Biotechnology: Principles and Processes
Read the following passage carefully and answer the given questions.
Biotechnology deals with large scale production and marketing of products and processes using live organisms, cells or enzymes. Modern biotechnology using genetically modified organisms was made possible only when man learnt to alter the chemistry of DNA and construct recombinant DNA. This key process is called recombinant DNA technology or genetic engineering. This process involves the use of restriction endonucleases, DNA ligase, appropriate plasmid or viral vectors to isolate and ferry the foreign DNA into host organisms, expression of the foreign gene, purification of the gene product, i.e., the functional protein and finally making a suitable formulation for marketing. Restriction endonucleases are used in genetic engineering to form ‘recombinant’ molecules of DNA, which are composed of DNA from different sources (genomes). Vectors used at present, are engineered in such a way that they help easy linking of foreign DNA and selection of recombinants from non-recombinants.
In a gene gun method, cells are bombarded with high velocity micro-particles of -
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Tungsten
In the gene gun (biolistics) method, which suits plants, tiny particles coated with DNA are fired at the cells at high speed. The particles carry the DNA into the cell. NCERT names two metals for the particles, gold and tungsten.
(1) Tungsten — Correct. In the gene gun, plant cells are bombarded with high velocity micro-particles of gold or tungsten coated with DNA. Tungsten is one of these two metals.
Note: This passage is taken from NCERT as it is. Most CUET (UG) questions come straight from NCERT, so study the book line by line, including figures and their titles.
NCERT Extract:
Cloning Vectors – “… Recombinant DNA can then be forced into such cells by incubating the cells with recombinant DNA on ice, followed by placing them briefly at 420C (heat shock), and then putting them back on ice. This enables the bacteria to take up the recombinant DNA. This is not the only way to introduce alien DNA into host cells. In a method known as micro-injection, recombinant DNA is directly injected into the nucleus of an animal cell. 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.”