Biotechnological Applications in Medicine Questions in English

(C) $Pseudomonas \text{ } putida$ is a genetically engineered bacterium, often referred to as a "super bug".
It possesses the unique ability to break down complex hydrocarbons found in crude oil.
This property makes it highly effective in the bioremediation of oil spills in marine and terrestrial environments.

(C) Gene therapy is a technique that modifies a person's genes to treat or cure disease.
Option $(A)$ refers to the production of edible vaccines using transgenic plants.
Option $(B)$ refers to the use of antisense $RNA$ technology to delay ripening.
Option $(C)$ is the correct example of gene therapy,where a functional gene for $ADA$ (adenosine deaminase) is introduced into the cells of a patient suffering from $SCID$ (Severe Combined Immunodeficiency) to replace the defective gene.
Option $(D)$ refers to the genetic modification of crops for nitrogen fixation.

(B) In $1983$,Eli Lilly,an American company,prepared two $DNA$ sequences corresponding to $A$ and $B$ chains of human insulin.
These sequences were introduced into the plasmids of $E. coli$ to produce insulin chains.
These chains were then extracted and combined by creating disulfide bonds to form human insulin (Humulin).

(D) The Assertion is incorrect because recombinant $DNA$ technology has been highly effective in producing therapeutic drugs,such as human insulin.
The Reason is also incorrect because recombinant therapeutics are designed to be identical to human proteins,thereby minimizing or preventing unwanted immunological responses that were common with non-human derived therapeutics.
Therefore,both the Assertion and the Reason are incorrect.

(B) Gene therapy is a collection of methods that allows correction of a gene defect that has been diagnosed in a child or embryo. Here,genes are inserted into a person's cells and tissues to treat a disease. Correction of a genetic defect involves the delivery of a normal gene into the individual or embryo to take over the function of and compensate for the non-functional gene.

(C) $1$. Mature insulin consists of two short polypeptide chains,chain $A$ and chain $B$,that are linked together by disulphide bridges. Thus,statement $(d)$ is correct.
$2$. Insulin is synthesized as a pro-hormone (pro-insulin),which contains an extra stretch called the $C$-peptide. This $C$-peptide is removed during maturation into insulin. Thus,statement $(a)$ is correct and statement $(c)$ is correct.
$3$. The insulin produced by $rDNA$ technology (e.g.,Humulin) is synthesized as separate $A$ and $B$ chains in $E. coli$,which are then combined to form mature insulin. It does not contain the $C$-peptide. Thus,statement $(b)$ is incorrect.
$4$. Therefore,statements $(a), (c),$ and $(d)$ are correct.

(A) Adenosine deaminase $(ADA)$ is an enzyme that is crucial for the proper functioning of the immune system.
Deficiency of this enzyme leads to Severe Combined Immunodeficiency $(SCID)$.
In $SCID$,the body's immune system is unable to fight off infections effectively because the $T$-lymphocytes and $B$-lymphocytes do not function properly.
Therefore,$ADA$ deficiency results in the dysfunction of the immune system.

(N/A) Recombinant $DNA$ technology has allowed the production of antigenic polypeptides of pathogens in bacteria or yeast.
Vaccines produced using this approach allow for large-scale production and,consequently,greater availability for immunization.
For example,the hepatitis $B$ vaccine is produced from yeast.

(C) In gene therapy for $ADA$ deficiency,functional $ADA$ genes are introduced into the patient's lymphocytes.
These lymphocytes are cultured outside the body and then re-infused into the patient.
However,these genetically engineered lymphocytes are not immortal; they have a finite lifespan and eventually die.
Therefore,the patient requires periodic infusions of these cells to maintain the production of the $ADA$ enzyme.

(D) The correct answer is $(d)$.
$(a)$ Pro-insulin consists of $A$ and $B$ chains linked by a $C$-peptide. This is correct.
$(b)$ In genetically engineered insulin (Humulin),$A$ and $B$ chains are produced separately in $E. coli$ and linked by disulfide bonds. This is correct.
$(c)$ This statement describes the historical source of insulin,not the nature of genetically engineered insulin. While true as a historical fact,it is not a characteristic of the engineered product itself.
$(d)$ Pro-insulin must undergo processing (removal of $C$-peptide) to become mature insulin. This is correct.
$(e)$ This refers to the side effects of animal-derived insulin,not the nature of genetically engineered insulin.
Therefore,statements $(a), (b),$ and $(d)$ are the correct descriptions regarding the production and nature of genetically engineered insulin.

(A) The Hepatitis-$B$ vaccine is a recombinant $DNA$ vaccine.
It is produced using genetic engineering techniques.
The gene coding for the Hepatitis-$B$ surface antigen $(HBsAg)$ is inserted into the genome of yeast cells (typically $Saccharomyces$ $cerevisiae$).
These yeast cells then express the antigen, which is harvested and purified to create the vaccine.
Therefore, the correct source is yeast.

(B) $MRI$ stands for Magnetic Resonance Imaging.
It utilizes strong magnetic fields and non-ionizing radiations (radio waves) to generate detailed images of the internal structures of the body.
Unlike $X$-rays or $CT$ scans,$MRI$ does not use ionizing radiation,making it a safer diagnostic tool for detecting pathological or physiological changes in living tissues.

(D) Biotechnology involves the use of genetically modified organisms $(GMOs)$ to produce biological products on an industrial scale.
These organisms include microorganisms (like bacteria and yeast),fungi,and genetically modified plants and animals.
By manipulating the genetic material of these organisms,scientists can make them produce specific proteins,enzymes,hormones,or vaccines required for medical and industrial purposes.
Therefore,all the listed categories are used in modern biotechnology.

(A) According to the $NCERT$ textbook for Class $12$ Biology,Chapter $12$ (Biotechnology and its Applications),there are about $30$ recombinant therapeutics that have been approved for human use the world over.
Out of these,$12$ are presently being marketed in India.
Therefore,the correct option is $A$.

(A) The first human medicine produced using recombinant $DNA$ technology is insulin. In $1983$,Eli Lilly,an American company,prepared two $DNA$ sequences corresponding to $A$ and $B$ chains of human insulin and introduced them in plasmids of $E. coli$ to produce insulin chains. These chains were then extracted and combined by creating disulfide bonds to form human insulin,known as Humulin.

(C) Pro-insulin is synthesized as a pro-hormone which contains an extra stretch called the $C$-peptide.
In the given figure,$P$ represents the $A$-peptide,$Q$ represents the $C$-peptide,and $R$ represents the $B$-peptide.
$A$ and $B$ peptides are linked together by disulfide bridges to form mature insulin,while the $C$-peptide is removed during maturation.
Therefore,the correct sequence is $A, C, B$.

(C) Insulin is synthesized in the human body as a pro-hormone,which contains an extra stretch called the $C$-peptide.
During the maturation process,this $C$-peptide is removed from the pro-insulin to form mature insulin.
Therefore,mature insulin consists only of the $A$ and $B$ polypeptide chains linked by disulfide bridges,and it lacks the $C$-peptide.

(C) In $1983$,the American company $Eli$ $Lilly$ produced two $DNA$ sequences corresponding to $A$ and $B$ chains of human insulin and introduced them in plasmids of $Escherichia$ $coli$ to produce insulin chains. These chains were then extracted and combined by creating disulfide bonds to form human insulin.

(B) The first clinical gene therapy was performed in $1990$ on a $4$-year-old girl suffering from Adenosine Deaminase $(ADA)$ deficiency.
$ADA$ deficiency is caused by the deletion of the gene for adenosine deaminase,which is crucial for the proper functioning of the immune system.
This condition leads to Severe Combined Immunodeficiency $(SCID)$,where the patient lacks functional $T$-lymphocytes.
Therefore,the correct option is $B$.

(A) $ADA$ deficiency (Adenosine Deaminase deficiency) is a genetic disorder caused by the deletion of the gene for adenosine deaminase.
$1$. Enzyme replacement therapy involves the periodic injection of functional $ADA$ into the patient. It does not provide a permanent cure because the patient's own cells do not produce the enzyme.
$2$. Bone marrow transplantation can be curative if performed early,but it is not always successful due to the difficulty in finding a suitable donor.
$3$. Gene therapy is considered a potential permanent cure because it involves introducing functional $ADA$ cDNA into the patient's lymphocytes,which are then cultured and returned to the patient.
Since enzyme replacement therapy requires repeated administration and is not a permanent cure,it is the primary answer in this context.

(C) Adenosine Deaminase $(ADA)$ is an enzyme that is crucial for the proper functioning of the immune system.
It is responsible for the breakdown of adenosine into deoxyadenosine in the body.
$A$ deficiency of this enzyme leads to a disorder known as Severe Combined Immunodeficiency $(SCID)$,which results in a lack of functional $T$-lymphocytes and $B$-lymphocytes,making the individual highly susceptible to infections.
Therefore,$ADA$ is essential for the immune system.

(D) In the treatment of $ADA$ (Adenosine Deaminase) deficiency,lymphocytes are extracted from the patient's blood and a functional $ADA$ gene is introduced into them. These genetically engineered cells are not immortal and have a limited lifespan. Furthermore,over time,the introduced gene may be lost from these cells or the cells may die. Therefore,to provide continuous treatment,these genetically engineered lymphocytes must be periodically reintroduced into the patient's body. Thus,the correct option is $D$.

(C) The permanent cure for $ADA$ (Adenosine Deaminase) deficiency is gene therapy.
In this method,lymphocytes from the blood of the patient are grown in a culture outside the body.
$A$ functional $ADA$ $cDNA$ is then introduced into these lymphocytes using a retroviral vector.
These genetically engineered cells are then returned to the patient.
However,since these cells are not immortal,the patient requires periodic infusion of such genetically engineered lymphocytes.
If the gene isolate from marrow cells producing $ADA$ is introduced into cells at early embryonic stages,it could be a permanent cure.

(C) Early diagnosis is essential for the effective treatment of diseases. Conventional methods of diagnosis like serum and urine analysis generally do not detect diseases until symptoms become visible.
Modern molecular diagnostic techniques such as $rDNA$ technology,$PCR$ (Polymerase Chain Reaction),and $ELISA$ (Enzyme-Linked Immunosorbent Assay) allow for the early detection of pathogens and genetic disorders even before symptoms appear.
Therefore,$P$ (Early diagnosis) includes $I, III, V$ and $Q$ (Not capable of early diagnosis) includes $II, IV$.

(B) $ELISA$ (Enzyme-Linked Immunosorbent Assay) is a diagnostic technique that relies on the principle of antigen-antibody interactions.
In this method,the presence of a pathogen is detected by the presence of antigens (proteins,glycoproteins,etc.) or by detecting antibodies synthesized against the pathogen.
$PCR$ (Polymerase Chain Reaction) works on the principle of $DNA$ amplification,not antigen-antibody interaction.

(D) Emphysema is a chronic respiratory disorder caused by the deficiency of the protein $\alpha-1-$antitrypsin.
This protein inhibits the activity of elastase,an enzyme that breaks down the alveolar walls in the lungs.
In patients with emphysema,the lack of this inhibitor leads to the destruction of lung tissue.
Therefore,$\alpha-1-$antitrypsin is used as a therapeutic protein to treat this condition.

(C) The correct answer is option $C$ because conventional methods of diagnosis,such as serum and urine analysis,are not sensitive enough to detect pathogens or diseases at very low concentrations,thus failing to aid in early diagnosis.
In contrast,modern molecular diagnostic techniques like Recombinant $DNA$ Technology,Polymerase Chain Reaction $(PCR)$,and Enzyme Linked Immuno-Sorbent Assay $(ELISA)$ are highly sensitive and specific,allowing for the detection of diseases long before symptoms appear,which is crucial for early treatment.

(B) The correct matches are as follows:
$A. \alpha-1$ antitrypsin is a protein used to treat $III. \text{Emphysema}$.
$B. \text{Cry } IAb$ is a gene used to control $IV. \text{Corn borer}$.
$C. \text{Cry } IAc$ is a gene used to control $I. \text{Cotton bollworm}$.
$D. \text{Enzyme replacement therapy}$ is a treatment method used for $II. ADA \text{ deficiency}$.
Therefore, the correct sequence is $A-III, B-IV, C-I, D-II$.

(A) In $1983$, the American company Eli Lilly prepared two $DNA$ sequences corresponding to $A$ and $B$ chains of human insulin and introduced them in plasmids of $Escherichia \text{ } coli$ to produce insulin chains. $E. \text{ } coli$ is a bacterium. These chains were produced separately, extracted, and combined by creating disulfide bonds to form human insulin (Humulin).

(B) Insulin is a peptide hormone composed of amino acids.
When insulin is taken orally,it enters the digestive system where it is exposed to various proteolytic enzymes (such as pepsin and trypsin) in the stomach and small intestine.
These enzymes break down the peptide bonds of the insulin molecule,effectively digesting it into its constituent amino acids before it can be absorbed into the bloodstream.
Therefore,oral administration renders insulin ineffective,necessitating its delivery via injection.

(B) Statement $(i)$ is incorrect because mature insulin consists only of chain $A$ and chain $B$. The $C$-peptide is removed during maturation.
Statement $(ii)$ is correct. Proinsulin contains an extra stretch called the $C$-peptide,which is removed during the maturation process to form mature insulin.
Statement $(iii)$ is incorrect. Mature insulin does not contain the $C$-peptide.
Statement $(iv)$ is correct. The two polypeptide chains,$A$ and $B$,are linked together by disulphide bridges.
Therefore,only statements $(ii)$ and $(iv)$ are correct. The total number of correct statements is $2$.

(D) Statement-$I$ is incorrect because,as per the $NCERT$ textbook,there are about $30$ recombinant therapeutics that have been approved for human use the world over,not specifically in India.
Statement-$II$ is correct because recombinant $DNA$ technology allows for the production of human-identical proteins,which do not trigger the unwanted immunological responses often seen with proteins isolated from non-human sources (like animal-derived insulin).
Therefore,Statement-$I$ is incorrect and Statement-$II$ is correct.

(C) Let us analyze each statement:
$I.$ Incorrect: Humulin (human insulin) is produced by inserting human insulin genes into $E. coli$,not $Agrobacterium$.
$II.$ Correct: The Indian government has set up the Genetic Engineering Approval Committee $(\text{GEAC})$ to make decisions regarding the validity of $GM$ research and the safety of introducing $GM$ organisms for public services.
$III.$ Incorrect: $\alpha-1$-antitrypsin is used to treat emphysema,not $\text{PKU}$ (Phenylketonuria).
$IV.$ Correct: $\text{ELISA}$ (Enzyme-Linked Immunosorbent Assay) is based on the principle of antigen-antibody interaction and is used for the early diagnosis of diseases.
$V.$ Incorrect: Flavr-savr is a genetically modified variety of tomato,not pomato.
Therefore,statements $I$,$III$,and $V$ are incorrect. The total number of incorrect statements is $3$.

(D) Biotechnology is defined as the integration of natural science and organisms,cells,parts thereof,and molecular analogues for products and services.
Statement-$I$ is correct: In vitro fertilisation $(IVF)$ involves the manipulation of gametes and embryos outside the body,which falls under the scope of biotechnology.
Statement-$II$ is correct: The development of $\text{DNA}$ vaccines involves genetic engineering techniques to introduce specific genetic material into the body to trigger an immune response,which is a core application of biotechnology.
Therefore,both statements are correct.

(C) The first clinical gene therapy was given in $1990$ to a $4$-year-old girl suffering from Adenosine Deaminase $(ADA)$ deficiency.
$ADA$ deficiency is caused by the deletion of the gene for adenosine deaminase.
This enzyme is crucial for the proper functioning of the immune system.
In this therapy,lymphocytes from the patient's blood were grown in a culture outside the body,and a functional $ADA$ $cDNA$ was introduced into these lymphocytes,which were then returned to the patient.

(D) The correct matches are as follows:
$1$. Genetically engineered Human Insulin is produced using $\text{E. coli}$ bacteria $(A-II)$.
$2$. $\text{GM}$ Cotton (Bt Cotton) is engineered using the bacterium $\text{Bacillus thuringiensis}$ $(B-IV)$.
$3$. $\text{ADA}$ (Adenosine Deaminase) deficiency is treated using Gene therapy $(C-I)$.
$4$. $\text{ELISA}$ (Enzyme-Linked Immunosorbent Assay) is a diagnostic technique based on the principle of Antigen-antibody interaction $(D-III)$.
Therefore,the correct sequence is $A-II, B-IV, C-I, D-III$.

(A) The diagram illustrates the process of maturation of proinsulin into functional insulin.
Proinsulin consists of three polypeptide chains: $A$,$B$,and $C$.
The $C$-peptide is an extra stretch of amino acids that is removed during the maturation process to form mature insulin,which consists of two polypeptide chains,$A$ and $B$,linked together by disulfide bridges.

(C) The Indian Parliament cleared the $Third$ amendment of the Indian Patent Bill. This amendment was significant in the context of biotechnology and intellectual property rights,as it addresses issues related to patent terms and emergency provisions,which are crucial for the regulation of biological resources and biotechnological inventions.

(C) $\text{ELISA}$ stands for $\text{Enzyme-Linked Immunosorbent Assay}$.
It is a widely used molecular diagnostic technique.
It is based on the principle of antigen-antibody interaction.
In this technique,an enzyme is linked to an antibody,and the presence of an antigen or antibody is detected by the color change produced by the enzyme's action on a substrate.
Therefore,option $C$ is the correct description.

(B) The correct matching is as follows:
$(a)$ Eli Lilly is a company that produced human insulin (Humulin) using recombinant $DNA$ technology. Thus,$a-ii$.
$(b)$ $Bt$ stands for Bacillus thuringiensis,a bacterium used in genetic engineering for pest resistance. Thus,$b-i$.
$(c)$ Gene therapy is used to treat genetic disorders like Adenosine deaminase $(ADA)$ deficiency. Thus,$c-iv$.
$(d)$ $\text{RNAi}$ ($RNA$ interference) is a method used to protect plants from nematodes like Meloidogyne incognita. Thus,$d-iii$.
Therefore,the correct sequence is $a-ii, b-i, c-iv, d-iii$.

(B) The Assertion is True. Mature insulin is formed from pro-insulin,which contains an extra stretch called the $C$-peptide. During maturation,this $C$-peptide is removed to form functional insulin.
The Reason is also True. Historically,insulin for diabetic patients was extracted from the pancreas of slaughtered cattle and pigs. However,this method had limitations,such as causing allergic reactions in some patients.
While both statements are factually correct,the Reason does not explain why $C$-peptide is absent in mature insulin. The absence of $C$-peptide is due to the post-translational processing of pro-insulin,not because of the source of insulin extraction. Therefore,the Reason is not the correct explanation for the Assertion.

(A) $ELISA$ stands for Enzyme-Linked Immunosorbent Assay.
It is a diagnostic technique used to detect the presence of specific antigens or antibodies in a sample.
The fundamental principle of $ELISA$ is the specific interaction between an antigen and an antibody.
In this process,an enzyme is linked to an antibody or antigen,and the reaction produces a detectable signal (usually a color change) when the target molecule is present.

(A) The deficiency referred to is $Adenosine$ $Deaminase$ $(ADA)$ deficiency,which causes Severe Combined Immunodeficiency $(SCID)$.
This condition can be cured by bone marrow transplantation,where the patient's defective immune cells are replaced by healthy stem cells from a donor.
Therefore,the correct option is $A$.

(D) The correct answer is $D$. $\alpha-1$ antitrypsin is a proteinase inhibitor used to treat emphysema. Emphysema is a chronic respiratory disorder in which alveolar walls are damaged due to which respiratory surface is decreased. This protein is produced through transgenic animals (specifically sheep) to treat this deficiency.

(D) Mature insulin consists of two short polypeptide chains: chain $A$ and chain $B$.
These two chains are linked together by two inter-chain disulphide bonds.
Additionally,there is an intra-chain disulphide bond within chain $A$.
Therefore,the correct answer is $D$.

(C) The correct answer is $C$. In the treatment of $ADA$ (Adenosine Deaminase) deficiency using gene therapy,lymphocytes are extracted from the patient's blood. These cells are then cultured in vitro,and a functional $ADA$ $cDNA$ is introduced into them using a retroviral vector. The genetically modified lymphocytes are then returned to the patient's body. Since these cells are not immortal,the patient requires periodic infusions of such genetically engineered lymphocytes.

(A) The first human hormone produced using recombinant $DNA$ technology is $Insulin$.
In $1983$,an American company named $Eli$ $Lilly$ prepared two $DNA$ sequences corresponding to $A$ and $B$ chains of human insulin and introduced them in plasmids of $E. coli$ to produce insulin chains.
These chains were then extracted and combined by creating disulfide bonds to form human insulin,which is commercially known as $Humulin$.

(B) The $ELISA$ $(Enzyme-Linked Immunosorbent Assay)$ method is a diagnostic technique used to detect the presence of specific antigens or antibodies in a sample.
It is based on the principle of $Antigen-Antibody$ interaction,where an enzyme-linked antibody binds to a specific antigen,and the subsequent enzymatic reaction produces a detectable signal (usually a color change).
Therefore,the correct principle is $Antigen-Antibody$ interaction.

(C) In mammals,including humans,insulin is synthesized as a pro-hormone called pro-insulin.
Pro-insulin consists of three polypeptide chains: $A$,$B$,and $C$.
The $C$-peptide is an extra stretch of amino acids that is removed during the maturation process of pro-insulin into mature insulin.
Therefore,mature insulin consists only of $A$ and $B$ polypeptide chains linked by disulfide bridges,and the $C$-peptide is absent.