus can be detected by autoradiography. 

Read More: DNA Fingerprinting

Ques. How are the following used in biotechnology? 

• Recognition Sequence 
• Gel Electrophoresis 
• Plasmid Cell

Ans. (a) Recognition Sequence- A recognition site is a sequence of bases that are identified by the restriction of enzymes for cutting DNA at a specific site

(b) Gel Electrophoresis- Gel electrophoresis is a method that is used to separate mixtures of DNA, RNA, and protein according to molecular sizes. 

(c) Plasmid Cell- A plasmid cell is a small circular DNA molecule found in bacteria and microorganisms. Plasmids are physically separated from chromosomal DNA and replicate independently. 

Ques. Name and explain the techniques used in the separation and isolation of DNA fragments to be used in recombinant DNA technology. 

Ans. DNA fragments that are formed by the use of restriction endonuclease are separated by gel electrophoresis. The technique is based on the principle, that when a charged molecule is placed in an electric field the particles move from positive or negative sides according to the change in their charges. 

Since DNA fragments are negatively-charged molecules, they moved towards the anode under an electric field through the medium, DNA fragments separate according to their size due to the sieving effect of agarose gel. The DNA fragments after separating can be viewed by staining the DNA with some ethidium bromide followed by exposure to UV radiation the separated bands of the DNA are cut and extracted from gel pieces and this is known as elution. The electric field is applied to the DNA fragments that are negatively charged move through the gel towards the anode and get separated. 

Recombinant DNA Technology

Ques. A vector is engineered with three features, which facilitate its cloning within the host cell. List down and mention the three features and explain each of them

Ans. Features that facilitate the cloning of vectors are

• Origin of Replication (Ori): The origin of Replication (Ori) is the sequence of DNA from where replication starts. Any piece of alien/foreign DNA linked to it is made to replicate within the host cell. It also decides the copy number of the linked DNA.
• Selectable Marker: Selectable marker is a marker gene, which helps in selecting the host cells, which are transformants/recombinants from the non-recombinant ones.
• Cloning Site: A cloning site is a unique recognition site in a vector to link the foreign DNA. The presence of a particular cloning/recognition site helps the particular restriction enzyme to cut the vector DNA. A single recognition site is commonly referred to find the presence of clones in the DNAs. 
• Small Size of the Vector: The small size helps in the introduction of the DNA into the host very easily. The smaller the size the more easily DNA can be hosted by the vector. 

Read More: DNA Replication

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Very Long Answer Questions (5 Marks Questions)

Ques. In the given figure, Form (A) and Form (B) represent different forms of a proteinaceous hormone secreted by the pancreas in mammals.

(a) Explain what type of bonding is present between chains of this hormone.
(b) What are these forms (A) and form (B)? How do these firms differ from each other?
(c) How was this hormone produced by Eli Lilly using rDNA technology?

Ans. (a) The type of bonding is of Disulphide bond, between the chains of the hormones. 

(b) Form (A) is proinsulin and form (B) is Mature proinsulin that contains an extra stretch called c peptide which is absent in mature insulin. 

(c) The Eli Lilly company prepared two sequences that correspond to the A and B peptide chains of the human insulin and introduces them to the plasmid E.coli to produce insulin chains, Chain A and B were produced separately a d were combined by creating a disulphdisulfideo form insulin.

Ques. Clinical gene therapy is given to a 4 years old patient for an enzyme that is crucial for the immune system to function.

Observe the therapeutical flow chart and answer the following:

(a) Complete the missing steps in (B) and (D).
(b) Identify the disease to be cured.
(c) The above method is not a complete solution to the problem, why?
(d) How have scientists developed a method to cure this disease permanently? 

Ans. (a) Step (B): Lymphocytes are grown in a culture medium and Step (D): Infusion of genetically engineered lymphocytes into patients.

(b) Adenosine Deaminase Deficiency (ADA) 

(c) As explained genetically deaminase lymphocytes are not immortal, the patient requires a periodic infusion of cells.

(d) If the gene is isolated from bone marrow, cells producing ADA are introduced into cells at early embryonic stages, and it could be a permanent cure.

Read More: Cloning Vector

Ques. What are the steps involved in the synthesis of genetically engineered insulin?

Ans. The steps involved in Insulin production are detailed below-

• For the synthesis of Insulin, RNA is extracted from β−β−cells of islets of Langerhans of the pancreas and the insulin-producing gene is isolated.
• With the help of enzyme Reverse transcriptase, single-stranded DNA complementary to mRNA is synthesized the second strand of DNA complementary to the first is synthesized with enzyme DNA polymerase. An extracted DNA plasmid from a bacterium is then cut with a restriction enzyme forming a plasmid vector. 
• The two strands of copy DNA are joined to the plasmid by using an enzyme called terminal transferase.
• The two ends of DNA get annealed by an enzyme called ligase thus ends of inserted DNA & plasmid are sealed & a new circular plasmid is formed. This resultant is a molecule of recombinant DNA.
• This recombinant DNA is then inoculated in a new bacterial cell of E-coli & inserted in a bacterial gene after having been cut by a restriction enzyme. The recombinant bacteria, then, multiplies in a fermentation tank and produces human insulin. 
• The bacterial cells of both cultures are lysed with appropriate chemicals after the proper expression of genes. The fragments of insulin are then separated from the enzyme by cyanogen bromide, the insulin is then extracted, purified, and bottled by the performer and is ready to be injected into diabetic patients.

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