Target Exam

CUET

Subject

Biology

Chapter

Biotechnology -Principles and Processes

Question:

Read the following passage carefully and answer the given questions.

DNA recombinant technology involves the use of restriction endonucleases. After having cloned the gene of interest and having optimised the conditions to induce the expression of the target protein, one has to consider producing it on a large scale. The cells harbouring cloned genes of interest may be grown on a small scale in the laboratory. In order to link the alien DNA, the vector needs to have very few, preferably single, recognition sites for the commonly used restriction enzymes. Presence of more than one recognition sites within the vector will generate several fragments, which will complicate the gene cloning. In Biolistics or gene gun method cells are bombarded with high velocity micro particles of gold or tungsten coated with DNA. The ligation of alien DNA is carried out at a restriction site present in one of the two antibiotic resistance genes. For example, you can ligate a foreign DNA at the BamHI site of tetracycline resistance gene in the vector pBR322. Since the DNA is enclosed within the membranes, we have to break the cell open to release DNA along with other macromolecules such as RNA, proteins, polysaccharides and also lipids. The RNA can be removed by treatment with ribonuclease whereas proteins can be removed by treatment with protease. Other molecules can be removed by appropriate treatments and purified DNA ultimately precipitates out after the addition of chilled ethanol.

Which one of the following statements is correct with reference to biolistics?

Options:

Bombarding of cells with macro particles

Velocity of particles to be kept low

Particles are coated with DNA

Zinc and nickel particles are used

Correct Answer:

Particles are coated with DNA

Explanation:

The correct answer is Option (3) → Particles are coated with DNA 

Gene transfer involves the direct introduction of specific genes into the target organism's genome. This can be achieved using various techniques, such as microinjection, biolistics (gene gun method), or using disarmed pathogen vectors. These methods allow for precise insertion of desired genes without introducing unwanted genetic material.

In microinjection method, foreign DNA is indeed directly injected into the nucleus of an animal cell using microneedles. This is a technique used in genetic engineering to introduce foreign DNA into animal cells.

In another method, suitable for plants, cells are bombarded with high velocity micro-particles of gold or tungsten coated with DNA in a method known as biolistics or gene gun