Read the following statements.

I. Pigs are being developed for use in testing the safety of vaccines before they are used on humans.

II. A transgene is a foreign gene that, when incorporated into a host cell, makes it transgenic.

III. The first clinical gene therapy was given in 1990 to a 4-year old girl with adenosine deaminase (ADA) deficiency.

IV. The two insulin polypeptides are connected through hydrogen bonds.

Which of the above statements are correct?

II and III

The correct answer is Option (2) - II and III

I. Pigs are being developed for use in testing the safety of vaccines before they are used on humans is incorrect. Transgenic mice are being developed for use in testing the safety of vaccines before they are used on humans. 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.

II. A transgene is a foreign gene that, when incorporated into a host cell, makes it transgenic is correct.

A transgene is a gene that comes from a different species or organism and is introduced into the genome of another organism, known as the host cell. When the host cell incorporates this foreign gene, it becomes transgenic, as it now contains genetic material from two different sources. The introduction of transgenes is a fundamental process in genetic engineering, enabling the manipulation of an organism's genetic makeup to introduce specific traits or functions.

III. The first clinical gene therapy was given in 1990 to a 4-year old girl with adenosine deaminase (ADA) deficiency is correct.

Gene therapy is a collection of methods that allows correction of a gene defect that has been diagnosed in a child/embryo. Here genes are inserted into a person’s cells and tissues to treat a disease. Correction of a genetic defect involves delivery of a normal gene into the individual or embryo to take over the function of and compensate for the non-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 crucial for the immune system to function. The disorder is caused due to the deletion of the gene for adenosine deaminase.

IV. The two insulin polypeptides are cross-linked via hydrogen bonds is incorrect.

Insulin is a hormone produced by the pancreas that plays a crucial role in regulating blood sugar levels. It is composed of two polypeptide chains, referred to as chain A and chain B. These chains are connected to each other through disulfide bridges, not hydrogen bonds. The disulfide bridges help maintain the three-dimensional structure of insulin, allowing it to function effectively in the body to regulate glucose metabolism.