Transgenic Animals Questions in English

(D) The transgenic cow 'Rosie', produced in $1997$, was the first transgenic cow to produce human protein-enriched milk.
Her milk contained the human alpha-lactalbumin protein.
The concentration of this human protein in her milk was $2.4 \, gm$ per liter.
Therefore, the correct option is $D$.

(A) Transgenic mice are used to test the safety of vaccines before they are used on humans.
For example,transgenic mice are being used to test the safety of the polio vaccine.
If successful and found to be reliable,they could replace the use of monkeys to test the safety of batches of the vaccine.

(A) Transgenic mice are being used to test the safety of vaccines before they are used on humans. The first vaccine to be tested using transgenic mice was the polio vaccine. This method is considered more reliable than using monkeys,which were previously used for safety testing.

(B) Before vaccines are administered to humans,they are tested on transgenic animals to check their safety. Transgenic mice are developed for use in testing the safety of vaccines before they are used on humans. If the testing on transgenic mice is successful,the next step involves testing on other animals,such as monkeys,to further evaluate the safety and efficacy of the vaccine before clinical trials in humans.

(B) Chemical safety testing is a procedure used to determine the toxicity of various chemicals and drugs before they are released for human use.
Transgenic animals are specifically designed to carry foreign genes that make them more sensitive to toxic substances than non-transgenic animals.
By exposing these transgenic animals to toxic chemicals,researchers can observe the effects and assess the safety of the substances more efficiently and accurately.
Therefore,the correct option is testing for toxicity of drugs.

(C) Transgenic animals are designed to study the effects of genes on the development of diseases.
Some transgenic animals are created to be sensitive to certain toxic substances.
By exposing these animals to such substances,researchers can observe the toxic effects and study the underlying biological mechanisms.
Therefore,the genes are modified to make the animals sensitive $(Y)$ to specific toxic $(X)$ substances.

(C) The first mammal to be successfully cloned from an adult somatic cell was a sheep named $Dolly$.
This experiment was conducted by $Ian \text{ } Wilmut$ and his colleagues at the $Roslin \text{ } Institute$ in $Scotland$.
The cloning process involved the technique of somatic cell nuclear transfer $(SCNT)$.

(D) Anthrax is a severe infectious bacterial disease caused by the bacterium $Bacillus$ $anthracis$.
Clinical signs of anthrax in cattle include high fever,increased respiration,and the characteristic discharge of dark,unclotted blood from natural body openings like the mouth,nose,and anus.
This condition is highly fatal and requires immediate veterinary intervention.

(C) Genetic engineering is the branch of biotechnology that involves the manipulation of an organism's genome by introducing foreign genes to achieve desired traits or products.
Tissue culture refers to the large-scale propagation of tissues or organisms in vitro within a short period.
Euphenics is the science that deals with the improvement of human morphology or phenotype through environmental changes rather than genetic alteration.
Immunisation is the process by which an individual's immune system becomes fortified against an infectious agent,typically through vaccination.

(D) Transgenic organisms are those whose genetic material has been altered using genetic engineering techniques to introduce a foreign gene.
$1$. $Flavr$ $Savr$ tomato was the first genetically modified food crop,engineered to have a longer shelf life by delaying the ripening process.
$2$. $Bt$ cotton is a transgenic crop that contains a gene from the bacterium $Bacillus$ $thuringiensis$ $(Bt)$,which produces an insecticidal protein that protects the plant from bollworms.
$3$. Dolly the sheep was the first mammal to be cloned from an adult somatic cell,but she was not a transgenic organism.
Therefore,$Flavr$ $Savr$ tomato and $Bt$ cotton are examples of transgenic organisms.

(B) The donor nucleus $(2n)$ from a sheep $A$ udder cell (somatic cell) was fused with an enucleated sheep $B$ egg cell (gamete containing only cytoplasm) to form a diploid cell,which simulates a fertilized egg.
This cell was then induced to divide in vitro to form an $8$-celled embryo,which was subsequently implanted into the uterus of a foster mother.

(C) Transgenic organisms,also known as genetically modified organisms $(GMOs)$,are organisms whose genetic material has been altered using genetic engineering techniques.
This process involves the introduction of a foreign gene (a transgene) from another organism into the genome of the host organism.
The introduced gene provides the host with new traits or characteristics that it did not possess naturally.
Therefore,the correct method for producing transgenic organisms is by introducing foreign genes.

(B) $PCR$ (Polymerase Chain Reaction) is a technique used for $DNA$ amplification,not for restriction endonucleases.
Rosie cow is a well-known example of a transgenic animal that produces human protein-enriched milk.
Gene therapy was first used to treat $ADA$ (Adenosine Deaminase) deficiency,not emphysema.
$Bt$ Cotton is the transgenic plant associated with Bacillus thuringiensis,not tobacco.

(B) Transgenic animals are defined as animals that have had their $DNA$ manipulated to possess and express an extra (foreign) gene. This foreign $DNA$ is introduced into the germline or early embryonic cells,ensuring that it is present in all the cells of the organism's body.

(A) Useful biological products can be produced by introducing into transgenic animals the portion of $DNA$ (or genes) which codes for a particular product.
For example, the human protein $\alpha-1$ antitrypsin is used to treat emphysema.

(A) In $1997$,the first transgenic cow,named Rosie,was produced.
Rosie produced human protein-enriched milk containing human alpha-lactalbumin.
The concentration of this protein in the milk was $2.4 \ g/L$.
This milk was nutritionally more balanced for human babies compared to natural cow milk.

(A) The gene for human $\alpha$-lactalbumin was introduced into the genome of the first transgenic cow (Rosie).
This modification resulted in the production of milk that was nutritionally richer and more balanced for human infants compared to natural cow milk.

(D) Animals whose $DNA$ is manipulated to possess and express an extra (foreign) gene are known as transgenic animals. The common reasons for developing transgenic animals include:
$(i)$ Study of normal physiology and development: Transgenic animals are used to study how genes are regulated and how they affect the normal functions of the body and its development, e.g., study of complex growth factors like insulin-like growth factor.
$(ii)$ Study of diseases: Transgenic models have been developed for many human diseases such as cancer, cystic fibrosis, rheumatoid arthritis, and Alzheimer's disease to understand the disease mechanism.
$(iii)$ Obtaining useful biological products: Transgenic animals can be used to produce biological products, e.g., human protein ($\alpha-1$-antitrypsin) is used to treat emphysema.
$(iv)$ Vaccine safety: Transgenic mice are developed to test the safety of vaccines before they are used on humans, e.g., the polio vaccine.
$(v)$ Chemical safety testing: Transgenic animals are designed to carry genes that make them more sensitive to toxic substances than non-transgenic animals, allowing for faster toxicity testing.
Since all the statements ($I, II, III, IV,$ and $V$) are correct, the correct option is $D$.

(D) Transgenic animals are animals that have had their $DNA$ manipulated to possess and express an extra (foreign) gene.
Transgenic models exist for many human diseases such as cancer,cystic fibrosis,rheumatoid arthritis,and Alzheimer's disease.
These models are used to study the disease,understand the role of genes in the disease,and test new treatments.
Therefore,all four listed diseases have transgenic models developed for them.
The correct option is $D$.

(A) Statement $I$ is correct: Transgenic animals are specifically designed to carry genes that make them more sensitive to toxic substances,allowing for the testing of toxicity and safety of drugs.
Statement $II$ is correct: Useful biological products can be produced by introducing the specific $DNA$ sequence (gene) that codes for a desired protein into transgenic animals. For example,human protein $\alpha-1$-antitrypsin is used to treat emphysema.
Statement $III$ is correct: Brazzein is a protein produced by the West African plant $Pentadiplandra$ $brazzeana$,which is approximately $2000$ times as sweet as sugar. It is used as a low-calorie sweetener.
Therefore,all three statements are correct.

(D) In $1997$,the first transgenic cow,'Rosie',was produced.
Rosie produced human protein-enriched milk containing $2.4 \text{ g/L}$ of protein.
The milk contained the human $\alpha$-lactalbumin,which made it nutritionally more balanced for human babies compared to natural cow milk.
Therefore,all three statements ($I$,$II$,and $III$) are correct.

(C) Transgenic animals are defined as organisms whose $DNA$ has been manipulated through genetic engineering techniques to possess and express an extra or foreign gene (transgene). This process allows the animal to exhibit new traits or produce specific proteins.

(B) Transgenic animals are animals that have had their $DNA$ manipulated to possess and express an extra (foreign) gene.
Among all the transgenic animals produced for research and medical purposes,mice constitute the vast majority.
It is estimated that approximately $95\%$ of all existing transgenic animals are mice,as they are widely used as models for human diseases due to their genetic similarity and short reproductive cycle.

(C) Transgenic animals that produce useful biological products can be created by the introduction of the portion of $DNA$ which codes for a particular product.
For example,the human protein $\alpha-1$-antitrypsin is used to treat emphysema.
This protein is produced by transgenic animals,which helps in managing the condition effectively.

(D) Rosie is a transgenic cow that produces human protein-enriched milk.
Its milk contains human $\alpha$-lactalbumin and is nutritionally more balanced for human babies than natural cow milk.
The protein content of this milk is $2.4 \; g/L$.
Rosie was produced for the first time in the year $1997$,not $2001$.
Therefore,the statement that it was produced in $2001$ is incorrect.

(B) The figure shows a normal mouse and a 'Supermouse'.
The 'Supermouse' is a transgenic organism,meaning it has had foreign $DNA$ introduced into its genome.
In this specific case,the gene for the human growth hormone $(hGH)$ was introduced into the mouse genome.
The expression of this introduced human growth hormone gene leads to increased growth,resulting in a mouse that is significantly larger than its non-transgenic counterpart.

(A) Transgenic mice have been developed to serve as models for human diseases and to test the safety of vaccines before they are used on humans.
Specifically,transgenic mice are used to test the safety of the polio vaccine.
This development is significant because it provides a reliable alternative to using monkeys,which were previously used to test the safety of vaccine batches.
Therefore,both the Assertion and the Reason are correct,and the Reason provides the correct explanation for why transgenic mice are used in this context.

(A) Dolly was the first mammal cloned from an adult somatic cell (udder cell) by Ian Wilmut and Keith Campbell in $1996$.
To create Dolly,three sheep were involved: one provided the nucleus from an udder cell,one provided the enucleated egg cell,and the third served as the surrogate mother.
Both the Assertion and the Reason are factually correct,and the Reason explains the process used to create the cloned mammal mentioned in the Assertion.

(A) Transgenic animals are animals that have had their $DNA$ manipulated to possess and express an extra (foreign) gene.
Among all transgenic animals,mice are the most commonly created and used in research.
This is because they are easy to handle,have a short reproductive cycle,and their genetic makeup is well-understood,making them ideal models for studying human diseases and testing new therapies.

(D) Transgenic animals are specifically designed to allow the study of how genes are regulated and how they affect the normal functions of the body and its development.
$1$. They help in studying complex growth factors like insulin-like growth factors.
$2$. They allow researchers to study the biological effects induced by alterations in the formation of these factors.
$3$. They are essential for understanding the biological role of specific factors in the body.
Therefore,all the mentioned aspects are studied using transgenic animals.

(B) Transgenic animals are specifically designed to allow the study of genes and how they affect the development of diseases.
They serve as models for human diseases to understand the disease pathogenesis and to test new treatments.
According to the $NCERT$ textbook,transgenic models exist for the following diseases:
$1$. Cancer
$2$. Cystic fibrosis
$3$. Rheumatoid arthritis
$4$. Alzheimer's disease
Therefore,there are $4$ such diseases listed.
Thus,the correct option is $B$.

(A) The first transgenic cow,named 'Rosie',was produced in the year $1997$.
This cow was engineered to produce human protein-enriched milk,specifically containing human alpha-lactalbumin,which is nutritionally more balanced for human babies than natural cow milk.

(C) The transgenic cow 'Rosie', produced in $2002$, was the first cow to produce human protein-enriched milk.
It contains the human alpha-lactalbumin protein.
The concentration of this human protein in the milk of 'Rosie' is $2.4 \text{ g/L}$.
Therefore, the correct option is $C$.

(B) The transgenic cow named 'Rosie' was produced in $1997$.
This cow was genetically engineered to produce human protein-enriched milk.
The milk produced by 'Rosie' contained the human protein $\alpha$-lactalbumin at a concentration of $2.4 \ g/L$.
This protein is nutritionally more balanced for human babies than natural cow milk.

(C) Transgenic mice are being developed for use in testing the safety of vaccines before they are used on humans.
Specifically,transgenic mice are used to test the safety of the polio vaccine.
This allows researchers to assess the efficacy and safety of the vaccine in a controlled environment without risking human lives during the initial testing phases.

(A) Transgenic animals are used to test the safety of vaccines before they are used on humans.
Specifically,transgenic mice are developed for use in testing the safety of vaccines.
Once the vaccine is proven safe in these transgenic models,it is then tested on larger animals like transgenic monkeys before being approved for human use.
Therefore,the correct sequence is transgenic mice followed by transgenic monkeys.

(B) Transgenic animals are specifically designed to be more sensitive to toxic substances than non-transgenic animals. This increased sensitivity allows researchers to observe the toxic effects of chemicals or drugs more rapidly and accurately. Therefore,the statement that genes are made 'insensitive' to toxic substances is incorrect. The actual process involves introducing genes that make the animals more susceptible to the toxic effects,facilitating faster testing.

(B) The transgenic cow '$Rosie$',produced in $1997$,was the first transgenic cow. Its milk contained the human protein alpha-lactalbumin. This protein makes the milk nutritionally more balanced for human babies compared to natural cow milk,as it closely mimics the composition of human breast milk.

(B) Transgenic animals are those whose $\text{DNA}$ has been manipulated to possess and express an extra (foreign) gene.
They are specifically designed to allow the study of how genes are regulated and how they affect the normal functions of the body and its development.
They are also used to study the complex factors involved in the development of diseases like cancer,cystic fibrosis,rheumatoid arthritis,and Alzheimer's.
Transgenic mice are specifically developed for use in testing the safety of vaccines before they are used on humans.
Therefore,the statement that transgenic animals cannot be designed to study gene regulation is incorrect.

(D) Transgenic animals are animals that have had their $DNA$ manipulated to possess and express an extra (foreign) gene. Their uses include:
$1$. Study of normal physiology and development: Transgenic animals allow for the study of how genes are regulated and how they affect the normal functions of the body and its development.
$2$. Study of disease: Many transgenic animals are designed to increase our understanding of how genes contribute to the development of diseases.
$3$. Biological products: Transgenic animals can be used to produce biological products like medicines (e.g.,alpha$-1-$antitrypsin for emphysema) by introducing genes that code for a particular human protein.
$4$. Vaccine safety: Transgenic mice are being used to test the safety of vaccines before they are used on humans.
$5$. Chemical safety testing: This is known as toxicity/safety testing.
Molecular diagnosis (such as $PCR$,$ELISA$,or recombinant $DNA$ technology) is a technique used to detect the presence of pathogens or genetic disorders in patients,but it is not a use of transgenic animals.

(D) Transgenic animals are animals that have had their $DNA$ manipulated to possess and express an extra (foreign) gene.
These animals are specifically designed to allow the study of genes and how they affect the normal functions of the body and its development.
Transgenic models have been developed for many human diseases to serve as research tools for understanding the disease mechanism and testing new therapies.
Specifically,transgenic models exist for:
$(a)$ Cancer: Used to study oncogenes and tumor suppressors.
$(b)$ Cystic fibrosis: Used to study the genetic basis of the disease.
$(c)$ Rheumatoid arthritis: Used to study autoimmune responses.
$(d)$ Alzheimer's disease: Used to study the accumulation of amyloid plaques.
$(e)$ Emphysema: Used to study the destruction of lung tissue.
Therefore,all the listed diseases have transgenic models developed for research purposes.

(C) The Assertion is true because transgenic animals are defined as those whose $\text{DNA}$ has been manipulated to introduce and express an extra (foreign) gene.
The Reason is false because transgenic animals are often created to study the effects of toxic substances on human health,making them more sensitive or useful models for testing,not necessarily less sensitive. Furthermore,the primary purpose of creating transgenic animals is not limited to toxicity testing; it includes studying normal physiology,disease models,biological products,and vaccine safety.

(D) The correct answer is $D$. Transgenic animals are primarily used for biological research,studying disease mechanisms,testing the safety of vaccines,and producing biological products like human proteins (e.g.,alpha-$1$ antitrypsin for emphysema). While they help in understanding the genetic basis of diseases,they are not used for the direct diagnosis of genetic diseases in humans.

(B) The first transgenic cow,named 'Rosie',was produced in $1997$.
This cow produced human protein-enriched milk.
The milk contained the human protein 'Alpha-lactalbumin',which is nutritionally more balanced for human babies than natural cow milk.
Therefore,the correct option is $B$.

(C) The first transgenic cow,named 'Rosie',was produced in $1997$.
This cow produced human protein-enriched milk.
The milk contained the human alpha-lactalbumin protein,which is nutritionally more balanced for human babies than natural cow milk.
Therefore,the correct option is $C$.

(D) The transgenic cow 'Rosie', produced in $1997$, was the first transgenic cow to produce human protein-enriched milk.
Rosie's milk contained the human alpha-lactalbumin protein.
The concentration of this human protein in her milk was $2.4 \text{ gm}$ per litre.
Therefore, the correct option is $D$.

(A) Genetic engineering,specifically the creation of transgenic animals,has significant applications in medicine and research.
$1$. Transgenic mice are used to test the safety of vaccines,such as the polio vaccine,before they are administered to humans. This ensures that the vaccine is safe and effective.
$2$. Transgenic models are also used to study human diseases,including heart-related conditions,to develop new treatments.
While options $A$ and $B$ are both scientifically valid applications,in the context of standard $NCERT$ biology curriculum,the use of transgenic mice for vaccine safety testing is a primary example cited for the application of biotechnology in medicine.

(C) Rosie was the first transgenic cow produced by scientists.
She was genetically engineered to produce human protein-enriched milk,specifically containing human alpha-lactalbumin.
This milk was nutritionally more balanced for human babies than natural cow milk.

(B) The correct answer is $B$.
$\alpha-1$ antitrypsin is a human protein used to treat emphysema.
It is produced by transgenic animals,specifically transgenic sheep.
Tracy,a transgenic sheep produced in $1997$ (often cited in literature as the first transgenic farm mammal),was engineered to express this human protein in its milk,which allows for large-scale production and purification.