NEET Previous Year Questions (2016-2024): Biotechnology & Its Applications | Biology Class 12 PDF Download

2024

Q1: Match List I with List II    (NEET 2024)

Choose the correct answer form the options given below:
(a) A-II, B-I, C-IV, D-III
(b) A-III, B-I, C-II, D-IV
(c) A-III, B-IV, C-I, D-II
(d) A-II, B-IV, C-I, D-III
Ans: (c)
To provide the correct answer, let's evaluate each option by matching the items from List I with their corresponding descriptions from List II:
α-I antitrypsin - This is a protease inhibitor and its deficiency leads to emphysema due to the degradation of the lung tissue. Therefore, α-I antitrypsin corresponds to Emphysema (III).
Cry IAb - Part of a family of proteins from Bacillus thuringiensis used as a biological pesticide. Cry IAb is notably effective against certain types of Lepidoptera, including the European Corn Borer (IV).
Cry IAc - This is also a protein from Bacillus thuringiensis and is notably effective against Cotton Bollworm (I).
Enzyme replacement therapy - Typically used for treating deficiencies in certain enzymes; one prevalent example is Adenosine Deaminase (ADA) deficiency, which leads to immune deficiencies (II).
Let's match these back to the original options provided:
A-III (α -I antitrypsin matches with Emphysema)
B-IV (Cry IAb matches with Corn Borer)
C-I (Cry IAc matches with Cotton Bollworm)
D-II (Enzyme replacement therapy matches with ADA deficiency)
Based on these matches, the correct option would be: Option C: A-III, B-IV, C-I, D-II

Q2: Which of the following statements is incorrect?     (NEET 2024)
(a) A bio-reactor provides optimal growth conditions for achieving the desired product
(b) Most commonly used bio-reactors are of stirring type
(c) Bio-reactors are used to produce small scale bacterial cultures
(d) Bio-reactors have an agitator system, an oxygen delivery system and foam control system
Ans: (c)
The incorrect statement among the provided options is: Option C.
Bio-reactors, also known as fermenters, are primarily utilized for scaling up microbial processes to industrial scales. They are designed to support the growth of a high density of cells and microbes under controlled conditions to produce large volumes of biochemical products such as enzymes, pharmaceuticals, and other biologically active compounds. While bio-reactors can technically be used for small-scale laboratory experiments, their main application and design focus is on large-scale production.
Other Options:
Option A: This statement is correct. Bio-reactors are specifically designed to provide optimal conditions such as temperature, pH, oxygen supply, and nutrients for the growth of microorganisms or cells, which helps in achieving a higher yield of the desired product.
Option B: This statement is also true. The most common type of bio-reactors used in industrial processes are of the stirred type, which have mechanical agitators to evenly distribute nutrients and maintain uniform conditions within the tank.
Option D: True, bio-reactors often include several essential systems: an agitator system for mixing, an oxygen delivery system to provide sufficient respiration for aerobic organisms, and a foam control system to prevent the formation of excessive foam, which could interfere with the operation of the reactor.
Thus, the incorrect statement about the typical scale and focus of bio-reactor use is Option C.

Q3: Which of the following are fused in somatic hybridization involving two varieties of plants?    (NEET 2024)
(a) Callus
(b) Somatic embryos
(c) Protoplasts
(d) Pollens
Ans: (c)
In somatic hybridization, the fusion of protoplasts from different plant varieties or species is a key technique. Protoplasts are plant cells that have had their cell walls enzymatically removed, exposing the cell membrane. This condition allows for the direct fusion of cellular contents including the nucleus and cytoplasm from different cells, facilitating recombination and the formation of a hybrid cell. The process of fusion typically involves techniques such as electrofusion or chemical treatments to encourage the protoplasts to merge.

Looking at the options provided:

• Option A: Callus – This is not correct. A callus is a mass of unorganized plant cells that are generally not involved in fusion during somatic hybridization but are rather a product of the culture of somatic cells.
• Option B: Somatic embryos – These are not the direct subjects of fusion in somatic hybridization. Somatic embryos can develop from hybrid cells, but they themselves are not fused; they are derived from somatic cells under appropriate conditions.
• Option C: Protoplasts – This is correct. Protoplasts are indeed what are fused in somatic hybridization to combine the genetic material from two different plants or varieties.
• Option D: Pollens – These do not fuse in somatic hybridization. Pollen fusion is more relevant to sexual reproduction and breeding, not somatic cell procedures.

Therefore, the correct answer is Option C: Protoplasts.

Q4: Given below are two statements:       (NEET 2024)
Statement I : Bt toxins are insect group specific and coded by a gene cry IAc.
Statement II : Bt toxin exists as inactive protoxin in B. thuringiensis. However, after ingestion by the insect the inactive protoxin gets converted into active form due to acidic pH of the insect gut.
In the light of the above statements, choose the correct answer from the options given below:
(a) Both Statement I and Statement II are true
(b) Both Statement I and Statement II are false
(c) Statement I is true but Statement II is false
(d) Statement I is false but Statement II is true
Ans: (c)
Sol: 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.

Q5: The capacity to generate a whole plant from any cell of the plant is called:    (NEET 2024)
(a) Totipotency
(b) Micropropagation
(c) Differentiation
(d) Somatic hybridization
Ans: (a)
Sol: Totipotency is defined as the capacity to generate a whole plant from any cell of the plant. 

2023

Q1: During the purification process for recombinant DNA technology, addition of chilled ethanol precipitates out
(a) DNA
(b) Histones
(c) Polysaccharides
(d) RNA                                            (NEET 2023)
Ans: (a)

• Option (A) is the correct answer as, during isolation of the genetic material, purified DNA ultimately precipitates out after the addition of chilled ethanol.
• Option (B) is not the answer as, proteins can be removed by treatment with proteases.
• Option (D) is not the answer as RNA can be removed by treatment with ribonuclease.

Q2: In gene gun method used to introduce alien DNA into host cells, microparticles of ________ metal are used.
(a) Zinc
(b) Tungsten or gold
(c) Silver
(d) Copper                 (NEET 2023)
Ans: (b)
Option (B) is the correct answer because in gene gun method, microparticles of tungsten or gold are used. Gold or tungsten are inert in nature so they do not alter the chemical composition of cells.

Q3: Main steps in the formation of Recombinant DNA are given below. Arrange these steps in a correct sequence.
A. Insertion of recombinant DNA into the host cell
B. Cutting of DNA at specific location by restriction enzyme
C. Isolation of desired DNA fragment
D. Amplification of gene of interest using PCR
Choose the correct answer from the options given below :
(a) C, A, B, D
(b) C, B, D, A
(c) B, D, A, C
(d) B, C, D, A          (NEET 2023)
Ans: (d)
The correct answer is option (D) because recombinant DNA technology involves several steps in specific sequence such as isolation of DNA, fragmentation of DNA by restriction endonucleases, isolation of desired DNA fragment, ligation of the DNA fragment into a vector, transferring the recombinant DNA into the host, culturing the host cells in a medium at large scale and extraction of the desired product.

2022

Q1: Milk of transgenic ‘Cow Rosie’ was nutritionally more balanced product for human babies than natural cow milk because it contained:
(a) Human enzyme Adenosine Deaminase (ADA)
(b) Human protein α-1-antitrypsin
(c) Human alpha-lactalbumin
(d) Human insulin-like growth factor      (NEET 2022 Phase 2)
Ans:  (c)

• Option (c) is the correct answer because the first transgenic cow Rosie produced human protein-enriched milk. The milk contained the human alpha-lactalbumin and was nutritionally a more balanced product for human babies than natural cow milk.
• Option (a) is not the correct answer because ADA deficiency in humans can be cured by gene therapy.
• Option (b) is not the correct answer because transgenic sheep produced human α-1-antitrypsin that is used to treat emphysema.
• Option (d) is not the correct answer because insulin-like growth factor was not present in Rosie’s milk.

Q2: In the following palindromic base sequences of DNA, which one can be cut easily by particular restriction enzyme?
(a) 5'GATACT3' ; 3'CTATGA5'
(b) 5'GAATTC3' ; 3'CTTAAG5'
(c) 5'CTCAGT3' ; 3'GAGTCA5'
(d) 5'GTATTC3' ; 3'CATAAG5'      (NEET 2022 Phase 1)
Ans: (b)
Option (b) is the correct answer as a palindromic DNA sequence is a DNA sequence of base pairs that reads same on the two strands when orientation of reading is kept the same. Out of the four options, option (b) is the only palindromic sequence.
5'GAATTC3'
3'CTTAAG5'

Q3: In gene therapy of adenosine deaminase (ADA) deficiency, the patient requires a periodic infusion of genetically engineered lymphocytes because:      (NEET 2022 Phase 1)
(a) Gene isolated from marrow cells producing ADA is introduced into cells at embryonic stages
(b) Lymphocytes from patient's blood are grown in culture, outside the body.
(c) Genetically engineered lymphocytes are not immortal cells.
(d) Retroviral vector is introduced into these lymphocytes.
Ans: (c)

• Option (d) is the correct answer as genetically engineered lymphocytes are not immortal cells and die after some time.
• Option (c) is not the correct answer as the lymphocytes from patient's blood are grown in culture, outside the body but it is not the correct reason.
• In option (b), if the gene isolated from bone marrow cells producing ADA is introduced into cells at early embryonic stages, it could be a permanent cure.

Q4: Statements related to human Insulin are given below.    (NEET 2022 Phase 1)
Which statements is/are correct about genetically engineered Insulin?
(a) Pro-hormone insulin contain extra stretch of C-peptide
(b) A-peptide and B-peptide chains of insulin were produced separately in E.coli, extracted and combined by creating disulphide bond between them.
(c) Insulin used for treating Diabetes was extracted from Cattles and Pigs.
(d) Pro-hormone Insulin needs to be processed for converting into a mature and functional hormone.
(e) Some patients develop allergic reactions to the foreign insulin.
Choose the most appropriate answer from the options given below :
(a) (a), (b) and (d) only
(b) (b) only
(c) (c) and (d) only
(d) (c), (d) and (e) only
Ans: (b)

• Option (b) 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 allergic reactions to insulin are mostly seen when the insulin is obtained from animals.

2021

Q1: When gene targeting involving gene amplification is attempted in an individual's tissue to treat disease, it is known as:  
(a) Molecular diagnosis
(b) Safety testing
(c) Biopiracy
(d) Gene therapy     (NEET 2021)
Ans: (d) 
The correct option is (d)

• Gene therapy is a collection of methods that allows correction of a gene defect that has been diagnosed in a child/embryo.
• Biopiracy is the term used to refer to the use of bio-resources by multinational companies and other organisations without proper authorisation from the countries and people concerned without compensatory payment.
• Molecular diagnosis refers to the act or process of determining the nature and cause of a disease.

Q2: With regard to insulin choose correct options.      (2021)
(a) C-peptide is not present in mature insulin.
(b) The insulin produced by rDNA technology has C-peptide.
(c) The pro-insulin has C-peptide.
(d) A-peptide and B-peptide of insulin are interconnected by disulphide bridges.
Choose the correct answer from the options given below.
(a) (a), (c) and (d) only
(b) (a) and (d) Only
(c)  (b) and (d) only
(d) (b) and (c) only
Ans: (a)

• Insulin is synthesized as a pro-hormone which contains A-chain, B-chain and an extra stretch called the C-peptide.
• C-peptide is not present in mature insulin called humulin.
• Chains A and B are connected by interchain disulphide bridges.

2020

Q1: Match the following columns and select the correct option.      (NEET 2020)


Ans: (c)
Bt cotton the specific Bt toxin gene was isolated from Bacillus thuringiensis. The first clinical gene therapy was given in 1990 to a 4-year old girl with adenosine deaminase (ADA) deficiency. RNAi (RNA interference) takes place in all eukaryotic organisms as a method of cellular defense. PCR is now routinely used to detect HIV in suspected AIDS patients

Q2: Which of the following statements is not correct?      (NEET 2020)
(a) The functional insulin has A and B chains linked together by hydrogen bonds.
(b) Genetically engineered insulin is produced in E-Coli.
(c) In man insulin is synthesised as a proinsulin.
(d) The proinsulin has an extra peptide called C-peptide.
Ans: (a)
Functional insulin has A and B chains linked together by disulphide bridges.

2019

Q1: Which of the following glucose transporters is insulin-dependent?      (NEET 2019)
(a) GLUT III
(b) GLUT IV
(c) GLUT I
(d) GLUT II
Ans: (b)
GLUT IV is insulin dependent glucose transporter which increases uptake of glucose.

2018

Q1: Which of the following is commonly used as a vector for introducing a DNA fragment in human lymphocytes?     (NEET 2018)
(a) Retrovirus
(b) Ti plasmid
(c) λ phage
(d) pBR322
Ans: (a)
Retrovirus is commonly used as vector for introducing a DNA fragment in human lymphocyte.

Q2: In India, the organisation responsible for assessing the safety of introducing genetically modified organisms for public use is    (NEET 2018)
(a) Indian Council of Medical Research (ICMR)
(b) Council for Scientific and Industrial Research (CSIR)
(c) Research Committee on Genetic Manipulation (RCGM)
(d) Genetic Engineering Appraisal Committee (GEAC)
Ans: (d)
Indian government has set up organisation such as GEAC (Genetic Engineering Appraisal Committee) which makes decisions regarding the validity of GM research and safety of introducing GM organisms for public services.

Q3: Use of bioresources by multinational companies and organisations without authorisation from the concerned country and its people is called    (NEET 2018)
(a) Bio-infringement
(b) Biopiracy
(c) Biodegradation
(d) Bioexploitation
Ans: (b)
Biopiracy refers to the use of bio-resources by multinational companies and other organizations without proper authorization from the countries and people concerned.

Q4: A ‘new’ variety of rice was patented by a foreign company, though such varieties have been present in India for a long time, This is related to    (NEET 2018)
(a) Co-667
(b) Sharbati Sonora
(c) Lerma Rojo
(d) Basmati
Ans: (d)
In 1997, an American company got patent rights on Basmati rice through the US Patent and Trademark Office. This allowed the company to sell a ‘new’ variety of Basmati.

2016

Q1: Which kind of therapy was given in 1990 to a four-year-old girl with adenosine deaminase (ADA) deficiency?    (NEET 2016 Phase 2)
(a) Gene therapy
(b) Chemotherapy
(c) Immunotherapy
(d) Radiation therapy
Ans: (a)
Gene therapy is a technique of genetic engineering which involves replacement of a faulty/disease causing gene by a normal healthy functional gene. The first clinical gene therapy was given in 1990 to a 4-year old girl with adenosine deaminase (ADA) deficiency. This enzyme is very important for the immune system to function. The deficiency of this enzyme can lead to severe combined immune deficiency (SCID).

Q2: The two polypeptides of human insulin are linked together by    (NEET 2016 Phase 1)
(a) Covalent bond
(b) Disulphide bridges
(c) Hydrogen bonds
(d) Phosphodiester bond
Ans: (b)
Insulin is a hormone consisting of 2 polypeptide chains. Each chain is composed of a specific sequence of amino acid residues connected by peptide bonds. In humans, chain A has 21 amino acids, and chain B has 30. Post translational modifications result in the connection of these two chains by disulfide bridges. Cysteine residues on A7 and B7, as well as A20 to B19 are covalently connected by disulfide bridges.

Q3: Which part of the tobacco plant is infected by Meloidogyne incognita?     (NEET 2016 Phase 1)
(a) Stem
(b) Root
(c) Flower
(d) Leaf 
Ans: (b)
Meloidogyne incognita is a nematode (roundworm) in the family Heteroderidae. It is commonly called the “southern rootknot nematode” or the “cotton root-knot nematode”.

2015

Q1: Golden rice is a genetically modified crop plant where the incorporated gene is meant for biosynthesis of :    (NEET 2015 / AIPMT 2015 )
(a) Vitamin C
(b) Omega 3
(c) Vitamin A
(d) Vitamin B
Ans: (c)
Golden rice (Oryza sativa) is a genetically modified crop. It biosynthesizes β - carotene which is the precursor of vitamin-A.

Q2: In Bt cotton, the Bt toxin present in plant tissue as pro-toxin is converted into active toxin due to:  (NEET 2015 / AIPMT 2015 )
(a) Acidic pH of the insect gut
(b) Action of gut micro-organisms
(c) Presence of conversion factors in insect gut
(d) Alkaline pH of the insect gut
Ans: (d)
Bt toxin are solubilised in alkaline pH of the insect gut causing death.

Q3: The crops engineered for glyphosate are resistant/ tolerant to:    (NEET 2015 / AIPMT 2015 )
(a) Bacteria
(b) Insects
(c) Herbicides
(d) Fungi
Ans: (c)
Today plants having the broad leaves are made resistant to a powerful biodegradable herbicide glyphosate. It is an active ingredient of Round Up ready plant. It disturbs the working of EPSP synthetase enzyme. If it is taken up by crop plants they will die. So, the bioengineers have transferred gene for synthesis of EPSP synthetase enzyme to crop plant.

Q4: Which body of the Government of India regulates GM research and safety of introducing GM organisms for public services ?      (NEET 2015 / AIPMT 2015 Cancelled Paper)
(a) Indian Council of Agricultural Research
(b) Genetic Engineering Approval Committee
(c) Research Committee on Genetic Manipulation
(d) Bio-safety committee
Ans: (b)
Genetic modification of organisms can have unpredictable results, when such organisms are introduced into the ecosystem. Therefore, the Indian Government has set up organizations such as GEAC (Genetic Engineering Approval Committee), which makes decisions regarding the validity of GM research and the safety of introducing GM-organisms for public services.

2014

Q1: The first human hormone produced by recombinant DNA technology is:    (NEET 2014 / AIPMT 2014 )
(a) Insulin
(b) Estrogen
(c) Thyroxin
(d) Progesterone
Ans: (a)
Mammalian hormones were among the first products prepared in bacteria by r-DNA technology. Human insulin and human growth hormone are earliest examples.

Q2: To obtain virus−free healthy plants from a diseased one by tissue culture technique, which part/parts of the diseased plant will be taken ?    (NEET 2014 / AIPMT 2014 )
(a) Epidermis only
(b) Palisade parenchyma
(c) Both apical and axillary meristems
(d) Apical meristem only
Ans: (c)
To obtain virus - free healthy plants from a diseased one by tissue culture technique, both apical and axillary meristems of the diseased plant will be taken. Plant tissue culture is used to maintain or grow plant cells, tissues or organs under sterile conditions on a nutrient culture medium of known composition. Plant tissue culture is widely used to produce clones of a plant in a method known as micro propagation.